Answer prose round 3: clean

AGENTS.md

@@ -54,6 +54,7 @@ In `docs/decisions.md`:
 - The flavour spec is read as a source
 - The node tables answer to Atlassian's schema
 - Nothing recurses unbounded
+- No value `JSON.parse` or `structuredClone` builds loops a call
 - Nothing spreads an unbounded array
 - A retry loop checks its own termination
 - Readers scan by index
@@ -168,7 +169,7 @@ reading is the ask. Never ask "A or B?": state the gap, the earlier entries of i
 nearest text, a candidate entry in that file's voice, and the instance it yields. An entry that
 keeps collecting instances is wrong: rewrite it.
 
-Which output the audience expects — README goal 5 — is settled by a reader panel rather than
+Which output the audience expects — README goal 6 — is settled by a reader panel rather than
 asked: three fresh-context readers, one per README persona the question serves, each given only
 `## Audience` and the input, writing what they expect before picking among outputs the goals
 allow, rendered, shuffled, with no rationale and nothing saying what is implemented. Three agreeing

CHANGELOG.md

@@ -17,6 +17,15 @@
   `content` or `marks` is spelled `{attrs=empty}`, `{content=empty}` or `{marks=empty}`, `-0` is
   spelled `-0`, and a `codeBlock` of several text nodes is a fence per node. A `codeBlock` holding
   other than plain text nodes rides the block carry, where it was refused.
+- **Breaking:** `unspellable-character` and `unspellable-line-start` leave `ConvertErrorCode`, and
+  `adfToMarkdown` no longer returns `unspellable-whitespace`. A carriage return in text is spelled
+  `
` and a null character `!adf:text{text="\u0000"}`; a paragraph line opening with a code span
+  is spelled as that code span, its backticks opening no fence; a code block holding either
+  character, a code span holding a null character, a text node holding no text or holding
+  `content`, and an `emoji`, `mention` or `status` whose `text` holds a line ending or a null
+  character ride the carry. See `MIGRATION.md`.
+- Fix a link `title` holding a null character: it is written as `!adf:link[text]{attrs}`, where it
+  read back as U+FFFD.
 - **Breaking:** `unspellable-link` leaves `ConvertErrorCode`; a link whose `href` or `title` no
   CommonMark escape spells is written as `!adf:link[text]{attrs}`.
 - **Breaking:** some directive refusals carry `malformed-directive` where they carried
@@ -31,8 +40,8 @@
   `collection`, `id` and `occurrenceKey` directly where they rode the opaque carry.
 - Fix an image inside another image's description: it flattens into the alt text, where it was
   refused.
-- Fix a document holding itself, through a node's `content` or an attribute: `adfToMarkdown`,
+- Fix a cyclic document, in which an object holds itself: `adfToMarkdown` and `adfToPlainMarkdown`
-  `adfToPlainMarkdown` and `isAdfDocument` refuse it as `not-an-adf-document`, where they hung.
+  refuse it as `not-an-adf-document` and `isAdfDocument` returns `false`, where all three hung.
 
 ## 0.1.0
 

MIGRATION.md

@@ -62,12 +62,20 @@ Markdown the spelling table leaves alone, which `0.2.0` reads as a different doc
 
 ### Error codes
 
-`unspellable-link` leaves `ConvertErrorCode`: a `switch` naming it stops compiling, and the link
+`unspellable-character`, `unspellable-line-start` and `unspellable-link` leave `ConvertErrorCode`:
-it named converts.
+a `switch` naming one stops compiling. A document `adfToMarkdown` refused with one of them now
+converts; markdown the parser refused with one of them now refuses with the code the table gives.
 
 | Input | `0.1.0` | `0.2.0` |
 | --- | --- | --- |
 | a link whose `href` or `title` no CommonMark escape spells, on emit | `unspellable-link` | spells `!adf:link[text]{attrs}` |
+| a carriage return in text, on emit | `unspellable-character` | spells `
` |
+| a null character in text, on emit | `unspellable-character` | spells `!adf:text{text="\u0000"}` |
+| a carriage return or null character in a code block, or a null character in a code span, on emit | `unspellable-character` | rides the carry |
+| a paragraph line opening with a code span of three or more backticks, on emit | `unspellable-line-start` | spells the code span |
+| a block directive whose CommonMark spelling holds a carriage return, a null character or a code span opening a line, on parse | `unspellable-character`, `unspellable-line-start` | `unsupported-node-shape`; write the CommonMark spelling |
+| an `emoji`, `mention` or `status` whose `text` holds a line ending or a null character, on emit | `unspellable-whitespace`, `unspellable-character` | rides the inline carry |
+| a text node holding no text, or holding `content`, on emit | `unsupported-node-shape` | rides the carry |
 | a `codeBlock` holding other than plain text nodes, on emit | `unsupported-node-shape` | rides the block carry |
 | a leaf node given a body (`media`, `listBreak`) | `unsupported-node-shape` | `malformed-directive` |
 | a node with a block body written as a leaf (`panel`) | `unsupported-node-shape` | `malformed-directive` |

README.md

@@ -28,13 +28,13 @@ The most useful ADF conversion library available, judged by these goals, in prio
 
 1. **Lossless, and every call returns a result, never a throw.**
 2. **ADF is the hub.**
-3. **Each format reads and writes as its standard says.**
+3. **Easy to find, and clear at a glance what it does.**
-4. **Our markdown is CommonMark, extended only where CommonMark has no spelling.**
+4. **Each format reads and writes as its standard says.**
-5. **No surprises: output reads and edits the way its audience expects.**
+5. **Our markdown is CommonMark, extended only where CommonMark has no spelling.**
-6. **Lossy conversion drops form, never content.**
+6. **No surprises: output reads and edits the way its audience expects.**
-7. **Runs in any JavaScript engine, with no runtime dependencies and nothing to configure or connect.**
+7. **Lossy conversion drops form, never content.**
-8. **Fast, and linear in the document's size.**
+8. **Runs in any JavaScript engine, with no runtime dependencies and nothing to configure or connect.**
-9. **Easy to find, and clear at a glance what it does.**
+9. **Fast, and linear in the document's size as JSON.**
 
 ## Audience
 
@@ -74,7 +74,7 @@ if (result.ok) {
 }
 ```
 
-Serves Goals 1, 2 and 7. Pure functions, each taking a whole document and returning a whole
+Serves Goals 1, 2 and 8. Pure functions, each taking a whole document and returning a whole
 result; no I/O, no configuration. `markdownToHtml` and `htmlToMarkdown` convert through ADF:
 they keep only what ADF holds, and refuse what `markdownToAdf` or `htmlToAdf` refuses.
 
@@ -96,7 +96,7 @@ htmlToMarkdown(html: string): Result<string>              // 0.2.0
 
 ## Plain markdown
 
-Serves Goal 6. Plain markdown is a second flavour of the same grammar. `adfToPlainMarkdown` writes
+Serves Goal 7. Plain markdown is a second flavour of the same grammar. `adfToPlainMarkdown` writes
 markdown other tools render — GitHub, GitLab, Obsidian and the like — keeping the content and
 dropping the rest: attributes, colours, layout, identity. Content is what a reader of the rendered
 document sees or follows: its text, images and link targets. It refuses only
@@ -136,6 +136,7 @@ read replaces mentions, attachments and macros with text.
 - A newline in text is a hard break and in an expand's title a space, edge whitespace outside a
   link or code span is trimmed, carriage returns and null characters are removed, and an empty
   paragraph drops.
+- A text node's `content` drops: Atlassian's schema forbids it, so no rendered document shows it.
 - An ordered list numbered past `999999999`, or adjacent ordered lists whose numbering does not
   continue, is one bullet list keeping its numbers as text.
 - A task list beside a bullet or decision list, or holding a block other than a task, joins one
@@ -180,12 +181,13 @@ Parsing — `markdownToAdf` and `plainMarkdownToAdf`, and `htmlToAdf` at `0.2.0`
 | `unknown-directive-name` | a directive whose name is no node or mark this version spells | check the name in `spec/flavour.md`, or escape the prefix as `\!adf:`; the spelling itself is well formed, so a later minor may give the name meaning |
 | `unmappable-html` | the input holds an HTML construct the documented element set does not map, a comment and a processing instruction among them — at this version that is every raw HTML construct in markdown, the element set landing at `0.2.0` | remove the construct, or write what it holds in the lossless flavour |
 | `unmappable-image` | an image sits inside other content that is not another image's description, or carries a title | give the image a paragraph of its own and drop the title |
+| `unspellable-whitespace` | an `emoji`, `mention` or `status` directive's content slot spells a newline or a carriage return — `&#10;`, `&#13;`, `!adf:text{text="\n"}` | replace it with a space, or write the node as `!adf:carry` — an inline directive never spans lines |
 
 Emitting — `adfToMarkdown`, and `adfToHtml` at `0.2.0`:
 
 | Code | Fires when | What you can do |
 | --- | --- | --- |
-| `not-an-adf-document` | the value handed in is no ADF document — a missing or wrong `type`, a stray key, a node that is not a node | guard the boundary you receive JSON at with `isAdfDocument`; the message names the branch that refused |
+| `not-an-adf-document` | the value handed in is no ADF document — a missing or wrong `type`, a stray key, a node that is not a node, an object in the document holding itself | guard the boundary you receive JSON at with `isAdfDocument`; the message names the branch that refused |
 | `unsupported-document-version` | the document's `version` is not 1 | keep the ADF and pass the document over, or show it read-only; the version is the site's, not yours to change |
 
 Either direction. The emitter's own refusals are in this group — a parse reaches them by asking it
@@ -194,15 +196,12 @@ emit refuses:
 
 | Code | Fires when | What you can do |
 | --- | --- | --- |
-| `unspellable-character` | text or a code block holds a carriage return or a null character, which CommonMark rewrites wherever it sits | strip or replace the character; no escape carries it through the round-trip |
-| `unspellable-line-start` | a paragraph line begins with a code span whose backticks would read back as a code fence | put any text before the code span |
-| `unspellable-whitespace` | an `emoji`, `mention` or `status` holds a newline in the text its inline directive spells in the content slot | replace it with a space — an inline directive never spans lines |
 | `unsupported-nesting-depth` | blocks, marks, an attribute's JSON or a carried node's JSON nest past 500 levels | keep the ADF and pass the document over, or show it read-only; flatten the input where you are the one who wrote it |
-| `unsupported-node-shape` | a node carries an attribute, value, argument or body its type does not take, or lacks one it needs — or markdown writes as a directive a node or mark the lossless flavour spells as CommonMark, or a reserved directive stands out of place: `!adf:textBreak{}` or `!adf:listBreak` parting nothing, `!adf:doc` anywhere but as the whole document | fix what the message names; `spec/flavour.md` lists every type's attributes and body |
+| `unsupported-node-shape` | parsing: markdown spells a node with an attribute, value, argument or body its type does not take, or without one it needs, writes as a directive a node or mark the lossless flavour spells as CommonMark, or puts a reserved directive out of place: `!adf:textBreak{}` or `!adf:listBreak` parting nothing, `!adf:doc` anywhere but as the whole document. Emitting: a node carrying one mark type twice, a block or a non-text inline node holding `text`, or a leaf block or a non-text inline node holding `content` | fix what the message names; `spec/flavour.md` lists every type's attributes and body |
 
 ## The guarantees
 
-Serves Goals 1, 3 and 4.
+Serves Goals 1, 4 and 5.
 
 - `markdownToAdf(adfToMarkdown(doc))` deep-equals `doc` as JSON, for a document of plain objects
   as `JSON.parse` builds them — every key and value as `doc` holds it, adjacent text nodes, an
@@ -217,9 +216,7 @@ Serves Goals 1, 3 and 4.
   `spec/flavour.md`) — and one gap: a CommonMark image fits only as its own title-less paragraph;
   mid-text and titled images are error results, save an image inside another's description, which
   flattens into the alt text. Converting back yields the library's canonical spelling, which
-  round-trips byte-identically — where it converts back at all: a parse succeeding is no promise of
+  round-trips byte-identically.
-  that, so keep the source until the way back succeeds. ``` ` `` ` ``` reads cleanly and then
-  refuses.
 - Four CommonMark spellings parse without an error and build a document the reference
   implementation renders differently: `[](/url)` and `[]()` stay literal text against CommonMark's
   empty link, a list continuing past a marker change stays one list against CommonMark's two, a
@@ -228,18 +225,17 @@ Serves Goals 1, 3 and 4.
   text, which the spec requires and the reference itself breaks, nesting one `<a>` in the other.
   The first three are pinned `pending` in `corpus/commonmark-spec/exceptions.json`; the suite
   holds no example of the fourth.
-- Not every document converts back: `adfToMarkdown` is partial on valid ADF — a text node holding
+- Not every document converts back: `adfToMarkdown` refuses a document nesting past 500 levels, and
-  a carriage return, or a paragraph line beginning with a code span whose backticks read back as a
+  the node shapes the `unsupported-node-shape` row lists. Show the refusal and keep the document
-  fence. Show the refusal and keep the document read-only; saving markdown you could not produce
+  read-only; saving markdown you could not produce is the loss the round-trip exists to stop.
-  is the loss the round-trip exists to stop.
 - The pipe table narrows GFM's twice: every row opens with a pipe, so GFM's bare form is an error
   result rather than the prose it reads as, and an alignment colon in the delimiter row is an
   error too — ADF holds no column alignment. The trailing pipe is canonical output, optional in
   input.
 - Past that and `~~`, no GFM: an autolink literal and a `- [ ]` marker stay text, and a checklist
   is the `taskList` directive — `plainMarkdownToAdf` turns the marker into a `taskList`.
-- A document nested deeper than 500 levels is an error result, not a stack overflow, and no input
+- A document nested deeper than 500 levels is an error result, not a stack overflow, and no call
-  makes a call loop forever.
+  loops forever on a string, or on a value `JSON.parse` or `structuredClone` builds.
 - The emitted formats are semver surface
   ([`docs/decisions.md`](https://gitea.larvit.se/larvit/adf-codec/src/branch/main/docs/decisions.md#the-formats-are-api)).
 - **`0.2.0`** — `htmlToAdf(adfToHtml(doc))` deep-equals `doc`; fidelity HTML cannot express rides
@@ -249,7 +245,7 @@ Serves Goals 1, 3 and 4.
 
 ## The package
 
-Serves Goal 7. ESM only, no runtime dependencies, public npm. Built JavaScript with `.d.ts`
+Serves Goal 8. ESM only, no runtime dependencies, public npm. Built JavaScript with `.d.ts`
 beside it. Pure ECMAScript at an ES2022 baseline, reaching for no host API; the test suite runs
 under Node, Deno and Bun, and a headless Firefox converts the corpus through the built entrypoint.
 Contract: [`docs/decisions.md`](https://gitea.larvit.se/larvit/adf-codec/src/branch/main/docs/decisions.md#any-es2022-engine), §Any

corpus/README.md

@@ -16,7 +16,7 @@ One directory per contract kind:
   is the suite; `refusals.json` pins each refusing example to its error `code`; `exceptions.json`
   pins each known divergence by `check`, `example`, `kind` and the exact `divergence`, with a
   `reason`. `kind` is `mark-model` (the permanent count divergence from ADF's mark-per-text-node
-  model), `unspellable` (parses but the flavour has no spelling) or `pending` (a parser gap).
+  model) or `pending` (a parser gap).
 
 JSON is two-space indent, keys sorted, and a document read back must deep-equal the fixture's
 (`docs/decisions.md` §Equality is deep). `spec.json` is the vendored, upstream machine-readable

corpus/commonmark-spec/exceptions.json

@@ -13,27 +13,6 @@
     "kind": "pending",
     "reason": "A list continuing past a marker change renders as two lists, the parser opens one."
   },
-  {
-    "check": "fixpoint",
-    "divergence": "unspellable-line-start",
-    "example": 330,
-    "kind": "unspellable",
-    "reason": "A paragraph opens with a code span whose backticks read back as a fence."
-  },
-  {
-    "check": "fixpoint",
-    "divergence": "unspellable-line-start",
-    "example": 331,
-    "kind": "unspellable",
-    "reason": "A paragraph opens with a code span whose backticks read back as a fence."
-  },
-  {
-    "check": "fixpoint",
-    "divergence": "unspellable-line-start",
-    "example": 340,
-    "kind": "unspellable",
-    "reason": "A paragraph opens with a code span whose backticks read back as a fence."
-  },
   {
     "check": "count",
     "divergence": "em 2/1",

corpus/round-trip/block-nodes/code-block-carriage-return.json

@@ -0,0 +1,15 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "text": "a\r\nb",
+          "type": "text"
+        }
+      ],
+      "type": "codeBlock"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/block-nodes/code-block-carriage-return.md

@@ -0,0 +1,10 @@
+```adf:codeBlock
+{
+  "content": [
+    {
+      "text": "a\r\nb",
+      "type": "text"
+    }
+  ]
+}
+```

corpus/round-trip/commonmark-subset/code-span-line-start.json

@@ -0,0 +1,20 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "marks": [
+            {
+              "type": "code"
+            }
+          ],
+          "text": "``",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/commonmark-subset/code-span-line-start.md

@@ -0,0 +1 @@
+``` `` ```

corpus/round-trip/inline-nodes/text-carriage-return-null.json

@@ -0,0 +1,43 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "text": "a\r\nb\u0000c",
+          "type": "text"
+        },
+        {
+          "marks": [
+            {
+              "attrs": {
+                "href": "https://example.com/",
+                "title": "t\u0000"
+              },
+              "type": "link"
+            }
+          ],
+          "text": "link",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "attrs": {
+            "color": "neutral",
+            "text": "a\nb"
+          },
+          "type": "status"
+        },
+        {
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/inline-nodes/text-carriage-return-null.md

@@ -0,0 +1,3 @@
+a
!adf:text{text="\n"}b!adf:text{text="\u0000"}c!adf:link[link]{href="https://example.com/" title="t\u0000"}
+
+!adf:carry{json="{\"attrs\":{\"color\":\"neutral\",\"text\":\"a\\nb\"},\"type\":\"status\"}"}!adf:carry{json="{\"type\":\"text\"}"}

docs/decisions.md

@@ -23,13 +23,11 @@ sanitized and a mention keeps the test user's real account id.
 
 ## Markdown in is a canonical fixpoint
 
-2026-08-23, the maintainer. Goals 1 and 4. Valid while markdown input may be written by hand.
+2026-08-23, the maintainer; every parsed document has converted back since 2026-10-04. Goals 1 and
+5. Valid while markdown input may be written by hand.
 
 The other direction is a canonical fixpoint, not byte-identity: human markdown normalizes, the way
-back yields the library's canonical spelling, and that spelling round-trips byte-identically —
+back yields the library's canonical spelling, and that spelling round-trips byte-identically.
-where there is a way back. CommonMark spells some things the flavour has no escape for — a
-paragraph opening with a code span whose backticks read back as a fence — so a parse succeeding
-does not imply a spellable document; `corpus/commonmark-spec/exceptions.json` names those.
 
 ## Equality is deep
 
@@ -56,7 +54,7 @@ around the leaf. The grammar: `spec/flavour.md` §Inline nodes, **Adjacent text
 
 ## An empty key spells `empty`
 
-2026-10-03, a writer panel and the maintainer. Goals 1 and 5. Valid while no attribute value
+2026-10-03, a writer panel and the maintainer. Goals 1 and 6. Valid while no attribute value
 spells an empty object or array.
 
 An `attrs`, `content` or `marks` key holding an empty object or array is the reserved key with the
@@ -73,7 +71,7 @@ reads it back as `-0`. The grammar: `spec/flavour.md` §Block nodes and §The Co
 
 ## Empty markdown is a document of no blocks
 
-2026-10-03, a writer panel and the maintainer. Goals 1 and 5. Valid while ADF's schema requires
+2026-10-03, a writer panel and the maintainer. Goals 1 and 6. Valid while ADF's schema requires
 `content` on `doc`.
 
 Markdown holding no block reads as `{ content: [], type: 'doc', version: 1 }`, the document
@@ -96,7 +94,7 @@ checking its position, and refusing loses a document ADF itself keeps in an `uns
 
 ## The carry fence names the node type
 
-2026-10-03, the maintainer. Goals 1 and 5. Valid while a code fence's info string reads back
+2026-10-03, the maintainer. Goals 1 and 6. Valid while a code fence's info string reads back
 verbatim.
 
 The block carry is a code fence whose info string `adf:<type>` names the node's type, its body the
@@ -120,7 +118,7 @@ language, and none is empty beside another, since a text node holds text. The gr
 
 ## Foreign HTML sorts three ways
 
-2026-08-23, the sort 2026-09-20, the maintainer. Goals 1 and 4. Valid while ADF holds no node
+2026-08-23, the sort 2026-09-20, the maintainer. Goals 1 and 5. Valid while ADF holds no node
 for a bare container, a comment or a script. Lands with `todo.md` item 6.
 
 Every foreign element `htmlToAdf` and `markdownToAdf` read sorts one of three ways, never a silent
@@ -141,14 +139,14 @@ than they buy.
 
 ## Names stay text
 
-2026-08-23, the maintainer. Goal 7. Valid while resolving a name to an id needs I/O.
+2026-08-23, the maintainer. Goal 8. Valid while resolving a name to an id needs I/O.
 
 A bare `@name` or `:smile:` in typed text stays a text node. Only directives produce
 mention/emoji/media nodes; resolving names to ids is the consumer's job.
 
 ## Directives under `!adf:`
 
-2026-08-23, prefixed `!adf:` 2026-09-16, the maintainer. Goals 4 and 5. Valid while prose does not
+2026-08-23, prefixed `!adf:` 2026-09-16, the maintainer. Goals 5 and 6. Valid while prose does not
 write `!adf:`.
 
 Directives are one grammar for everything markdown lacks, namespaced under `!adf:`:
@@ -159,7 +157,7 @@ opener nests by itself and leaf versus container falls out of the node's content
 
 ## CommonMark is a subset
 
-2026-08-23, the maintainer. Goal 4. Valid while prose rarely writes the shapes the carve-outs claim.
+2026-08-23, the maintainer. Goal 5. Valid while prose rarely writes the shapes the carve-outs claim.
 
 Plain CommonMark is a subset, with carve-outs (`spec/flavour.md`): literal text shaped like a
 directive, a pipe table or a `~~` pair is claimed, and so is a code fence whose info string opens
@@ -168,14 +166,14 @@ claims, giving CommonMark its own reader, and `todo.md` item 65 ends the image g
 
 ## Tables
 
-2026-08-23, the maintainer. Goal 5. Valid while a pipe table holds only one header row and inline
+2026-08-23, the maintainer. Goal 6. Valid while a pipe table holds only one header row and inline
 cells.
 
 One header row plus plain inline cells → pipe table; anything richer → directive form.
 
 ## Links
 
-2026-09-13, nesting 2026-09-17, the maintainer. Goals 1 and 5. Valid while CommonMark's link
+2026-09-13, nesting 2026-09-17, the maintainer. Goals 1 and 6. Valid while CommonMark's link
 syntax is what readers edit.
 
 `[text](url "title")`, or `<url>` for a bare autolink-shaped text, wherever CommonMark spells the
@@ -194,7 +192,7 @@ accepted.
 
 ## Plain task ids come from position
 
-2026-09-26, spelling 2026-09-29, the maintainer. Goals 6 and 7. Valid while a site rejects a task
+2026-09-26, spelling 2026-09-29, the maintainer. Goals 7 and 8. Valid while a site rejects a task
 node with no `localId`.
 
 `plainMarkdownToAdf` gives each `taskList`, `taskItem` and `blockTaskItem` lacking one a `localId`
@@ -206,7 +204,7 @@ ids are only skipped.
 
 ## A callout title keeps its link targets
 
-2026-09-29, the maintainer. Goals 5 and 6. Valid while an expand's `title` is a string.
+2026-09-29, the maintainer. Goals 6 and 7. Valid while an expand's `title` is a string.
 
 `plainMarkdownToAdf` writes a link in a folded callout's title as its text and its target in
 parentheses: `> [!faq]- See [x](http://y)` reads to the title `See x (http://y)`. A link whose text
@@ -215,7 +213,7 @@ is its target, with or without `mailto:`, keeps its text alone: `<http://y>` tit
 
 ## The plain flavour's spellings
 
-2026-09-14, panels 2026-09-25 and 2026-09-29, the maintainer. Goals 5 and 6. Valid while GitHub's
+2026-09-14, panels 2026-09-25 and 2026-09-29, the maintainer. Goals 6 and 7. Valid while GitHub's
 renderer is the one the audience's markdown is read in.
 
 README §Plain markdown's rows come from a survey of GitHub, GitLab, Gitea, Obsidian, Pandoc,
@@ -234,7 +232,7 @@ past `[x]`/`[ ]`, and lifting bare URLs, `@name`, `:shortcode:` or ISO dates int
 
 ## The HTML dialect
 
-2026-08-23, the maintainer. Goals 5 and 7. Valid while HTML output is read by consumers styling it
+2026-08-23, the maintainer. Goals 6 and 8. Valid while HTML output is read by consumers styling it
 themselves.
 
 The HTML dialect mirrors the markdown flavour: semantic elements, stable `adf-*` classes, `data-*`
@@ -242,7 +240,7 @@ for what HTML cannot express, text always escaped. No stylesheet ships.
 
 ## No runtime dependencies
 
-2026-08-23, the maintainer. Goal 7. Valid while ~20 lines of own code, or a vendored table, do each
+2026-08-23, the maintainer. Goal 8. Valid while ~20 lines of own code, or a vendored table, do each
 job a dependency would.
 
 `dependencies` is empty. A runtime dependency enters only through an entry here stating why ~20
@@ -252,7 +250,7 @@ and HTML parsers are written in this repo.
 ## Standards ship as data
 
 2026-08-30, the CommonMark suite 2026-09-05 and ADF's schemas 2026-09-13, the maintainer. Goals 1,
-4 and 7. Valid while each table is fixed data a dependency would only wrap.
+5 and 8. Valid while each table is fixed data a dependency would only wrap.
 
 A table a standard fixes is data rather than a dependency: HTML5's 2125 semicolon-terminated
 character references ship packed in their own module, so entity decoding is complete without one.
@@ -275,7 +273,7 @@ nodes that break it.
 
 ## Any ES2022 engine
 
-2026-09-01, the maintainer. Goal 7. Valid while ES2022 is the floor browsers and servers share.
+2026-09-01, the maintainer. Goal 8. Valid while ES2022 is the floor browsers and servers share.
 
 The library runs on any ES2022 engine, not only Node — a browser as readily as a server. The
 shipped source is ECMAScript and nothing else: no host import, no host global, no DOM.
@@ -289,13 +287,13 @@ never the higher one those repo-only tools want.
 
 ## ESM only
 
-2026-08-23, the maintainer. Goal 7. Valid while the audience's toolchains all import ES modules.
+2026-08-23, the maintainer. Goal 8. Valid while the audience's toolchains all import ES modules.
 
 No CommonJS build, no dual-package hazard.
 
 ## One built entrypoint
 
-2026-08-23, the maintainer. Goal 7. Valid while Node refuses to type-strip under `node_modules`.
+2026-08-23, the maintainer. Goal 8. Valid while Node refuses to type-strip under `node_modules`.
 
 Built JavaScript, `.d.ts` beside it. Do not add a TypeScript-source entrypoint — Node refuses to
 type-strip under `node_modules` (`ERR_UNSUPPORTED_NODE_MODULES_TYPE_STRIPPING`), so it cannot serve
@@ -303,7 +301,7 @@ an npm consumer.
 
 ## Public on npm
 
-2026-08-23, the name 2026-09-01, the maintainer. Goals 2 and 7. Valid while the package's source
+2026-08-23, the name 2026-09-01, the maintainer. Goals 2 and 8. Valid while the package's source
 stays public beside it.
 
 Published to public npm as `@larvit/adf-codec`. Public source: the Gitea repo goes public,
@@ -338,8 +336,9 @@ switches on `code` with no `default`.
   `unsupported-node-shape` — since a code no input reaches is one no consumer can switch on
   (2026-09-20).
 - A refusal no spelling recovers from is a gap in the flavour rather than a code: give the flavour
-  the spelling and the code goes (`unspellable-link`, 2026-09-13). A cause the carry answers gets
+  the spelling and the code goes (`unspellable-link`, 2026-09-13; `unspellable-character` and
-  no code: a mark no spelling writes rides the carry with its node.
+  `unspellable-line-start`, 2026-10-04). A cause the carry answers gets no code: a mark no
+  spelling writes rides the carry with its node.
 
 ## Which code a cause takes
 
@@ -348,11 +347,10 @@ handles one cause alike whichever node, attribute or direction raised it.
 
 - A code names the cause; where one cause recurs across node types, across one mark's attributes
   or across directions, one code covers them all and `path` and `message` say which —
-  `unsupported-nesting-depth` is the 500-level guard whichever direction hits it,
+  `unsupported-nesting-depth` is the 500-level guard whichever direction hits it.
-  `unspellable-character` the text node and the code block alike. Where two codes stay apart, the
+  `unspellable-whitespace` is the newline an inline directive's content slot spells in input; the
-  line between them is what they name: `unspellable-character` is a character CommonMark rewrites
+  emitter carries such a node. A null character in that slot is `unsupported-node-shape`, since
-  wherever text holds it, `unspellable-whitespace` the newline no inline directive's content slot
+  `unspellable-whitespace` does not read true of it (2026-10-04).
-  spans, in either direction.
 - A claim code names the spelling claimed, never the node that spelling would have built: a
   malformed `!adf:table` is a `malformed-directive`, and an alignment colon a
   `malformed-pipe-table` — the flavour's own delimiter row is `-` runs, so the grammar refuses the
@@ -377,21 +375,21 @@ handles one cause alike whichever node, attribute or direction raised it.
 
 ## `message` and `path`
 
-2026-09-03, the path 2026-09-23, the maintainer. Goals 1 and 4. Valid while a person fixing the
+2026-09-03, the path 2026-09-23, the maintainer. Goals 1 and 5. Valid while a person fixing the
 input reads `message`.
 
 - A message names the violation, not the rule alone — a rule by itself states a truth the reader
   must invert before it reads as a failure — and where the flavour's claim refuses ordinary prose
   it names the escape that unclaims the form claimed: `\!adf:` for a directive, block line and
   inline alike, `\|` for every pipe row.
-- `not-an-adf-document` carries the document's own path throughout: seven of the guard's eight
+- `not-an-adf-document` carries the document's own path throughout: seven of the guard's nine
-  branches read the document's own shape, and threading a path to the eighth — a malformed node
+  branches read the document's own shape, and threading a path to the other two, which look anywhere
-  anywhere in the tree — wants the manual stack §Nothing recurses unbounded forces. The message
+  in the tree — a malformed node, or an object holding itself — wants the manual stack §Nothing
-  names the violation instead.
+  recurses unbounded forces. The message names the violation instead.
 
 ## Publish on a version bump
 
-2026-08-23, converging 2026-09-03, the maintainer. Goal 7. Valid while CI on `main` holds the npm
+2026-08-23, converging 2026-09-03, the maintainer. Goal 8. Valid while CI on `main` holds the npm
 token.
 
 `package.json` version on `main` is the source of truth. CI on `main`: tests green and the version
@@ -407,7 +405,7 @@ depend on a store that the gate would then have to keep.
 
 ## Docs describe the release being built
 
-2026-09-16, the maintainer. Goal 7. Valid while a bump on `main` publishes.
+2026-09-16, the maintainer. Goal 8. Valid while a bump on `main` publishes.
 
 Docs on `main` describe the release being built rather than the version npm holds, so they match it
 the moment the bump publishes; add no interim note marking the gap.
@@ -423,7 +421,7 @@ nesting a spelling inside its own kind (`*(*a*)*`) names that mark once.
 
 ## The gate runs on Deno and Bun
 
-2026-09-01, Deno's reason 2026-09-28, the maintainer. Goals 3 and 7. Valid while the library claims
+2026-09-01, Deno's reason 2026-09-28, the maintainer. Goals 4 and 8. Valid while the library claims
 any ES2022 engine.
 
 The gate runs the suite under Deno and Bun as well as Node. Bun runs JavaScriptCore, the one engine
@@ -435,7 +433,7 @@ over the corpus rather than over a smoke import.
 
 ## The gate installs the tarball
 
-2026-09-03, the maintainer. Goal 7. Valid while consumers install the packed package.
+2026-09-03, the maintainer. Goal 8. Valid while consumers install the packed package.
 
 The gate packs the build and installs the tarball under `package-tests/`, so `files`, `exports`
 and `types` are proved on the artifact that ships rather than on the source tree a self-reference
@@ -447,7 +445,7 @@ resolver maps them, under `NodeNext` alone; a `.d.ts` reader that is not `tsc` s
 
 ## Firefox reads the build
 
-2026-09-04, the maintainer. Goal 7. Valid while the library claims a browser and no other leg runs
+2026-09-04, the maintainer. Goal 8. Valid while the library claims a browser and no other leg runs
 SpiderMonkey.
 
 A headless Firefox loads `dist/index.js` over HTTP and converts the round-trip, normalization and
@@ -495,16 +493,17 @@ exits 0 on.
 2026-10-03, the maintainer. KISS, a technical principle, and its comprehension floor of 7. Valid
 while `todo.md` items 59, 60, 61 and 62 are open.
 
-A four-seat comprehension panel scored the project under the floor of 7. Its round-5 scores
+A four-seat comprehension panel scored the project under the floor of 7. Its scoring run of
-(2026-10-03) are the baseline. Since 2026-10-04, a chunk whose panel scores any dimension lower
+2026-10-04 is the baseline. Since 2026-10-04, a chunk whose panel scores any dimension lower
 improves what the seats named and scores again, and after three such rounds asks the maintainer.
 
 | Seat | Navigation | Locality | Shape | Self-sufficiency | Overall |
 |---|---|---|---|---|---|
-| Junior | 6 | 5 | 6 | 5 | 5.5 |
+| Junior | 7 | 5.5 | 6.5 | 6 | 6 |
-| Mid | 6.5 | 5 | 6 | 4.5 | 5.5 |
+| Mid | 7 | 5.5 | 6.5 | 6 | 6 |
-| Senior | 6.5 | 5.5 | 6.5 | 5.5 | 6 |
+| Senior | 7 | 5.5 | 6.5 | 5.5 | 6 |
-| Architect | 6.5 | 5.5 | 6 | 6 | 6 |
+| Architect | 7 | 5.5 | 6 | 6 | 6 |
+| Mean | 7.00 | 5.50 | 6.38 | 5.88 | 6.00 |
 
 Three panels on near-identical code scored overall means of 5.88, 5.75 and 5.75, and a seat moves
 ±0.5 between runs.
@@ -518,15 +517,15 @@ markdown, on a fixed seed in the gate; a counterexample found becomes a round-tr
 
 ## The CommonMark suite checks three ways
 
-2026-08-27, the maintainer. Goals 1 and 3. Valid while the suite's answers are HTML ADF cannot be
+2026-08-27, the maintainer. Goals 1 and 4. Valid while the suite's answers are HTML ADF cannot be
 compared against.
 
 Each example is a named error or markdown that parses and emits to itself byte for byte; its
 reference HTML's text, tags stripped and entities decoded, equals the parsed document's; and its
 elements count the marks and nodes they map to. The fixpoint alone passes a parser returning the
 empty document, the text alone one dropping every emphasis. An exception is the maintainer's to
-add, and valid CommonMark parsing to a document `adfToMarkdown` refuses where a spelling could exist
+add, and valid CommonMark parsing to a document `adfToMarkdown` refuses is a bug to fix, never an
-is a bug to fix, never an exception.
+exception.
 
 ## The flavour spec is read as a source
 
@@ -563,6 +562,15 @@ format, as its parser does. A list giving way to the directive form refuses at z
 than walking again; counting every list twice halved the list limit, counting the directive form
 once doubled the parser's frames per level.
 
+## No value `JSON.parse` or `structuredClone` builds loops a call
+
+2026-10-04, the maintainer. Goals 1 and 9. Valid while every persona hands in plain data, as
+`JSON.parse` or `structuredClone` builds it.
+
+The guards walk a value by `Object.values` and refuse a cycle in it. An inherited or non-enumerable
+key, a getter, a Proxy or a custom iterator is the caller's to rule out: no persona builds one.
+Goal 9's size counts ADF as JSON, so a shared object costs once per place it is held.
+
 ## Nothing spreads an unbounded array
 
 2026-09-18, the maintainer. Goal 1. Valid while engines cap a call's arguments.
@@ -581,7 +589,7 @@ termination is the loop's own check.
 
 ## Readers scan by index
 
-2026-08-30, the kept scan 2026-09-18, the maintainer. Goal 8. Valid while the pipeline persona
+2026-08-30, the kept scan 2026-09-18, the maintainer. Goal 9. Valid while the pipeline persona
 feeds documents nobody typed.
 
 A reader takes the text and an index — a sticky regex whose `lastIndex` the caller sets on the line
@@ -593,7 +601,7 @@ two cannot disagree — which is what makes the kept value a memo rather than a
 
 ## The spelling memo
 
-2026-09-19, the maintainer. Goal 8. Valid while the `commonMarkSpelling` ask spells a node once
+2026-09-19, the maintainer. Goal 9. Valid while the `commonMarkSpelling` ask spells a node once
 per level above it otherwise.
 
 The parse and the plain reduction keep each node's readable spelling in a memo, so the
@@ -605,7 +613,7 @@ one. Only what succeeded is kept, so no path minted at another position is ever
 
 ## Cost fixes are measured, never timed
 
-2026-09-18, the maintainer and the stability-reviewer. Goal 8. Valid while Goal 8 promises growth
+2026-09-18, the maintainer and the stability-reviewer. Goal 9. Valid while Goal 9 promises growth
 rather than a figure.
 
 A cost fix that changes no behaviour lands on the suite staying green with no fixture output
@@ -624,7 +632,7 @@ refuses it — which is how the whitespace carry finds a line edge.
 
 ## Emphasis follows CommonMark's matching
 
-2026-08-27, the maintainer. Goals 1 and 3. Valid while CommonMark's emphasis rules are the
+2026-08-27, the maintainer. Goals 1 and 4. Valid while CommonMark's emphasis rules are the
 reader's.
 
 Emphasis is spelled against CommonMark's matching, never flanking alone: a delimiter run in text
@@ -633,7 +641,7 @@ only ones in play, and a pair that matching hands to another delimiter rides the
 
 ## Readable spellings take the `try` prefix
 
-2026-09-21, the maintainer. Goals 1 and 5. Valid while a readable spelling's refusal would cost a
+2026-09-21, the maintainer. Goals 1 and 6. Valid while a readable spelling's refusal would cost a
 document the general form spells.
 
 A readable spelling tried ahead of a general one takes the `try` prefix and fails only where the

spec/flavour.md

@@ -245,7 +245,8 @@ form.
   leaves empty, or in both, is a named error, and so are fences whose info strings differ and an
   empty fence beside another. Each fence is an ordinary code block, and its info string decodes
   escapes and entity references as any other does. A node holding a child no fence holds — any but
-  a text node carrying no marks, `attrs` or `content` — rides the block carry.
+  a text node holding text free of carriage returns and null characters, and carrying no marks,
+  `attrs` or `content` — rides the block carry.
 - `heading` — container, inline body. Attributes: `level` (number), `localId` (string). `level` is
   the `#` count, so a heading carrying none, or one that is no whole number from 1 to 6, has no
   CommonMark spelling.
@@ -449,6 +450,8 @@ the nodes below, `emoji`, `mention` and `status` spell their `text` attribute in
 plain text: `[]` is the empty string, absent content is the absent attribute, non-empty content
 parsing to anything but one text node carrying neither marks, attributes nor content is a named
 error, and so is a `text` key in `{attrs}`. An enclosing mark spelling does not reach into the slot.
+An `emoji`, `mention` or `status` whose `text` attribute holds a line ending or a null character
+rides the inline carry; a content slot spelling one is a named error.
 The rest take no content, `!adf:text` included; content on a node that takes none is a named error.
 
 - `date` — Attributes: `localId` (string), `timestamp` (string, epoch milliseconds).
@@ -471,14 +474,15 @@ The rest take no content, `!adf:text` included; content on a node that takes non
 Shipped !adf:emoji[🎉]{shortName=":tada:"} on !adf:date{timestamp=1756080000000}.
 ```
 
-**Whitespace CommonMark cannot hold.** A newline inside a text node, and a space or tab where
+**Text CommonMark cannot hold plainly.** A carriage return in text is `
`, which CommonMark
-CommonMark strips or refuses one — a block's inline content edges, either side of a line break, an
+reads back as the character. Three things are spelled `!adf:text{text="…"}`: a newline inside a text
-em, strong or strike spelling's inner edges, a pipe cell's edges — is spelled `!adf:text{text="…"}`,
+node; a null character, which CommonMark reads as U+FFFD; and a space or tab where CommonMark strips
-the reserved key carrying the node's text, escaped by the attribute grammar and never literal: pipe
+or refuses one — a block's inline content edges, either side of a line break, an em, strong or
-cells trim and pad. The emitter wraps the whitespace run alone and leaves the rest plain text, which
+strike spelling's inner edges, a pipe cell's edges. The reserved key carries the node's text,
-the spelled run joins on reading. Input reads that spelling alone: the value is one run of spaces
+escaped by the attribute grammar and never literal: pipe cells trim and pad. The emitter wraps the
-and tabs, or one run of newlines, and anything else — a mixed run, or text CommonMark carries
+run alone and leaves the rest plain text, which the spelled run joins on reading. Input reads that
-plainly — is a named error.
+spelling alone: the value is one run of spaces and tabs, one run of newlines, or one run of null
+characters, and anything else — a mixed run, or text CommonMark carries plainly — is a named error.
 
 ```
 !adf:text{text="  "}Two leading spaces held, and one text node split!adf:text{text="\n"}over two lines.
@@ -489,8 +493,8 @@ carried, neither holds `attrs` or an empty key, and their marks are identical, a
 The reserved leaf `!adf:textBreak{}` parts such a pair, inside every mark spelling the two share; a
 code span holds no directive, so it closes and reopens. It builds no node and reads only between
 two such nodes: elsewhere, or with `[content]` or `{attrs}`, it is a named error (`docs/decisions.md`
-§`!adf:textBreak{}` parts text CommonMark would join). A text node holding `attrs` or an empty key
+§`!adf:textBreak{}` parts text CommonMark would join). A text node holding `attrs`, `content` or an
-rides the inline carry.
+empty key, or holding no text, rides the inline carry.
 
 ```
 Hello, !adf:textBreak{}world — **Hello, !adf:textBreak{}world** — `a`!adf:textBreak{}`b`
@@ -531,12 +535,13 @@ breaks at every node the emitter carries, so no emitted carry sits inside a mark
 An inline node whose marks no nesting spells — a mark type not listed here, an attrs key its
 spelling does not list, a value that is not the spelling's type, an attribute the spelling needs and
 the mark lacks, an empty `attrs` on a mark CommonMark spells, an order putting a code span outside
-another mark, `code` over anything but a text node or over text holding a newline, or a spelling
+another mark, `code` over anything but a text node holding text, or over text holding a line ending
-CommonMark's flanking rules cannot open or close where the run sits (`un**-real**istic`), or one
+or a null character, or a spelling CommonMark's flanking rules cannot open or close where the run
-CommonMark's matching pairs elsewhere — the intra-word `*` runs together with a neighbouring `**`,
+sits (`un**-real**istic`), or one CommonMark's matching pairs elsewhere — the intra-word `*` runs
-and the multiple-of-3 rule can leave the merged run's pairing to another delimiter — rides the
+together with a neighbouring `**`, and the multiple-of-3 rule can leave the merged run's pairing to
-inline carry whole. An opaque carry inside a mark spelling is a named error in input: the carry
+another delimiter — rides the inline carry whole. An opaque carry inside a mark spelling is a named
-restores its node exactly, marks included (`docs/decisions.md` §Unknown nodes ride the carry).
+error in input: the carry restores its node exactly, marks included (`docs/decisions.md` §Unknown
+nodes ride the carry).
 
 ```
 !adf:textColor[**Overdue**]{color="#ae2e24"}, H!adf:subsup[2]{type=sub}O, !adf:underline[signed].

src/adf/document.test.ts

@@ -83,18 +83,18 @@ test("reads a node's siblings as a walk rather than as one call's arguments", ()
   assert.equal(fault(wide), 'accepted')
 })
 
-test('refuses a document that holds itself, and accepts one sharing a node or a mark', () => {
+test('refuses an object holding itself, and accepts one shared', () => {
-  const notANode = "an ADF document's content holds ADF nodes: one of them is not"
+  const holdsItself = 'an ADF document is a tree: an object in it holds itself'
   const paragraph: { content: unknown[]; type: string } = { content: [], type: 'paragraph' }
   paragraph.content.push(paragraph)
-  assert.equal(fault({ content: [paragraph], type: 'doc', version: 1 }), notANode)
+  assert.equal(fault({ content: [paragraph], type: 'doc', version: 1 }), holdsItself)
   const document: { content: unknown[]; type: string; version: number } = { content: [], type: 'doc', version: 1 }
   document.content.push(document)
-  assert.equal(fault(document), notANode)
+  assert.equal(fault(document), holdsItself)
   const attrs: Record<string, unknown> = {}
   attrs['a'] = [attrs]
-  assert.equal(fault({ content: [{ attrs, type: 'paragraph' }], type: 'doc', version: 1 }), notANode)
+  assert.equal(fault({ content: [{ attrs, type: 'paragraph' }], type: 'doc', version: 1 }), holdsItself)
-  assert.equal(fault({ content: [{ marks: [{ attrs, type: 'link' }], text: 'x', type: 'text' }], type: 'doc', version: 1 }), notANode)
+  assert.equal(fault({ content: [{ marks: [{ attrs, type: 'link' }], text: 'x', type: 'text' }], type: 'doc', version: 1 }), holdsItself)
   assert.equal(isAdfDocument({ content: [{ attrs, type: 'paragraph' }], type: 'doc', version: 1 }), false)
   const bold = { type: 'strong' }
   const text = { marks: [bold], text: 'x', type: 'text' }

src/adf/document.ts

@@ -1,5 +1,5 @@
 import type { ConvertFault } from '../result.ts'
-import { everyInTree, isJsonValue, overNested, type JsonValue } from '../json-value.ts'
+import { isJsonValue, overNested, type JsonValue } from '../json-value.ts'
 import { largestNesting } from '../nesting.ts'
 import { serializeCanonicalJson } from '../canonical-json.ts'
 
@@ -43,6 +43,7 @@ export function adfDocumentFault(value: unknown): ConvertFault | undefined {
   const held: unknown = value['content']
   if (!Array.isArray(held)) return notADocument(`an ADF document's content is an array: found ${describe(held)}`)
   const content: readonly unknown[] = held
+  if (holdsItself(content)) return notADocument('an ADF document is a tree: an object in it holds itself')
   if (!isNodeArray(content)) return notADocument("an ADF document's content holds ADF nodes: one of them is not")
   return nestingFault(content)
 }
@@ -64,7 +65,7 @@ export function emptyKeys(held: { attrs?: AdfAttributes; content?: AdfNode[]; ma
   return keys
 }
 
-// A format spells this node as text; anything more rides a carry, save content, which is refused.
+// No attrs, content or empty marks; a format may spell this node as text, and anything more rides a carry.
 export function isBareText(node: AdfNode): boolean {
   return node.type === 'text' && node.attrs === undefined && node.content === undefined && node.marks?.length !== 0
 }
@@ -122,17 +123,39 @@ export function nodeMarks(node: { marks?: AdfMark[] }): readonly AdfMark[] {
   return node.marks ?? []
 }
 
+// Tracks ancestors alone: a tree may share an object, but an object holding itself walks the guards forever.
+function holdsItself(root: object): boolean {
+  const pending = [{ depth: 0, item: root }]
+  const ancestors: object[] = []
+  const onPath = new Set<unknown>()
+  while (pending.length > 0) {
+    const entry = pending.pop()
+    if (entry === undefined) continue
+    while (ancestors.length > entry.depth) onPath.delete(ancestors.pop())
+    if (onPath.has(entry.item)) return true
+    ancestors.push(entry.item)
+    onPath.add(entry.item)
+    for (const child of Object.values(entry.item)) if (typeof child === 'object' && child !== null) pending.push({ depth: entry.depth + 1, item: child })
+  }
+  return false
+}
+
 function isNodeArray(value: readonly unknown[]): value is readonly AdfNode[] {
-  return everyInTree(value, (node) => {
+  const pending: unknown[] = [...value]
-    if (!isRecord(node) || !holdsOnly(node, nodeKeys)) return undefined
+  while (pending.length > 0) {
-    if (typeof node['type'] !== 'string') return undefined
+    const node = pending.pop()
-    if ('attrs' in node && !isAttributes(node['attrs'])) return undefined
+    if (!isRecord(node) || !holdsOnly(node, nodeKeys)) return false
-    if ('marks' in node && !isArrayOf(node['marks'], isAdfMark)) return undefined
+    if (typeof node['type'] !== 'string') return false
-    if ('text' in node && typeof node['text'] !== 'string') return undefined
+    if ('attrs' in node && !isAttributes(node['attrs'])) return false
-    if (!('content' in node)) return []
+    if ('marks' in node && !isArrayOf(node['marks'], isAdfMark)) return false
-    const content = node['content']
+    if ('text' in node && typeof node['text'] !== 'string') return false
-    return Array.isArray(content) ? [...content] : undefined
+    if ('content' in node) {
-  })
+      const content = node['content']
+      if (!Array.isArray(content)) return false
+      for (const child of content) pending.push(child)
+    }
+  }
+  return true
 }
 
 function marksKey(marks: readonly AdfMark[]): string {

src/conformance/adf-property.test.ts

@@ -34,11 +34,11 @@ function shownText(nodes: readonly AdfNode[]): string[] {
   return shown.filter((text) => text !== '')
 }
 
-test('a generated document refuses to emit, or its markdown reads back to it', { timeout: propertyTimeout }, () => {
+test('a generated document emits markdown that reads back to it', { timeout: propertyTimeout }, () => {
   fc.assert(
     fc.property(adfDocument, (document) => {
       const emitted = adfToMarkdown(document)
-      if (!emitted.ok) return
+      assert.ok(emitted.ok, emitted.ok ? '' : `${emitted.error.code}: ${emitted.error.message}`)
       const read = markdownToAdf(emitted.value)
       assert.ok(read.ok, read.ok ? '' : `${read.error.code}: ${read.error.message} — reading ${JSON.stringify(emitted.value)}`)
       assert.deepEqual(read.value, document, `reading ${JSON.stringify(emitted.value)}`)

src/conformance/commonmark-spec.test.ts

@@ -13,7 +13,7 @@ const root = join(dirname(fileURLToPath(import.meta.url)), '..', '..', 'corpus',
 const checks = ['count', 'fixpoint', 'text'] as const
 
 type Check = (typeof checks)[number]
-type ExceptionKind = 'mark-model' | 'pending' | 'unspellable'
+type ExceptionKind = 'mark-model' | 'pending'
 
 type SpecExample = { example: number; html: string; markdown: string; section: string }
 
@@ -30,7 +30,7 @@ function isCheck(value: unknown): value is Check {
 }
 
 function isKind(value: unknown): value is ExceptionKind {
-  return value === 'mark-model' || value === 'pending' || value === 'unspellable'
+  return value === 'mark-model' || value === 'pending'
 }
 
 function isSpecExample(value: unknown): value is SpecExample {
@@ -77,12 +77,12 @@ test('the CommonMark spec suite is 0.31.2, vendored byte-exact', () => {
   assert.equal(digest, 'd431b29d97b6f73e69d547109cf5081578fac931e72afe95639ebe766c1b2a20')
 })
 
-test('every exception is unique, names a parsing example, and files a fixpoint only as unspellable', () => {
+test('every exception is unique, names a parsing example, and files no fixpoint divergence', () => {
   assert.equal(exceptionIndex.size, exceptions.length, 'one exception repeats an example and check another holds')
   for (const entry of exceptions) {
     assert.ok(spec.some((candidate) => candidate.example === entry.example), `exception ${entry.example} names no example in the suite`)
     assert.equal(exampleToRefusal.get(entry.example), undefined, `exception ${entry.example} is on the refusal list, not an exception`)
-    if (entry.check === 'fixpoint') assert.equal(entry.kind, 'unspellable', `exception ${entry.example} files a fixpoint divergence as ${entry.kind}; a fixable hole is given the spelling instead`)
+    assert.notEqual(entry.check, 'fixpoint', `exception ${entry.example} files a fixpoint divergence; the emitter spells every document the parser builds`)
   }
 })
 

src/conformance/markdown-property.test.ts

@@ -418,7 +418,7 @@ function holdsDirectiveShape(document: AdfDocument): boolean {
   return false
 }
 
-test('generated markdown refuses, or what it parses to refuses to emit, or its spelling reads back and spells itself', { timeout: propertyTimeout }, () => {
+test('generated markdown refuses, or its spelling reads back and spells itself', { timeout: propertyTimeout }, () => {
   const parameters = propertyRuns(gateRuns)
   let directiveShaped = 0
   let fixpoints = 0
@@ -427,7 +427,7 @@ test('generated markdown refuses, or what it parses to refuses to emit, or its s
       const parsed = markdownToAdf(input)
       if (!parsed.ok) return
       const emitted = adfToMarkdown(parsed.value)
-      if (!emitted.ok) return
+      assert.ok(emitted.ok, emitted.ok ? '' : `${emitted.error.code}: ${emitted.error.message} — spelling ${JSON.stringify(input)}`)
       fixpoints += 1
       if (holdsDirectiveShape(parsed.value)) directiveShaped += 1
       const read = markdownToAdf(emitted.value)

src/conformance/property-harness.ts

@@ -24,7 +24,7 @@ export const propertyTimeout = 600000
 const depthIdentifier = fc.createDepthIdentifier()
 const emptyCell: AdfNode = { content: [{ type: 'paragraph' }], type: 'tableCell' }
 const flatCommonMarkShapeWeight = 4
-export const markdownPieces = fc.constantFrom(...'aZ09 \t\n!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~é\xa0🎉日ー한𠀀', '==', '[!NOTE]', '[x]', 'ab:', 'http://', directivePrefix, `${directivePrefix}a[`, `${directivePrefix}a{`)
+export const markdownPieces = fc.constantFrom(...'aZ09 \t\n\r\0!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~é\xa0🎉日ー한𠀀', '==', '[!NOTE]', '[x]', 'ab:', 'http://', directivePrefix, `${directivePrefix}a[`, `${directivePrefix}a{`)
 const nestingCommonMarkShapeWeight = 21
 const spelledTypes = new Set(['text', ...Object.keys(blockNodes), ...Object.keys(inlineNodes), ...Object.keys(markAttributes)])
 
@@ -106,7 +106,7 @@ const mark: Arbitrary<AdfMark> = occasionallyEmpty(fc.oneof(
 ))
 const marks = fc.uniqueArray(mark, { maxLength: 3, selector: (held) => held.type })
 
-const textNode = occasionallyEmpty(fc.record({ marks, text }).map((held): AdfNode => ({ ...held, type: 'text' })))
+const textNode = occasionallyEmpty(fc.record({ marks, text: fc.oneof({ arbitrary: text, weight: 19 }, { arbitrary: fc.constant(''), weight: 1 }) }).map((held): AdfNode => ({ ...held, type: 'text' })))
 
 const backtickRunNode = fc
   .record({ marks: fc.oneof(fc.constant<AdfMark[]>([]), fc.constant<AdfMark[]>([{ type: 'code' }]), marks), text: fc.string({ maxLength: 6, minLength: 1, unit: fc.constantFrom('`', '``', ' ', 'a') }) })

src/json-value.ts

@@ -2,36 +2,23 @@ import { largestNesting } from './nesting.ts'
 
 export type JsonValue = JsonValue[] | boolean | null | number | string | { [key: string]: JsonValue }
 
-// Tracks ancestors alone: a tree may share an object, but one holding itself would walk forever.
+export function isJsonValue(value: unknown): value is JsonValue {
-export function everyInTree(roots: readonly unknown[], children: (item: unknown) => readonly unknown[] | undefined): boolean {
+  const pending: unknown[] = [value]
-  const pending = Array.from(roots, (item) => ({ depth: 0, item }))
-  const ancestors: unknown[] = []
-  const onPath = new Set<unknown>()
   while (pending.length > 0) {
-    const entry = pending.pop()
+    const item = pending.pop()
-    if (entry === undefined) continue
+    if (item === null || typeof item === 'boolean' || typeof item === 'string') continue
-    while (ancestors.length > entry.depth) onPath.delete(ancestors.pop())
+    if (typeof item === 'number') {
-    if (onPath.has(entry.item)) return false
+      if (!Number.isFinite(item)) return false
-    const held = children(entry.item)
+      continue
-    if (held === undefined) return false
+    }
-    if (held.length === 0) continue
+    // A hole is not a JSON value, and Array.prototype methods skip holes — spreading materialises them.
-    ancestors.push(entry.item)
+    if (Array.isArray(item)) for (const child of [...item]) pending.push(child)
-    onPath.add(entry.item)
+    else if (typeof item === 'object') for (const child of Object.values(item)) pending.push(child)
-    for (const child of held) pending.push({ depth: entry.depth + 1, item: child })
+    else return false
   }
   return true
 }
 
-export function isJsonValue(value: unknown): value is JsonValue {
-  return everyInTree([value], (item) => {
-    if (item === null || typeof item === 'boolean' || typeof item === 'string') return []
-    if (typeof item === 'number') return Number.isFinite(item) ? [] : undefined
-    // A hole is not a JSON value, and Array.prototype methods skip holes — spreading materialises them.
-    if (Array.isArray(item)) return [...item]
-    return typeof item === 'object' ? Object.values(item) : undefined
-  })
-}
-
 export function nestingDepth(value: unknown): number {
   const pending: { depth: number; item: unknown }[] = [{ depth: 0, item: value }]
   let deepest = 0

src/markdown/commonmark/grammar.ts

@@ -83,10 +83,6 @@ export function backslashEscape(text: string, index: number): string | undefined
   return isAsciiPunctuation(escaped) ? escaped : undefined
 }
 
-export function claimsLine(line: string, position: LinePosition): boolean {
-  return escapesLineClaim(line, 0, position) || orderedListOpener.test(line)
-}
-
 export function claimsPipeLine(line: string): boolean {
   return pipeClaim.test(line)
 }

src/markdown/commonmark/link-syntax.ts

@@ -1,4 +1,4 @@
-import { backslashEscape, decodeTextEscapes, holdsControlCharacter } from './grammar.ts'
+import { backslashEscape, decodeTextEscapes, holdsControlCharacter, holdsNullCharacter } from './grammar.ts'
 import { holdsEntityReference } from './entity-references.ts'
 
 export type LinkDefinition = { destination: string; title?: string }
@@ -117,5 +117,5 @@ export function escapeUnbalanced(spelling: string, opener: string, closer: strin
 }
 
 function spellTitle(title: string): string | undefined {
-  return /[\n\r\\]/.test(title) || holdsEntityReference(title) ? undefined : ` "${title.replaceAll('"', '\\"')}"`
+  return /[\n\r\\]/.test(title) || holdsNullCharacter(title) || holdsEntityReference(title) ? undefined : ` "${title.replaceAll('"', '\\"')}"`
 }

src/markdown/directive-syntax.ts

@@ -1,7 +1,7 @@
 import type { AttributeKind, VocabularyPair, VocabularyValue } from '../adf/attribute-vocabulary.ts'
 import type { ConvertFault } from '../result.ts'
 import type { JsonValue } from '../json-value.ts'
-import { backslashEscape } from './commonmark/grammar.ts'
+import { backslashEscape, holdsNullCharacter } from './commonmark/grammar.ts'
 import { backtickRun, closingBacktickRun } from './commonmark/backtick-runs.ts'
 import { isJsonValue, overNested } from '../json-value.ts'
 import { largestNesting } from '../nesting.ts'
@@ -100,10 +100,10 @@ export function readSoleStringAttribute(span: DirectiveSpan, key: string): Read<
   return { value: spelled.decoded }
 }
 
-// Both directions answer alike: an inline directive never spans lines, so no content slot holds a line ending.
+// An inline directive never spans lines, and no content slot holds a null character; the emitter carries such a node.
-export function slotLineEndingFault(type: string, text: string): ConvertFault | undefined {
+export function slotFault(type: string, text: string): ConvertFault | undefined {
-  if (!/[\n\r]/.test(text)) return undefined
+  if (/[\n\r]/.test(text)) return { code: 'unspellable-whitespace', message: `the ${type} content slot holds a newline no inline directive spans` }
-  return { code: 'unspellable-whitespace', message: `the ${type} content slot holds a newline no inline directive spans` }
+  return holdsNullCharacter(text) ? unsupportedNodeShape(`the ${type} content slot holds a null character: write the node as !adf:carry`) : undefined
 }
 
 export function spellAttributes(pairs: readonly (readonly [string, string])[]): string {

src/markdown/emit/adf-to-markdown.test.ts

@@ -35,7 +35,7 @@ test('names the node a refusal came from, and no source the emitter never read',
   const unspellable: AdfNode = { text: 'x', type: 'paragraph' }
   const list: AdfNode = { content: [{ content: [paragraph({ text: 'x', type: 'text' })], type: 'listItem' }, { content: [unspellable], type: 'listItem' }], type: 'bulletList' }
   assert.deepEqual(path(adfToMarkdown(document(paragraph({ text: 'x', type: 'text' }), list))), ['content', 1, 'content', 1, 'content', 0])
-  assert.deepEqual(path(adfToMarkdown(document(paragraph({ text: 'x', type: 'text' }, { type: 'text' })))), ['content', 0, 'content', 1])
+  assert.deepEqual(path(adfToMarkdown(document(paragraph({ text: 'x', type: 'text' }, { text: 'x', type: 'status' })))), ['content', 0, 'content', 1])
   assert.deepEqual(path(adfToMarkdown({ type: 'doc', version: 2 })), [])
   assert.equal(position(adfToMarkdown(document(paragraph({ text: 'x', type: 'text' }), list))), undefined)
 })
@@ -147,8 +147,16 @@ test('carries a mark the canonical spellings cannot nest', () => {
   )
 })
 
-test('refuses a line whose start block parsing would claim', () => {
+function readsBack(doc: AdfDocument): string {
-  assert.equal(code(adfToMarkdown(document(paragraph({ marks: [{ type: 'code' }], text: '```', type: 'text' })))), 'unspellable-line-start')
+  const spelled = markdown(adfToMarkdown(doc))
+  assert.deepEqual(markdownToAdf(spelled), { ok: true, value: doc }, `reading ${JSON.stringify(spelled)}`)
+  return spelled
+}
+
+test('spells a code span opening a line, whose backticks open no fence', () => {
+  const fence: AdfNode = { marks: [{ type: 'code' }], text: '``', type: 'text' }
+  assert.equal(readsBack(document(paragraph(fence))), '``` `` ```\n')
+  assert.equal(readsBack(document(paragraph({ text: 'a', type: 'text' }, { type: 'hardBreak' }, fence))), 'a\\\n``` `` ```\n')
 })
 
 test('escapes the delimiter row a hard break leaves opening a pipe table with no leading pipe', () => {
@@ -456,28 +464,26 @@ test('spells a list item whose marker completes a thematic break as a directive'
   )
 })
 
-test('refuses the characters CommonMark rewrites', () => {
+test('spells the characters CommonMark rewrites', () => {
-  assert.equal(
+  assert.equal(readsBack(document(paragraph({ text: 'a\r\r\nb', type: 'text' }))), 'a

!adf:text{text="\\n"}b\n')
-    markdown(adfToMarkdown(document({ content: [{ text: 'a\rb', type: 'text' }], type: 'codeBlock' }))),
+  assert.equal(readsBack(document(paragraph({ marks: [{ type: 'strong' }], text: '\u0000\u0000a\u0000', type: 'text' }))), '**!adf:text{text="\\u0000\\u0000"}a!adf:text{text="\\u0000"}**\n')
-    'unspellable-character: a codeBlock holds no carriage return CommonMark keeps: this text holds one',
+  assert.equal(readsBack(document(paragraph({ marks: [{ attrs: { href: 'u' }, type: 'link' }], text: 'a\rb\u0000', type: 'text' }))), '[a
b!adf:text{text="\\u0000"}](u)\n')
-  )
+  assert.equal(readsBack(document({ attrs: { level: 1 }, content: [{ text: '\r', type: 'text' }], type: 'heading' })), '# 
\n')
-  assert.equal(
+  assert.equal(readsBack(document({ content: [{ text: 'a\rb', type: 'text' }], type: 'codeBlock' })), '```adf:codeBlock\n{\n  "content": [\n    {\n      "text": "a\\rb",\n      "type": "text"\n    }\n  ]\n}\n```\n')
-    markdown(adfToMarkdown(document(paragraph({ text: 'a\rb', type: 'text' })))),
+  readsBack(document({ content: [{ text: 'a\u0000b', type: 'text' }], type: 'codeBlock' }))
-    'unspellable-character: a text node holds a carriage return CommonMark rewrites',
+  readsBack(document(paragraph({ marks: [{ type: 'code' }], text: 'a\u0000b', type: 'text' })))
-  )
-  assert.equal(code(adfToMarkdown(document(paragraph({ text: 'a\u0000b', type: 'text' })))), 'unspellable-character')
-  assert.equal(code(adfToMarkdown(document({ content: [{ text: 'a\u0000b', type: 'text' }], type: 'codeBlock' }))), 'unspellable-character')
-  assert.equal(markdown(adfToMarkdown(document({ content: [{ text: '', type: 'text' }], type: 'codeBlock' }))), 'unsupported-node-shape: a text node holds text: this one has none')
 })
 
-test('refuses a text node the spelling would empty out', () => {
+test('carries a text node holding no text, or holding content', () => {
   const nested: AdfNode[] = [{ text: 'lost', type: 'text' }]
-  const empty = 'unsupported-node-shape: a text node holds text: this one has none'
+  assert.equal(readsBack(document(paragraph({ text: '', type: 'text' }))), '!adf:carry{json="{\\"text\\":\\"\\",\\"type\\":\\"text\\"}"}\n')
-  const holding = 'unsupported-node-shape: a text node holds no content: this one holds some'
+  assert.equal(readsBack(document(paragraph({ type: 'text' }, { text: 'a', type: 'text' }))), '!adf:carry{json="{\\"type\\":\\"text\\"}"}a\n')
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ text: '', type: 'text' })))), empty)
+  readsBack(document(paragraph({ marks: [{ type: 'code' }], text: '', type: 'text' })))
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ marks: [{ type: 'code' }], text: '', type: 'text' })))), empty)
+  readsBack(document(paragraph({ marks: [{ type: 'em' }], text: 'a', type: 'text' }, { marks: [{ type: 'em' }], text: '', type: 'text' })))
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ content: nested, text: 'x', type: 'text' })))), holding)
+  readsBack(document(paragraph({ content: nested, text: 'x', type: 'text' })))
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ content: nested, marks: [{ type: 'code' }], text: 'x', type: 'text' })))), holding)
+  readsBack(document(paragraph({ content: nested, marks: [{ type: 'code' }], text: 'x', type: 'text' })))
+  readsBack(document({ content: [{ text: '', type: 'text' }], type: 'codeBlock' }))
+  readsBack(document({ content: [{ text: 'a', type: 'text' }, { type: 'text' }], type: 'codeBlock' }))
 })
 
 test('carries a mark run whose edge holds whitespace CommonMark flanking counts', () => {
@@ -688,8 +694,12 @@ test('refuses the content and slot an inline directive has no room for', () => {
   assert.equal(refused({ text: 'x', type: 'status' }), neither('status', 'text'))
   assert.equal(refused({ content: [{ text: 'x', type: 'text' }], type: 'hardBreak' }), neither('hardBreak', 'content'))
   assert.equal(refused({ text: 'x', type: 'hardBreak' }), neither('hardBreak', 'text'))
-  assert.equal(refused({ attrs: { text: 'a\nb' }, type: 'status' }), 'unspellable-whitespace: the status content slot holds a newline no inline directive spans')
+})
-  assert.equal(refused({ attrs: { text: 'a\u0000b' }, type: 'status' }), 'unspellable-character: a status content slot holds a null character CommonMark replaces')
+
+test('carries an inline node whose content slot holds a line ending or a null character', () => {
+  assert.equal(readsBack(document(paragraph({ attrs: { text: 'a\nb' }, type: 'status' }))), '!adf:carry{json="{\\"attrs\\":{\\"text\\":\\"a\\\\nb\\"},\\"type\\":\\"status\\"}"}\n')
+  readsBack(document(paragraph({ attrs: { text: 'a\rb' }, type: 'emoji' })))
+  readsBack(document(paragraph({ attrs: { id: 'x', text: 'a\u0000b' }, type: 'mention' })))
 })
 
 test('spells the directive marks around the longest run they cover', () => {

src/markdown/emit/adf-to-markdown.ts

@@ -128,9 +128,9 @@ function spellReadableBlock(node: AdfNode, path: ConvertErrorPath, depth: number
   if (plain !== undefined) return plain
   if (node.type === 'blockquote') return tryBlockquote(node, path, depth, writing)
   if (node.type === 'bulletList' || node.type === 'orderedList') return tryList(node, path, depth, writing)
-  if (node.type === 'codeBlock') return tryCodeBlock(node, path)
+  if (node.type === 'codeBlock') return readableText(tryCodeBlock(node))
   if (node.type === 'heading') return tryHeading(node, path, writing.flavour)
-  if (node.type === 'mediaSingle') return readableText(tryImage(node, path))
+  if (node.type === 'mediaSingle') return readableText(tryImage(node))
   if (node.type === 'paragraph') return tryParagraph(node, path, writing.flavour)
   if (node.type === 'rule') return readableText(tryRule(node))
   if (node.type === 'table') return readableText(tryPipeTable(node, path, writing.flavour))
@@ -251,43 +251,36 @@ function tryBlockquote(node: AdfNode, path: ConvertErrorPath, depth: number, wri
   return success(commonMarkText(quoted(alert ? `\\${text}` : text), inner.value.headroom))
 }
 
-function tryCodeBlock(node: AdfNode, path: ConvertErrorPath): Result<EmittedBlock> | undefined {
+function tryCodeBlock(node: AdfNode): string | undefined {
   if (!holdsOnlyAttributes(node, ['language'])) return undefined
   const slot = languageSlot(nodeAttrs(node)['language'])
   if (slot.kind === 'attribute') return undefined
-  const texts = fencedTexts(node, path)
+  const [only, ...others] = fencedTexts(node) ?? []
-  if (!texts.ok) return texts
-  const [only, ...others] = texts.value ?? []
   if (only === undefined || others.length > 0) return undefined
-  return success(commonMarkText(fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', only)))
+  return fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', only)
 }
 
 // spec/flavour.md, The CommonMark blocks: one fence per text node, the language on each; with no fence to carry it, the attribute does.
 function emitCodeDirective(node: AdfNode, model: BlockNodeModel, path: ConvertErrorPath, depth: number): Result<EmittedBlock> {
-  const texts = fencedTexts(node, path)
+  const texts = fencedTexts(node)
-  if (!texts.ok) return texts
+  if (texts === undefined) return commonMarkLine(carriedBlock(node, path, depth))
-  if (texts.value === undefined) return commonMarkLine(carriedBlock(node, path, depth))
+  const slot: LanguageSlot = texts.length === 0 ? { kind: 'attribute' } : languageSlot(nodeAttrs(node)['language'])
-  const slot: LanguageSlot = texts.value.length === 0 ? { kind: 'attribute' } : languageSlot(nodeAttrs(node)['language'])
   const opener = spellBlockDirectiveOpener(node, model, path, slot.kind === 'attribute' ? [] : ['language'])
   if (opener === undefined) return commonMarkLine(carriedBlock(node, path, depth))
   if (!opener.ok) return opener
   const info = slot.kind === 'fence' ? slot.info : ''
-  return success(directivePair(node, opener.value, texts.value.map((text) => fencedCodeBlock(info, text)).join('\n')))
+  return success(directivePair(node, opener.value, texts.map((text) => fencedCodeBlock(info, text)).join('\n')))
 }
 
-// The text each fence holds, or `undefined` where a child is no plain text node, which the carry holds instead.
+// The text of each fence, or `undefined` where a child holds what no fence keeps, so the block carry takes the node.
-function fencedTexts(node: AdfNode, path: ConvertErrorPath): Result<string[] | undefined> {
+function fencedTexts(node: AdfNode): string[] | undefined {
-  if (node.content === undefined) return success([''])
+  if (node.content === undefined) return ['']
-  if (node.content.some((child) => !isUnmarkedBareText(child))) return success(undefined)
   const texts: string[] = []
-  for (const [index, child] of node.content.entries()) {
+  for (const child of node.content) {
-    const childPath = [...path, 'content', index]
+    if (!isUnmarkedBareText(child) || typeof child.text !== 'string' || child.text === '' || /\r/.test(child.text) || holdsNullCharacter(child.text)) return undefined
-    if (typeof child.text !== 'string' || child.text === '') return failure('unsupported-node-shape', 'a text node holds text: this one has none', childPath)
-    if (/\r/.test(child.text)) return failure('unspellable-character', 'a codeBlock holds no carriage return CommonMark keeps: this text holds one', childPath)
-    if (holdsNullCharacter(child.text)) return failure('unspellable-character', 'a codeBlock holds a null character CommonMark replaces', childPath)
     texts.push(child.text)
   }
-  return success(texts)
+  return texts
 }
 
 function tryHeading(node: AdfNode, path: ConvertErrorPath, flavour: Flavour): Result<EmittedBlock> | undefined {

src/markdown/emit/image.ts

@@ -1,5 +1,4 @@
 import type { AdfNode } from '../../adf/document.ts'
-import type { ConvertErrorPath } from '../../result.ts'
 import { holdsOnlyAttributes, nodeAttrs, nodeContent } from '../../adf/document.ts'
 import { serializeCanonicalJson } from '../../canonical-json.ts'
 import { tryImageLine } from './inline-line.ts'
@@ -7,10 +6,10 @@ import { tryImageLine } from './inline-line.ts'
 const centeredMediaSingle = '{"layout":"center"}'
 const imageAttributes = ['alt', 'type', 'url']
 
-export function tryImage(node: AdfNode, path: ConvertErrorPath): string | undefined {
+export function tryImage(node: AdfNode): string | undefined {
   const image = imageShape(node)
   if (image === undefined) return undefined
-  return tryImageLine(image.alt, image.url, [...path, 'content', 0])
+  return tryImageLine(image.alt, image.url)
 }
 
 function imageShape(node: AdfNode): { alt: string | undefined; url: string } | undefined {

src/markdown/emit/inline-line.ts

@@ -4,17 +4,17 @@ import type { InlineNodeModel } from '../../adf/inline-nodes.ts'
 import type { LineContainer } from '../line-container.ts'
 import { assembleInlineLine, isSyntax, type InlineEscaping, type InlineSegment, type MarkRun, type NodeRange } from './line-escaping.ts'
 import { carriedInline } from '../opaque-carry.ts'
-import { claimsLine, holdsNullCharacter, trimTrailingSpace } from '../commonmark/grammar.ts'
+import { holdsNullCharacter, trimTrailingSpace } from '../commonmark/grammar.ts'
 import { commonMarkLink, linkHref, markSpelling, spellMarkAttributes } from '../mark-spellings.ts'
-import { identicalMark, isBareText, nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
 import { escapeUnbalanced, spellDestination } from '../commonmark/link-syntax.ts'
-import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
+import { identicalMark, isBareText, nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
+import { failure, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { highlightDelimiter } from '../plain/conventions.ts'
 import { inlineNodeModel } from '../../adf/inline-nodes.ts'
 import { joinsWhenRead, textBreakSpelling } from '../adjacent-text.ts'
 import { largestNesting } from '../../nesting.ts'
 import { longestBacktickRun } from '../commonmark/backtick-runs.ts'
-import { slotLineEndingFault, spellInlineDirectiveOpener, spellInlineLeafDirective } from '../directive-syntax.ts'
+import { slotFault, spellInlineDirectiveOpener, spellInlineLeafDirective } from '../directive-syntax.ts'
 import { spellInlineNodeAttributes } from './inline-directive-spelling.ts'
 import { spellTextDirective } from '../text-directive.ts'
 
@@ -38,7 +38,7 @@ type LineAttempt = { fallback: NodeRange | 'opening-link'; line?: undefined } |
 
 type LineFallbacks = { carried: Set<number>; flavour: Flavour; openingLinkAsDirective: boolean }
 
-export type PlainLineFallback = { kind: 'claimed-line'; line: number; text: string } | { kind: 'opening-link' } | { kind: 'unspellable-run'; runs: [MarkRun, ...MarkRun[]] }
+export type PlainLineFallback = { kind: 'opening-link' } | { kind: 'unspellable-run'; runs: [MarkRun, ...MarkRun[]] }
 
 export function emitInlineLine(nodes: readonly AdfNode[], container: LineContainer, path: ConvertErrorPath, flavour: Flavour): Result<string> {
   const emitted = emitLine(nodes, container, path, flavour)
@@ -67,13 +67,12 @@ export function tryPipeCell(nodes: readonly AdfNode[], path: ConvertErrorPath, f
   return emitted.value.line
 }
 
-export function tryImageLine(alt: string | undefined, href: string, path: ConvertErrorPath): string | undefined {
+export function tryImageLine(alt: string | undefined, href: string): string | undefined {
   if (alt !== undefined && (/^[ \t]|[ \t]$|[\n\r]/.test(alt) || holdsNullCharacter(alt))) return undefined
   const destination = spellDestination(href)
   if (destination === undefined) return undefined
   const description: InlineSegment[] = alt === undefined ? [] : [{ escaping: 'bracketed', text: alt }]
-  const attempt = attemptLine([syntax('!['), ...description, syntax(`](${destination})`)], 'paragraph', path, 'lossless')
+  return attemptLine([syntax('!['), ...description, syntax(`](${destination})`)], 'paragraph', 'lossless').line
-  return attempt.ok ? attempt.value.line : undefined
 }
 
 function emitLine(nodes: readonly AdfNode[], container: LineContainer, path: ConvertErrorPath, flavour: Flavour): Result<EmittedLine> {
@@ -87,12 +86,11 @@ function emitLine(nodes: readonly AdfNode[], container: LineContainer, path: Con
       if (!taken.ok) return taken
       continue
     }
-    const attempt = attemptLine(emission.value.segments, container, path, flavour)
+    const attempt = attemptLine(emission.value.segments, container, flavour)
-    if (!attempt.ok) return attempt
+    if (attempt.line !== undefined) {
-    if (attempt.value.line !== undefined) {
+      return success({ line: attempt.line, openingLinkAsDirective: fallbacks.openingLinkAsDirective, segments: emission.value.segments })
-      return success({ line: attempt.value.line, openingLinkAsDirective: fallbacks.openingLinkAsDirective, segments: emission.value.segments })
     }
-    const taken = takeFallback(fallbacks, attempt.value.fallback, path)
+    const taken = takeFallback(fallbacks, attempt.fallback, path)
     if (!taken.ok) return taken
   }
 }
@@ -117,12 +115,11 @@ function lineSegments(nodes: readonly AdfNode[], container: LineContainer, path:
   return success({ segments: spellEdgeWhitespace(emission.value.segments) })
 }
 
-function attemptLine(segments: readonly InlineSegment[], container: LineContainer, path: ConvertErrorPath, flavour: Flavour): Result<LineAttempt> {
+function attemptLine(segments: readonly InlineSegment[], container: LineContainer, flavour: Flavour): LineAttempt {
   const verdict = lineVerdict(segments, container, flavour)
-  if (verdict.kind === 'opening-link') return success({ fallback: 'opening-link' })
+  if (verdict.kind === 'opening-link') return { fallback: 'opening-link' }
-  if (verdict.kind === 'unspellable-run') return success({ fallback: verdict.runs[0] })
+  if (verdict.kind === 'unspellable-run') return { fallback: verdict.runs[0] }
-  if (verdict.kind === 'claimed-line') return failure('unspellable-line-start', `block parsing would claim the emitted line ${JSON.stringify(verdict.text)}`, path)
+  return { line: verdict.text }
-  return success({ line: verdict.text })
 }
 
 // The fallbacks in the order a line takes them, or the line where it takes none.
@@ -130,10 +127,7 @@ function lineVerdict(segments: readonly InlineSegment[], container: LineContaine
   const assembled = assembleInlineLine(segments, container, flavour)
   if (assembled.openingLinkAsDirective) return { kind: 'opening-link' }
   const [run, ...others] = assembled.unspellableRuns
-  if (run !== undefined) return { kind: 'unspellable-run', runs: [run, ...others] }
+  return run === undefined ? { kind: 'line', text: assembled.line } : { kind: 'unspellable-run', runs: [run, ...others] }
-  const lines = assembled.line.split('\n')
-  const claimed = container === 'paragraph' ? lines.findIndex((single, index) => claimsLine(single, index === 0 ? 'first' : 'later')) : -1
-  return claimed === -1 ? { kind: 'line', text: assembled.line } : { kind: 'claimed-line', line: claimed, text: lines[claimed] ?? '' }
 }
 
 // spec/flavour.md, Inline nodes.
@@ -223,9 +217,14 @@ function nodePath(context: InlineContext, index: number): ConvertErrorPath {
   return [...context.path, 'content', index]
 }
 
+// Decides the text-node and slot-fault carries up front, so a line holding many of them is emitted once.
 function carries(node: AdfNode, carried: ReadonlySet<number>, index: number): boolean {
   if (carried.has(index)) return true
-  return node.type !== 'text' && inlineNodeModel(node.type) === undefined
+  if (node.type === 'text') return !isBareText(node) || typeof node.text !== 'string' || node.text === ''
+  const model = inlineNodeModel(node.type)
+  if (model === undefined) return true
+  const slot = model.textAttribute === undefined ? undefined : nodeAttrs(node)[model.textAttribute]
+  return typeof slot === 'string' && slotFault(node.type, slot) !== undefined && nodeContent(node).length === 0 && node.text === undefined
 }
 
 function emitLeaf(node: AdfNode, context: InlineContext, index: number): Result<Emission> {
@@ -238,7 +237,7 @@ function emitLeaf(node: AdfNode, context: InlineContext, index: number): Result<
   const types = nodeMarks(node).map((mark) => mark.type)
   if (new Set(types).size !== types.length) return failure('unsupported-node-shape', `a ${node.type} node carries one mark type twice`, path)
   const model = inlineNodeModel(node.type)
-  if (model === undefined) return emitText(node, context, index, path)
+  if (model === undefined) return success(emitText(node, context, index))
   if (node.type === 'hardBreak') return emitHardBreak(node, model, context, index, path)
   return emitInlineDirective(node, model, index, path)
 }
@@ -259,39 +258,27 @@ function emitInlineDirective(node: AdfNode, model: InlineNodeModel, index: numbe
   if (attributes === undefined) return success({ carry: { first: index, last: index } })
   const slot = model.textAttribute === undefined ? undefined : nodeAttrs(node)[model.textAttribute]
   if (slot === undefined) return success({ segments: [syntax(spellInlineLeafDirective(node.type, attributes))] })
-  if (typeof slot !== 'string') return success({ carry: { first: index, last: index } })
+  if (typeof slot !== 'string' || slotFault(node.type, slot) !== undefined) return success({ carry: { first: index, last: index } })
-  const spans = slotLineEndingFault(node.type, slot)
-  if (spans !== undefined) return faulted(spans, path)
-  if (holdsNullCharacter(slot)) return failure('unspellable-character', `a ${node.type} content slot holds a null character CommonMark replaces`, path)
   const content: InlineSegment[] = slot === '' ? [] : [{ escaping: 'bracketed', text: slot }]
   return success({ segments: [syntax(spellInlineDirectiveOpener(node.type)), ...content, syntax(`]${attributes}`)] })
 }
 
-function textHoldingContent(node: AdfNode, path: ConvertErrorPath): Result<never> | undefined {
+// spec/flavour.md, Text CommonMark cannot hold plainly.
-  return node.type === 'text' && nodeContent(node).length > 0 ? failure('unsupported-node-shape', 'a text node holds no content: this one holds some', path) : undefined
+function emitText(node: AdfNode, context: InlineContext, index: number): Emission {
-}
+  if (!isBareText(node) || typeof node.text !== 'string' || node.text === '') return { carry: { first: index, last: index } }
-
-function emitText(node: AdfNode, context: InlineContext, index: number, path: ConvertErrorPath): Result<Emission> {
-  const holding = textHoldingContent(node, path)
-  if (holding !== undefined) return holding
-  if (!isBareText(node)) return success({ carry: { first: index, last: index } })
-  if (typeof node.text !== 'string' || node.text === '') return failure('unsupported-node-shape', 'a text node holds text: this one has none', path)
-  if (/\r/.test(node.text)) return failure('unspellable-character', 'a text node holds a carriage return CommonMark rewrites', path)
-  if (holdsNullCharacter(node.text)) return failure('unspellable-character', 'a text node holds a null character CommonMark replaces', path)
   const escaping: InlineEscaping = context.bracketed ? 'bracketed' : 'backslash'
-  const parts = node.text.split(/(\n+)/).filter((part) => part !== '')
+  const parts = node.text.split(/(\n+|\0+|\r)/).filter((part) => part !== '')
-  return success({ segments: parts.map((part) => (part.startsWith('\n') ? textDirectiveSegment(part) : { escaping, text: part })) })
+  return { segments: parts.map((part) => (part === '\r' ? syntax('&#13;') : /^[\n\0]/.test(part) ? textDirectiveSegment(part) : { escaping, text: part })) }
 }
 
 function emitMarkedRun(nodes: readonly AdfNode[], mark: AdfMark, depth: number, index: number, context: InlineContext): Result<Emission> {
-  const path = nodePath(context, index)
   const range: NodeRange = { first: index, last: index + nodes.length - 1 }
   if (mark.type === 'backgroundColor' && context.flavour === 'plain') return emitHighlight(nodes, depth, range, context)
   const spelling = markSpelling(mark.type)
   if (spelling === undefined) return success({ carry: range })
   const attributes = spellMarkAttributes(mark, spelling)
   if (attributes === undefined) return success({ carry: range })
-  if (spelling.kind === 'code') return emitCodeSpan(nodes, depth, range, path)
+  if (spelling.kind === 'code') return success(emitCodeSpan(nodes, depth, range))
   if (spelling.kind === 'emphasis') return emitEmphasis(nodes, spelling.spelling, depth, range, context)
   const link = spelling.kind === 'link' ? tryLink(nodes, mark, depth, range, context) : undefined
   if (link !== undefined) return link
@@ -325,20 +312,15 @@ function emitHighlight(nodes: readonly AdfNode[], depth: number, range: NodeRang
 }
 
 // Each node its own span: CommonMark reads two adjacent text nodes in one span back as one.
-function emitCodeSpan(nodes: readonly AdfNode[], depth: number, range: NodeRange, path: ConvertErrorPath): Result<Emission> {
+function emitCodeSpan(nodes: readonly AdfNode[], depth: number, range: NodeRange): Emission {
   const spans: string[] = []
   for (const node of nodes) {
-    const holding = textHoldingContent(node, path)
-    if (holding !== undefined) return holding
-    if (!isBareText(node) || nodeMarks(node).length !== depth + 1) return success({ carry: range })
     const { text } = node
-    if (typeof text !== 'string' || text === '') return failure('unsupported-node-shape', 'a text node holds text: this one has none', path)
+    if (!isBareText(node) || nodeMarks(node).length !== depth + 1 || typeof text !== 'string' || text === '' || /[\n\r]/.test(text) || holdsNullCharacter(text)) return { carry: range }
-    if (/[\n\r]/.test(text)) return success({ carry: range })
-    if (holdsNullCharacter(text)) return failure('unspellable-character', 'a code span holds a null character CommonMark replaces', path)
     const fence = '`'.repeat(longestBacktickRun(text) + 1)
     spans.push(`${fence}${needsPadding(text) ? ` ${text} ` : text}${fence}`)
   }
-  return success({ segments: [syntax(spans.join(textBreakSpelling))] })
+  return { segments: [syntax(spans.join(textBreakSpelling))] }
 }
 
 function needsPadding(text: string): boolean {

src/markdown/parse/directive-nodes.ts

@@ -13,7 +13,7 @@ import { inlineMarkSpellingFault } from './directive-marks.ts'
 import { inlineNodeModel } from '../../adf/inline-nodes.ts'
 import { readEmptyKeys, spellsEmpty } from '../empty-keys.ts'
 import { readVocabulary } from './directive-attributes.ts'
-import { slotLineEndingFault } from '../directive-syntax.ts'
+import { slotFault } from '../directive-syntax.ts'
 import { textBreakName } from '../adjacent-text.ts'
 import { textDirectiveName } from '../text-directive.ts'
 
@@ -68,8 +68,8 @@ export function readInlineDirectiveNode(
     if (text === undefined) {
       return failure('unsupported-node-shape', `the ${name} content slot holds one text node carrying neither marks, attributes nor content: this one holds something else`, path)
     }
-    const spans = slotLineEndingFault(name, text)
+    const fault = slotFault(name, text)
-    if (spans !== undefined) return faulted(spans, path)
+    if (fault !== undefined) return faulted(fault, path)
     attrs.value[slot] = text
   }
   return success(namedNode(name, attrs.value, undefined, empty.value.empty))

src/markdown/parse/markdown-to-adf.test.ts

@@ -304,10 +304,8 @@ test('names the directive form a node CommonMark spells refuses', () => {
   assert.deepEqual(content(markdownToAdf('!adf:bulletList\n!adf:listItem\n---\n!adf:/listItem\n!adf:/bulletList\n')), [bulletList(item({ type: 'rule' }))])
 })
 
-// The spelling the emitter refuses gives the emitter's own error, never a second name for it.
+test('refuses the directive form of a blockquote opening with a code span', () => {
-test('gives back the refusal the CommonMark spelling itself raises', () => {
+  assert.equal(content(markdownToAdf('!adf:blockquote\n` `` `\n!adf:/blockquote\n')), 'unsupported-node-shape: blockquote takes the CommonMark spelling, not the directive form')
-  const lineStart = '!adf:blockquote\n` `` `\n!adf:/blockquote\n'
-  assert.equal(content(markdownToAdf(lineStart)), 'unspellable-line-start: block parsing would claim the emitted line "``` `` ```"')
 })
 
 test('names the directive name no node reads back to', () => {
@@ -1007,9 +1005,15 @@ test('names the content slot no lone plain text node reads back from', () => {
   assert.equal(content(markdownToAdf('!adf:status[!adf:text{text="\\n"}]{color=yellow}\n')), spans)
   assert.equal(content(markdownToAdf('!adf:status[a
b]{color=yellow}\n')), spans)
   assert.equal(content(markdownToAdf('!adf:status[a
b]{color=yellow}\n')), spans)
+  assert.equal(content(markdownToAdf('!adf:status[!adf:text{text="\\u0000"}]{color=yellow}\n')), 'unsupported-node-shape: the status content slot holds a null character: write the node as !adf:carry')
   assert.equal(content(markdownToAdf('Part !adf:mention{id=b1c2 text=A}.\n')), 'unsupported-node-shape: mention spells its text attribute in the content slot, never in {attrs}')
 })
 
+test('reads the characters CommonMark rewrites from their spellings', () => {
+  assert.deepEqual(content(markdownToAdf('a
b!adf:text{text="\\u0000\\u0000"}\n')), [paragraph('a\rb\u0000\u0000')])
+  assert.equal(content(markdownToAdf('!adf:text{text="\\u0000a"}\n')), 'unsupported-node-shape: text spells one run of spaces and tabs, one run of newlines, or one run of null characters: this one spells none of them')
+})
+
 test('reads the whitespace the reserved text directive carries', () => {
   assert.deepEqual(content(markdownToAdf('!adf:text{text="  "}a\n')), [paragraph('  a')])
   assert.deepEqual(content(markdownToAdf('a!adf:text{text="\\n"}b\n')), [paragraph('a\nb')])
@@ -1018,7 +1022,7 @@ test('reads the whitespace the reserved text directive carries', () => {
 })
 
 test('names the text directive spelling no whitespace run reads back from', () => {
-  const named = 'unsupported-node-shape: text spells one run of spaces and tabs, or one run of newlines: this one spells neither'
+  const named = 'unsupported-node-shape: text spells one run of spaces and tabs, one run of newlines, or one run of null characters: this one spells none of them'
   assert.equal(content(markdownToAdf('!adf:text{text=hi}\n')), named)
   assert.equal(content(markdownToAdf('!adf:text{text=" \\n"}\n')), named)
   assert.equal(content(markdownToAdf('!adf:text{text=""}\n')), named)

src/markdown/plain/adf-to-plain-markdown.test.ts

@@ -313,12 +313,13 @@ test('breaks a line at a newline and trims whitespace at every edge CommonMark s
   assert.equal(plain(paragraph(text(' x ', code))), '`  x  `\n')
   assert.equal(plain(node('heading', { level: 1 }, text(' h\ni '))), '# h i\n')
   assert.equal(plain(paragraph(text('a\r\u0000b'))), 'ab\n')
+  assert.equal(plain(paragraph(text('x', link('/u', 't\r\u0000')))), '[x](/u "t")\n')
+  assert.equal(plain(paragraph({ content: [text('dropped')], text: 'a', type: 'text' }, text('b'))), 'ab\n')
 })
 
-test('drops the code mark of a span opening a line with backticks that read as a fence', () => {
+test('keeps a code span opening a line, whose backticks open no fence', () => {
-  assert.equal(plain(paragraph(text('``` x', code))), '\\`\\`\\` x\n')
+  assert.equal(plain(paragraph(text('``` x', code))), '```` ``` x ````\n')
-  assert.equal(plain(paragraph(text('a\n'), text('``` x', code))), 'a\\\n\\`\\`\\` x\n')
+  assert.equal(plain(paragraph(text('a\n'), text('``` x', code))), 'a\\\n```` ``` x ````\n')
-  assert.equal(plain(paragraph(text('a '), text('``` x', code))), 'a ```` ``` x ````\n')
 })
 
 test('drops an empty paragraph and merges adjacent lists of one type', () => {

src/markdown/plain/editor-normal.test.ts

@@ -77,9 +77,9 @@ test('normalizes blocks and mark attributes nesting far past the levels a recurs
   assert.deepEqual(merged.content?.[0]?.content?.map((text) => text.text), ['ab'])
 })
 
-test('joins a text node holding content to no neighbour, so its content is kept', () => {
+test('drops the content a text node holds, and joins the node as any other', () => {
-  const holding: AdfNode = { content: [{ text: 'kept', type: 'text' }], text: 'a', type: 'text' }
+  const holding: AdfNode = { content: [{ text: 'dropped', type: 'text' }], text: 'a', type: 'text' }
-  for (const content of [[holding, { text: 'b', type: 'text' }], [{ text: 'b', type: 'text' }, holding]]) {
+  const normal = (content: AdfNode[]): AdfNode[] | undefined => toEditorNormal({ content: [{ content, type: 'paragraph' }], type: 'doc', version: 1 }).content
-    assert.deepEqual(toEditorNormal({ content: [{ content, type: 'paragraph' }], type: 'doc', version: 1 }).content, [{ content, type: 'paragraph' }])
+  assert.deepEqual(normal([holding, { text: 'b', type: 'text' }]), [{ content: [{ text: 'ab', type: 'text' }], type: 'paragraph' }])
-  }
+  assert.deepEqual(normal([{ text: 'b', type: 'text' }, holding]), [{ content: [{ text: 'ba', type: 'text' }], type: 'paragraph' }])
 })

src/markdown/plain/editor-normal.ts

@@ -7,9 +7,9 @@ type JsonContainer = JsonValue[] | { [key: string]: JsonValue }
 
 type NodeHolder = { content?: AdfNode[] }
 
-// The editor's rule is the reader's over the pair's editor-normal forms; a text node holding content never joins, so its content is kept.
+// The editor joins two text nodes where the reader would join their editor-normal forms.
 export function joinsWhenEditorNormal(previous: AdfNode, node: AdfNode): boolean {
-  if (previous.type !== 'text' || node.type !== 'text' || nodeContent(previous).length > 0 || nodeContent(node).length > 0) return false
+  if (previous.type !== 'text' || node.type !== 'text') return false
   return joinsWhenRead(normalNode(previous), normalNode(node))
 }
 
@@ -25,7 +25,8 @@ export function toEditorNormal(document: AdfDocument): AdfDocument {
     if (content.length === 0) continue
     entry.holder.content = content.map((source) => {
       const holder = normalNode(source)
-      pending.push({ holder, source })
+      // Atlassian's schema forbids content on a text node, so the editor drops it.
+      if (source.type !== 'text') pending.push({ holder, source })
       return holder
     })
   }

src/markdown/plain/inline-reduction.ts

@@ -149,7 +149,7 @@ function plainMarks(marks: readonly AdfMark[], container: LineContainer, text: s
 function plainLink(mark: AdfMark, container: LineContainer): AdfMark | undefined {
   const attrs = nodeAttrs(mark)
   const held = attrs['href']
-  const title = typeof attrs['title'] === 'string' ? attrs['title'].replace(/\r/g, '').replace(/\n/g, ' ') : undefined
+  const title = typeof attrs['title'] === 'string' ? attrs['title'].replace(/[\r\0]/g, '').replace(/\n/g, ' ') : undefined
   if (typeof held !== 'string') return undefined
   const href = writableHref(container === 'table-cell' ? held.replaceAll('|', '%7C') : held)
   if (title === undefined || spellLinkTarget(href, title) === undefined || (container === 'table-cell' && title.includes('|'))) return { attrs: { href }, type: 'link' }
@@ -267,21 +267,13 @@ function spellableLine(leaves: AdfNode[], container: LineContainer, path: Conver
 
 function withoutFallback(leaves: readonly AdfNode[], fallback: PlainLineFallback): AdfNode[] | undefined {
   if (fallback.kind === 'unspellable-run') return withoutMarks(leaves, fallback.runs)
-  const first = fallback.kind === 'opening-link' ? 0 : lineStart(leaves, fallback.line)
+  const mark = nodeMarks(leaves[0] ?? {})[0]
-  const mark = nodeMarks(leaves[first] ?? {})[0]
+  if (mark === undefined || mark.type !== 'link') return undefined
-  if (mark === undefined || mark.type !== (fallback.kind === 'opening-link' ? 'link' : 'code')) return undefined
+  let last = 0
-  let last = first
   while (sameMarkAt(nodeMarks(leaves[last + 1] ?? {}), [mark], 0)) last += 1
   // A code span is what binds the `]` a link definition reads, and dropping it keeps the link target.
-  const spans = leaves.slice(first, last + 1).some((leaf) => nodeMarks(leaf).length > 1 && nodeMarks(leaf).at(-1)?.type === 'code')
+  const spans = leaves.slice(0, last + 1).some((leaf) => nodeMarks(leaf).length > 1 && nodeMarks(leaf).at(-1)?.type === 'code')
-  if (mark.type === 'link' && spans) return leaves.map((leaf, index) => (index < first || index > last ? leaf : withMarks(leaf, nodeMarks(leaf).filter((held) => held.type !== 'code'))))
+  return spans ? leaves.map((leaf, index) => (index > last ? leaf : withMarks(leaf, nodeMarks(leaf).filter((held) => held.type !== 'code')))) : undefined
-  return withoutMarks(leaves, [{ depth: 0, first, last }])
-}
-
-function lineStart(leaves: readonly AdfNode[], line: number): number {
-  let index = 0
-  for (let breaks = 0; breaks < line && index < leaves.length; index += 1) if (leaves[index]?.type === 'hardBreak') breaks += 1
-  return index
 }
 
 // The runs cover disjoint leaves, so one pass drops them all.

src/markdown/text-directive.ts

@@ -2,7 +2,7 @@ import type { DirectiveSpan, Read } from './directive-syntax.ts'
 import { readSoleStringAttribute, spellAttributes, spellInlineLeafDirective, spellStringAttribute, unsupportedNodeShape } from './directive-syntax.ts'
 
 const name = 'text'
-const whitespaceRun = /^(?:[ \t]+|\n+)$/
+const spelledRun = /^(?:[ \t]+|\n+|\0+)$/
 
 export const textDirectiveName = name
 
@@ -14,6 +14,6 @@ export function readTextDirective(span: DirectiveSpan): Read<string> | undefined
   if (span.name !== name) return undefined
   const spelled = readSoleStringAttribute(span, name)
   if (spelled.fault !== undefined) return spelled
-  if (!whitespaceRun.test(spelled.value)) return { fault: unsupportedNodeShape(`${name} spells one run of spaces and tabs, or one run of newlines: this one spells neither`) }
+  if (!spelledRun.test(spelled.value)) return { fault: unsupportedNodeShape(`${name} spells one run of spaces and tabs, one run of newlines, or one run of null characters: this one spells none of them`) }
   return spelled
 }

src/result.ts

@@ -5,8 +5,6 @@ export type ConvertErrorCode =
   | 'unknown-directive-name'
   | 'unmappable-html'
   | 'unmappable-image'
-  | 'unspellable-character'
-  | 'unspellable-line-start'
   | 'unspellable-whitespace'
   | 'unsupported-document-version'
   | 'unsupported-nesting-depth'

todo.md

@@ -6,7 +6,7 @@
 
 `Bar = 9`
 
-`Next ID = 66`
+`Next ID = 74`
 
 | Goal | W |
 |---|---|
@@ -24,61 +24,56 @@
 
 | ID | Release | Exempt | Item | R | S | A | G | Goals | Score |
 |---|---|---|---|---|---|---|---|---|---|
-| 7 | 0.2.0 |  | **Ship HTML: `adfToHtml`, `htmlToAdf`, and `markdownToHtml` / `htmlToMarkdown` composed through ADF.** | 6 | 9 | 9 | 9 | 2, 3 | 25.8 |
+| 47 | 0.2.0 |  | **Open the README with what the package is, what it does and for whom.** | 1 | 4 | 7 | 9 | 3 | 26.0 |
-| 55 | 0.2.0 | defect | **Spell every document the emitter refuses today for a carriage return, a NUL, a code-span line start, a newline inside an emoji, mention or status, or a text node whose text is empty or missing, or which holds content.** | 5 | 5 | 7 | 9 | 1 | 25.8 |
+| 7 | 0.2.0 |  | **Ship HTML: `adfToHtml`, `htmlToAdf`, and `markdownToHtml` / `htmlToMarkdown` composed through ADF.** | 6 | 9 | 9 | 9 | 2, 4 | 25.8 |
 | 45 | 0.2.0 |  | **Replace `isAdfDocument` with a reader returning `Result<AdfDocument>`.** | 2 | 3 | 6 | 8 | 1 | 25.2 |
-| 6 | 0.2.0 | decision | **Specify the HTML dialect.** | 2 | 6 | 7 | 8 | 2, 3 | 24.7 |
+| 67 | 0.2.0 | defect | **Push an expand title's leaves one at a time, so a title carrying many text nodes returns a result.** | 1 | 1 | 4 | 9 | 1 | 24.8 |
-| 64 | 0.2.0 | defect | **Read back unchanged on V8 every JSON key the emitter writes, with a fixture whose key holds `\`, `"` or a control character.** | 4 | 4 | 6 | 8 | 1, 7 | 23.0 |
+| 6 | 0.2.0 | decision | **Specify the HTML dialect.** | 2 | 6 | 7 | 8 | 2, 4 | 24.7 |
-| 43 | 0.2.0 | decision | **Give each markdown input its own reader, strict to its own standard.** | 6 | 7 | 8 | 9 | 3, 4 | 22.3 |
+| 64 | 0.2.0 | defect | **Read back unchanged on V8 every JSON key the emitter writes, with a fixture whose key holds `\`, `"` or a control character.** | 4 | 4 | 6 | 8 | 1, 8 | 23.0 |
-| 65 | 0.2.0 | defect | **Read an image not alone in its paragraph as its alt text linked to its URL, and a titled image alone in its paragraph as the image captioned with its title.** | 5 | 5 | 7 | 7 | 3, 4, 6 | 18.7 |
+| 66 | 0.2.0 | defect | **Refuse an attribute value that is not a plain object, array or JSON primitive.** | 3 | 2 | 5 | 8 | 1 | 22.5 |
-| 49 | 0.2.0 |  | **Read a list whose bullet or ordered delimiter changes as two lists, in both readers, and retire `!adf:listBreak`.** | 4 | 5 | 5 | 8 | 3, 4 | 17.2 |
+| 71 | 0.2.0 |  | **Add a README table comparing the package with the other ADF converters, each cell checked against that package's own docs or behaviour.** | 1 | 3 | 6 | 7 | 3 | 21.2 |
+| 43 | 0.2.0 | decision | **Give each markdown input its own reader, strict to its own standard.** | 6 | 7 | 8 | 9 | 4, 5 | 20.3 |
+| 68 | 0.2.0 |  | **Carry a non-text inline node holding `content` or `text`, a block holding `text`, and a leaf block holding `content`.** | 3 | 3 | 4 | 7 | 1 | 18.2 |
+| 65 | 0.2.0 | defect | **Read an image not alone in its paragraph as its alt text linked to its URL, and a titled image alone in its paragraph as the image captioned with its title.** | 5 | 5 | 7 | 7 | 4, 5, 7 | 17.1 |
+| 70 | 0.2.0 |  | **Give `package.json` the `keywords` someone searching npm for an ADF converter types.** | 1 | 1 | 4 | 6 | 3 | 16.1 |
+| 72 | 0.2.0 |  | **Make GitHub the canonical repository, with `gitea.larvit.se/larvit/adf-codec` a read-only pull mirror of it.** | 5 | 6 | 5 | 8 | 3 | 16.0 |
+| 49 | 0.2.0 |  | **Read a list whose bullet or ordered delimiter changes as two lists, in both readers, and retire `!adf:listBreak`.** | 4 | 5 | 5 | 8 | 4, 5 | 15.5 |
+| 46 | 0.2.0 |  | **Publish the bundle size in the README, failing the release pipeline when it drifts.** | 2 | 4 | 5 | 5 | 3, 8 | 14.8 |
 | 61 | 0.2.0 | decision | **Have the emitter ask the inline reader how a line reads back, in place of `line-escaping.ts` predicting it.** | 6 | 8 | 3 | 8 | 1 | 14.0 |
-| 52 | 0.2.0 |  | **Spell `colwidth` as a comma list, `colwidth="340,420"`.** | 3 | 3 | 5 | 6 | 5 | 13.0 |
+| 52 | 0.2.0 |  | **Spell `colwidth` as a comma list, `colwidth="340,420"`.** | 3 | 3 | 5 | 6 | 6 | 11.5 |
-| 51 | 0.2.0 |  | **Match a reference label to its definition under Unicode case folding.** | 2 | 2 | 2 | 7 | 3, 4 | 12.4 |
+| 51 | 0.2.0 |  | **Match a reference label to its definition under Unicode case folding.** | 2 | 2 | 2 | 7 | 4, 5 | 10.9 |
-| 53 | 0.2.0 |  | **Put a block's `marks` spelling to the writer panel and adopt its pick.** | 4 | 5 | 5 | 6 | 5 | 11.5 |
 | 60 | 0.2.0 | decision | **Collect the questions `parse/` asks `emit/` into one named module.** | 3 | 4 | 2 | 6 | 2 | 10.7 |
 | 59 | 0.2.0 | decision | **Group the directive grammar into `src/markdown/directive/`, move `Read<T>` to `result.ts`, and move `Flavour` to `markdown/flavour.ts`.** | 3 | 5 | 2 | 6 | 2 | 10.4 |
-| 50 | 0.2.0 |  | **Read `[](/url)` and `[]()` as CommonMark's empty link.** | 4 | 4 | 3 | 6 | 3, 4, 6 | 10.4 |
+| 53 | 0.2.0 |  | **Put a block's `marks` spelling to the writer panel and adopt its pick.** | 4 | 5 | 5 | 6 | 6 | 10.0 |
 | 62 | 0.2.0 | decision | **Move the plain flavour's reading out of `parse/` and its writing out of `emit/` into `markdown/plain/`, so `emit/` no longer imports `plain/`.** | 4 | 5 | 2 | 6 | 2 | 9.4 |
+| 50 | 0.2.0 |  | **Read `[](/url)` and `[]()` as CommonMark's empty link.** | 4 | 4 | 3 | 6 | 4, 5, 7 | 9.0 |
+| 73 | 0.3.0 |  | **Announce the package where someone needing an ADF converter already reads: JRACLOUD-77436, the Atlassian developer community and Stack Overflow's ADF-to-markdown questions.** | 1 | 2 | 6 | 8 | 3 | 23.0 |
+| 9 | 0.3.0 |  | **Ship an online sandbox: a web page with two textboxes converting between ADF and markdown on the library's browser build.** | 2 | 6 | 6 | 8 | 3 | 21.0 |
 | 38 | 0.3.0 |  | **Spell a lone surrogate in a text node so it survives a UTF-8 encode.** | 2 | 2 | 4 | 7 | 1 | 19.5 |
-| 47 | 0.3.0 |  | **Open the README with what the package is, what it does and for whom.** | 1 | 4 | 7 | 9 | 9 | 14.0 |
+| 34 | 0.3.0 |  | **Read emphasis flanking by the whole character beside an astral symbol.** | 2 | 3 | 3 | 6 | 4, 5 | 11.3 |
-| 34 | 0.3.0 |  | **Read emphasis flanking by the whole character beside an astral symbol.** | 2 | 3 | 3 | 6 | 3, 4 | 12.6 |
-| 42 | 0.3.0 |  | **Trim a text leaf's trailing blanks in linear time.** | 1 | 2 | 5 | 9 | 8 | 12.5 |
-| 48 | 0.3.0 |  | **Keep the release path publishing past npm's bypass-2FA token retirement.** | 4 | 4 | 8 | 3 | 9 | 11.7 |
 | 31 | 0.3.0 |  | **Make the branch-coverage figure repeat across runs of an unchanged tree.** | 2 | 3 | 3 | 4 | 1 | 11.2 |
-| 33 | 0.3.0 |  | **Emit a line in time linear in its mark runs, in `adfToMarkdown` and `adfToPlainMarkdown`.** | 4 | 5 | 6 | 9 | 8 | 10.7 |
+| 42 | 0.3.0 | defect | **Trim a text leaf's trailing blanks in linear time.** | 1 | 2 | 5 | 9 | 9 | 10.5 |
-| 46 | 0.3.0 |  | **Publish the bundle size in the README, failing the release pipeline when it drifts.** | 2 | 4 | 5 | 5 | 7, 9 | 10.3 |
+| 33 | 0.3.0 | defect | **Emit a line in time linear in its mark runs, in `adfToMarkdown` and `adfToPlainMarkdown`.** | 4 | 5 | 6 | 9 | 9 | 8.7 |
-| 9 | 0.3.0 |  | **Ship an online sandbox: a web page with two textboxes converting between ADF and markdown on the library's browser build.** | 2 | 6 | 6 | 8 | 9 | 10.3 |
 | 56 | 0.3.0 | principle | **Give each piece of `blocks.ts`'s block-walk state and `inline-content.ts`'s `Scan` one owner that returns what it changes.** | 4 | 5 | 2 | 4 | 1 | 6.8 |
-| 57 | 0.3.0 | principle | **Make each `ci.sh` leg build what it reads, so one leg run alone tests the current tree.** | 2 | 3 | 1 | 3 | 7 | 1.2 |
+| 57 | 0.3.0 | principle | **Make each `ci.sh` leg build what it reads, so one leg run alone tests the current tree.** | 2 | 3 | 1 | 3 | 8 | 0.6 |
-| 58 | 0.3.0 | principle | **Port `ci.sh`, `publish.sh` and `docker-runner.sh` to standalone Python scripts.** | 4 | 6 | 1 | 2 | 7 | -2.2 |
+| 58 | 0.3.0 | principle | **Port `ci.sh`, `publish.sh` and `docker-runner.sh` to standalone Python scripts.** | 4 | 6 | 1 | 2 | 8 | -2.6 |
-| 8 | 0.4.0 |  | **Ship a CLI.** | 3 | 7 | 7 | 6 | 9 | 10.6 |
+| 8 | 0.4.0 |  | **Ship a CLI.** | 3 | 7 | 7 | 6 | 3 | 18.6 |
 
 ## Details
 
+### 47. Open the README with what the package is, what it does and for whom.
+
+Lands after item 72: the badges are npm's version and the GitHub Actions status. Today the README
+opens with the pre-launch rationale — Atlassian's REST APIs, `pf-editor-service/convert` being
+decommissioned, a link to JRACLOUD-77436. The background goes entirely, no endpoint, ticket or "why"
+note left. The README names the lossy pair, `adfToPlainMarkdown` and `plainMarkdownToAdf`, and the
+flavours it writes and reads — GitHub Flavored Markdown's alerts and task lists, Obsidian Flavored
+Markdown's callouts — so a search for any of these names finds the package.
+
 ### 7. Ship HTML: `adfToHtml`, `htmlToAdf`, and `markdownToHtml` / `htmlToMarkdown` composed through ADF.
 
 Lands after items 6, 59, 60, 61 and 62. The CommonMark spec suite also runs against
-`markdownToHtml`. The README documents HTML as it documents markdown, and its tagline and
+`markdownToHtml`. The README documents HTML as it documents markdown.
-`package.json`'s `description` regain HTML.
-
-### 55. Spell every document the emitter refuses today for a carriage return, a NUL, a code-span line start, a newline inside an emoji, mention or status, or a text node whose text is empty or missing, or which holds content.
-
-Today `inline-line.ts` refuses a carriage return or NUL in text, and a NUL in an emoji, mention or
-status (`unspellable-character`); and a paragraph opening with a code-span run
-(`unspellable-line-start`); `fencedTexts` refuses the same characters in a code block;
-`inline-line.ts` refuses a newline in an emoji, mention or status (`unspellable-whitespace`);
-`inline-line.ts` and `fencedTexts` refuse a text node whose `text` is empty or missing, and
-`inline-line.ts` one holding `content`. In text, a carriage return is CommonMark's `&#13;` (Goal 4),
-and a NUL is `!adf:text{text="\u0000"}` holding just the NUL, since CommonMark reads `&#0;` as
-U+FFFD (a writer panel, 3 of 3, 2026-10-04). The carries spell every other case: the inline carry in
-a paragraph, the block carry in a code block.
-
-The maintainer approved on 2026-10-04: §Markdown in is a canonical fixpoint drops its code-span
-exception, §Which code a cause takes drops `unspellable-whitespace` as an emitter cause;
-`unspellable-character` and `unspellable-line-start` retire. `unspellable-whitespace` stays, since
-the reader raises it for a content slot spanning a newline. Found by the README-goals audit,
-2026-10-03.
 
 ### 45. Replace `isAdfDocument` with a reader returning `Result<AdfDocument>`.
 
@@ -86,6 +81,13 @@ Goal 1 has every call return a result; the boolean guard is the one export that
 cannot say which branch refused, where `not-an-adf-document`'s message already does. Breaking:
 `MIGRATION.md` shows the guard's replacement.
 
+### 67. Push an expand title's leaves one at a time, so a title carrying many text nodes returns a result.
+
+`quoteNode`'s title loop (`parse/markdown-to-adf.ts`) spreads `inlineLeaves`'s result into
+`push`, against `docs/decisions.md` §Nothing spreads an unbounded array: an inline carry in a
+folded callout's title holding an unknown node with ~125k text children throws a `RangeError` from
+`plainMarkdownToAdf`. Found by the README-goals audit, 2026-10-04.
+
 ### 6. Specify the HTML dialect.
 
 Element-by-element mapping, the `data-*` fidelity scheme, the opaque-carry form, and the documented
@@ -101,6 +103,22 @@ Deno and Chrome the round-trip would refuse its own output or read back a differ
 tells which. Confirm with a fixture first; then read JSON with our own parser or record the gap with
 an ending item. Found by the README-goals audit, 2026-10-03.
 
+### 66. Refuse an attribute value that is not a plain object, array or JSON primitive.
+
+`isJsonValue` (`json-value.ts`) walks any object by `Object.values`, so a `Date`, `Map`, `Set` or
+typed array in `attrs`, as `structuredClone` keeps it, passes the guard and is written as `{}` or a
+key per element: `ok: true` with content lost. Accept an object whose prototype is
+`Object.prototype` or `null`, and an array. Found by the stability review of item 63, 2026-10-04.
+
+### 71. Add a README table comparing the package with the other ADF converters, each cell checked against that package's own docs or behaviour.
+
+Lands after items 7, 46 and 47: the table names HTML, compares item 46's size figure, and sits in
+the README item 47 reshapes. Its columns: which directions each converts, whether the round-trip
+holds, what an unknown node does, the formats, runtime dependencies and size. Candidates are the
+packages an npm search for ADF and markdown returns, marklassian among them. Every cell cites that
+package's README or a run against its published version, and the table names each version and the
+date it was checked. Found while planning discoverability, 2026-10-04.
+
 ### 43. Give each markdown input its own reader, strict to its own standard.
 
 Today `markdownToAdf` reads CommonMark and the lossless flavour as one input: text shaped like a
@@ -109,6 +127,14 @@ a code fence whose info string opens `adf:` becomes the block carry where Common
 caller names the markdown it hands in: CommonMark, read as its spec says, or the lossless flavour,
 read as `spec/flavour.md` says. Breaking: `MIGRATION.md` says which call a caller takes.
 
+### 68. Carry a non-text inline node holding `content` or `text`, a block holding `text`, and a leaf block holding `content`.
+
+`refuseContentAndText` (`emit/inline-line.ts`) and `emitDirectiveBlock` (`emit/adf-to-markdown.ts`)
+refuse these with `unsupported-node-shape`, though `isAdfDocument` accepts them and the carry
+round-trips them; `docs/decisions.md` §The code list gives a cause the carry answers no code. Drop
+them from the emitting half of the README's `unsupported-node-shape` row. Found by the README-goals
+audit, 2026-10-04.
+
 ### 65. Read an image not alone in its paragraph as its alt text linked to its URL, and a titled image alone in its paragraph as the image captioned with its title.
 
 Both are refused today with `unmappable-image`: 14 examples in
@@ -116,16 +142,39 @@ Both are refused today with `unmappable-image`: 14 examples in
 takes only Atlassian media ids, never a URL. An image not alone in its paragraph reads as its alt
 text, linked to its URL. Its title becomes the link's `title`. An empty alt text reads as the URL,
 as item 50 reads an empty link. A titled image alone in its paragraph reads as the image, with its
-title as a `caption` (the maintainer, 2026-10-04). By Goal 4, the lossless flavour reads both as
+title as a `caption` (the maintainer, 2026-10-04). By Goal 5, the lossless flavour reads both as
 CommonMark does. An image inside a link: `[![moon](moon.jpg)](/uri)` (spec example 517). Alone in
 its paragraph, it reads as the image with a `link` mark to `/uri`, which ADF's `media` takes. Not
 alone in its paragraph, the image reads as its alt text linked to `/uri`, and its URL drops. A
-writer panel chose this reading 3 of 3 (2026-10-04), by Goal 5, which outranks Goal 6.
+writer panel chose this reading 3 of 3 (2026-10-04), by Goal 6, which outranks Goal 7.
+
+### 70. Give `package.json` the `keywords` someone searching npm for an ADF converter types.
+
+`package.json` has none, and npm's search ranks on them. Take the terms the other ADF converters on
+npm list and the names the README uses — ADF, Atlassian Document Format, markdown, CommonMark, HTML
+— so a search for any of them can reach the package. Found while planning discoverability,
+2026-10-04.
+
+### 72. Make GitHub the canonical repository, with `gitea.larvit.se/larvit/adf-codec` a read-only pull mirror of it.
+
+The maintainer's call, 2026-10-04: GitHub is where an ADF converter is searched for, and the Gitea
+copy keeps the move back open. The workflows move to `.github/workflows/` with `ci.sh` unchanged.
+Publishing moves to npm's trusted publishing over OIDC, which GitHub-hosted Actions support, and
+which outlives the bypass-2FA token npm retires around January 2027: `publish.sh` drops `NPM_TOKEN`
+for the Actions OIDC variables, and AGENTS.md §7 reserves the trusted-publisher setup in place of
+the secret. `package.json`'s `repository` moves and it gains `bugs` and `homepage`. The links in
+README, CHANGELOG and MIGRATION follow, as do AGENTS.md's forge commands and merge style.
+`docs/decisions.md` gains the entry "GitHub is canonical, and Gitea a pull mirror of it" (Goal 3),
+and §Public on npm and §Publish on a version bump are revised: the source is public on GitHub, and
+CI publishes through npm's trusted publisher. Gitea's open issues and its releases move to GitHub
+first, since a mirror carries only git refs; the mirror disables issues and its description points
+at GitHub. Creating the GitHub repository, configuring npm's trusted publisher, and re-creating the
+Gitea copy as a mirror (Gitea cannot convert an existing repository) are the maintainer's.
 
 ### 49. Read a list whose bullet or ordered delimiter changes as two lists, in both readers, and retire `!adf:listBreak`.
 
 Lands after item 43. Today `- a` then `+ b`, or `1.` then `1)`, reads as one list; CommonMark reads
-two (spec examples 301 and 302). Goal 4 settles it for the lossless flavour too: CommonMark spells
+two (spec examples 301 and 302). Goal 5 settles it for the lossless flavour too: CommonMark spells
 adjacent lists by changing the marker, so `adfToMarkdown` and `adfToPlainMarkdown` alternate `-` and
 `*` between adjacent bullet lists and `.` and `)` between adjacent ordered lists, and
 `!adf:listBreak` retires. `*` is the maintainer's pick (2026-10-04). Breaking, so it ships beside
@@ -133,11 +182,23 @@ item 43: `MIGRATION.md`'s Readings and Spellings tables gain their rows. Example
 their `pending` exceptions, and the spelling leaves the README's "Four CommonMark spellings" bullet,
 which counts one fewer.
 
+### 46. Publish the bundle size in the README, failing the release pipeline when it drifts.
+
+Lands after item 7, which changes it. The quantity is what a consumer downloads and loads: the
+tarball `npm pack` produces, its unpacked `dist`, and the built JavaScript minified + gzipped — the
+figure the competitors advertise (marklassian's "12kb") and the only apples-to-apples one, since
+ours ships tsc's unminified output and no minifier yet (decide here whether to minify for the build
+or report the unminified gzip). The figure lands in README §The package beside the "no runtime
+dependencies" claim. Measured today, unminified: tarball 60.4 kB, unpacked 221.5 kB, JS gzipped 45.6
+kB.
+
 ### 61. Have the emitter ask the inline reader how a line reads back, in place of `line-escaping.ts` predicting it.
 
 The comprehension panel's worst place: `escapeClaims` and `escapeClosedRuns` re-implement the
 reader's view — flanking, code-span closers, link-definition openings, highlight flanking — and
-only the property tests catch drift. It caps the panel's Locality score.
+only the property tests catch drift. It caps the panel's Locality score. The replacement runs in
+time linear in the line: today `mergesWithSyntax`, `touchesSyntax` and `closesHeading` rescan a run
+of one character from each of its characters.
 
 ### 52. Spell `colwidth` as a comma list, `colwidth="340,420"`.
 
@@ -151,12 +212,6 @@ example 540); lowercasing and then uppercasing folds it. Breaking, so it ships b
 `MIGRATION.md`'s Readings table gains its row. Its `pending` exceptions go, and its spelling leaves
 the README's "Four CommonMark spellings" bullet, which counts one fewer.
 
-### 53. Put a block's `marks` spelling to the writer panel and adopt its pick.
-
-Today `marks="[{\"attrs\":{\"mode\":\"wide\"},\"type\":\"breakout\"}]"`, the marks array as
-escaped JSON. Breaking where the panel picks another spelling: `MIGRATION.md`'s Spellings table
-gains its row.
-
 ### 60. Collect the questions `parse/` asks `emit/` into one named module.
 
 `parse/` asks `emit/` through `commonMarkSpelling` and `openingLinkTakesDirective`, each imported
@@ -169,14 +224,11 @@ Eight directive files sit across three directories, and the `markdown/` root hol
 needs `Read<T>` and `Flavour` out of the plain flavour and `markdown/`; it needs the carry and the
 mark spellings too, which item 7 moves where it learns what HTML shares.
 
-### 50. Read `[](/url)` and `[]()` as CommonMark's empty link.
+### 53. Put a block's `marks` spelling to the writer panel and adopt its pick.
 
-Both stay literal text today (spec examples 484 and 487). ADF holds no empty text node to carry a
+Today `marks="[{\"attrs\":{\"mode\":\"wide\"},\"type\":\"breakout\"}]"`, the marks array as
-link mark, so a link whose text is empty takes its URL as its text (the maintainer, 2026-10-04):
+escaped JSON. Breaking where the panel picks another spelling: `MIGRATION.md`'s Spellings table
-`[](/url)` reads as `/url` linked to `/url`. `[]()` has no URL to show; the chunk settles it by Goals
+gains its row.
-3 and 6. Breaking, so it ships beside item 43: `MIGRATION.md`'s Readings table gains its row. Its
-`pending` exceptions go, and its spelling leaves the README's "Four CommonMark spellings" bullet,
-which counts one fewer.
 
 ### 62. Move the plain flavour's reading out of `parse/` and its writing out of `emit/` into `markdown/plain/`, so `emit/` no longer imports `plain/`.
 
@@ -186,46 +238,32 @@ the `inlineLeaves` use. Writing: `spellPlainBlock`, `quotedUnder`, `tryTaskList`
 `plain/conventions.ts`, which `emit/` imports them from; item 59 moves `Flavour`. Every
 comprehension reader on 2026-10-03 named the plain flavour's spread across three directories.
 
+### 50. Read `[](/url)` and `[]()` as CommonMark's empty link.
+
+Both stay literal text today (spec examples 484 and 487). ADF holds no empty text node to carry a
+link mark, so a link whose text is empty takes its URL as its text (the maintainer, 2026-10-04):
+`[](/url)` reads as `/url` linked to `/url`. `[]()` has no URL to show; the chunk settles it by Goals
+4 and 7. Breaking, so it ships beside item 43: `MIGRATION.md`'s Readings table gains its row. Its
+`pending` exceptions go, and its spelling leaves the README's "Four CommonMark spellings" bullet,
+which counts one fewer.
+
+### 73. Announce the package where someone needing an ADF converter already reads: JRACLOUD-77436, the Atlassian developer community and Stack Overflow's ADF-to-markdown questions.
+
+Lands after `0.2.0` is published with items 47, 71 and 72, so each post links the GitHub repository,
+the comparison and a README that opens with what the package is. We draft each post for the place it
+goes; the maintainer posts them. Found while planning discoverability, 2026-10-04.
+
 ### 38. Spell a lone surrogate in a text node so it survives a UTF-8 encode.
 
 `adfToMarkdown` emits it verbatim, so markdown stored as UTF-8 reads back U+FFFD; attribute values
 already escape it.
 
-### 47. Open the README with what the package is, what it does and for whom.
-
-It opens with the pre-launch rationale — Atlassian's REST APIs, `pf-editor-service/convert` being
-decommissioned, a link to JRACLOUD-77436. The background goes entirely, no endpoint, ticket or "why"
-note left. The badges are npm's version and the Gitea Actions status. The README names the lossy
-pair, `adfToPlainMarkdown` and `plainMarkdownToAdf`, and the flavours it writes and reads — GitHub
-Flavored Markdown's alerts and task lists, Obsidian Flavored Markdown's callouts — so a search for
-any of these names finds the package.
-
 ### 34. Read emphasis flanking by the whole character beside an astral symbol.
 
 Check whether `line-escaping.ts`'s `charAt` and the parser's flanking read one UTF-16 unit beside an
 astral symbol — a lone surrogate is neither punctuation nor symbol, where CommonMark reads `😀` as
 punctuation — and, where they do, read the code point, with a fixture per direction.
 
-### 42. Trim a text leaf's trailing blanks in linear time.
-
-`plain/inline-reduction.ts`'s `leafEdges` finds the trail with an unanchored `/[ \t]*$/`, quadratic
-in a run of blanks inside one leaf: a paragraph of `a`, 80 000 spaces, `b` takes 6.5 s in
-`adfToPlainMarkdown`. Scan backward, as the expand title's trim does.
-
-### 48. Keep the release path publishing past npm's bypass-2FA token retirement.
-
-Lands after 2027-01-01, or after a release run fails on the token, whichever comes first: the
-maintainer chose on 2026-10-02 to wait and see whether the retirement bites. It holds back no
-release: when the rest of its release is done, it moves to the next. `0.1.0` published only once the
-npm token carried **Bypass 2FA**: the account requiring no 2FA on writes was not enough, and npm
-answered `EOTP` until the token itself bypassed. npm retires bypass-2FA tokens for direct publishing
-around January 2027, leaving them `npm stage publish`, which a maintainer approves with 2FA; its
-replacement — trusted publishing over OIDC — supports GitHub-hosted Actions, GitLab.com's shared
-runners and CircleCI's cloud, self-hosted runners planned without a date. Revisit: whether npm has
-added Gitea or self-hosted OIDC, and otherwise whether the release moves to the staged publish —
-which fits badly with publish-on-merge, and is the maintainer's trade to weigh. The Goals and G
-cells are provisional: no README goal covers the release path.
-
 ### 31. Make the branch-coverage figure repeat across runs of an unchanged tree.
 
 Three Node test legs over one unchanged tree reported `emit/inline-line.ts` at 95.83%, 96.23% and
@@ -237,21 +275,19 @@ moves upward, so the first raise to the measured figure reddens a run that chang
 measurement repeatable, or state the number the floor may be raised to and why it is not the
 measured one.
 
+### 42. Trim a text leaf's trailing blanks in linear time.
+
+`plain/inline-reduction.ts`'s `leafEdges` finds the trail with an unanchored `/[ \t]*$/`, quadratic
+in a run of blanks inside one leaf: a paragraph of `a`, 80 000 spaces, `b` takes 6.5 s in
+`adfToPlainMarkdown`. Scan backward, as the expand title's trim does.
+
 ### 33. Emit a line in time linear in its mark runs, in `adfToMarkdown` and `adfToPlainMarkdown`.
 
 `adfToMarkdown` spends 23 s on one paragraph of 2000 × `un` plus `**-r**`: each run its flanking
 cannot spell re-emits the whole line before riding the carry, quadratic in the runs, and the plain
-reduction's `spellableLine` drops one mark per re-emit the same way. Make both linear.
+reduction's `spellableLine` drops one mark per re-emit the same way. An inline node whose
-
+attributes no spelling writes re-emits the line the same way before riding the carry. Make all
-### 46. Publish the bundle size in the README, failing the release pipeline when it drifts.
+three linear.
-
-Lands after item 7, which changes it. The quantity is what a consumer downloads and loads: the
-tarball `npm pack` produces, its unpacked `dist`, and the built JavaScript minified + gzipped — the
-figure the competitors advertise (marklassian's "12kb") and the only apples-to-apples one, since
-ours ships tsc's unminified output and no minifier yet (decide here whether to minify for the build
-or report the unminified gzip). The figure lands in README §The package beside the "no runtime
-dependencies" claim. Measured today, unminified: tarball 60.4 kB, unpacked 221.5 kB, JS gzipped 45.6
-kB.
 
 ### 56. Give each piece of `blocks.ts`'s block-walk state and `inline-content.ts`'s `Scan` one owner that returns what it changes.
 
@@ -259,7 +295,11 @@ Technical principle "One owner per value": the `Walk` record passes through twel
 mutate it and return `void`; `walk.leaf` alone is written in seven places. `ContainerStack` in the
 same file shows the shape to follow. `inline-content.ts`'s `Scan` has the same shape: about fifteen
 functions write `pending`, `pieces`, `deactivatedBefore` and `openingSpellableLink` and return
-`void`, and `parseInlineContent` reads a flag `scanInline` leaves on it.
+`void`, and `parseInlineContent` reads a flag `scanInline` leaves on it. The same shape recurs in
+`mintTaskIds` (`plain/task-ids.ts`), which writes `attrs` on the document `readDocument` built;
+`takeFallback` (`emit/inline-line.ts`), which writes the record the next `lineSegments` pass reads;
+`writeUnpaired`, `markPairings` and `markHighlights` (`inline-content.ts`), whose order changes the
+output; and `nestIn` (`plain/adf-to-plain-markdown.ts`), which pushes into its caller's array.
 
 ### 57. Make each `ci.sh` leg build what it reads, so one leg run alone tests the current tree.