Flavour spec 1a: the directive grammar, canonical form, opaque carry #3

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lilleman merged 7 commits from flavour-grammar into main 2026-08-24 00:49:26 +02:00
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## 3. Unknown input policy
- Unknown ADF node: carried opaquely — raw JSON rides a dedicated syntax in both formats, restored
byte-for-byte. The round-trip holds for documents newer than the library.
- Unknown ADF node: carried opaquely — raw JSON rides a dedicated syntax in both formats and
restores to a deep-equal node. The round-trip holds for documents newer than the library.
- Unmappable foreign HTML element: error result naming the element — never a silent drop.
- Bare `@name` / `:smile:` in typed text: stays a text node. Only directives produce
mention/emoji/media nodes; resolving names to ids needs I/O, which is the consumer's job.
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# The markdown flavour
The grammar of the extended markdown `adfToMarkdown` emits and `markdownToAdf` parses. Plain
CommonMark is a subset: the flavour adds directives, never changes CommonMark meaning. The emitted
form is contract (AGENTS.md §8). Per-node syntaxes build on this grammar in sections that follow
(todo.md 1b1c).
CommonMark is a subset with one carve-out: literal text that matches directive syntax below is
claimed by the flavour (escape the `:` to keep it literal). The emitted form is contract
(AGENTS.md §8). Per-node syntaxes build on this grammar in sections that follow (todo.md 1b1c).
## Canonical form
@@ -12,15 +12,19 @@ normalizes to it through the round-trip.
- Emphasis `_em_`, strong `**strong**`; `*` replaces `_` only where `_` cannot parse
(intra-word).
- Bullet lists `- `, two-space continuation indent. Ordered lists incrementing `1.` `2.` `3.`,
the first number taken from the node's `order` attribute.
- Bullet lists `- `; ordered lists incrementing `1.` `2.` `3.`, the first number taken from the
node's `order` attribute. Continuation lines align with the first character after the marker
(two spaces for `- `, three for `1. `). Lists are tight — blank lines between items normalize
away; ADF does not record tightness.
- Blockquotes prefix every line with `> `.
- ATX headings (`#``######`); setext input normalizes to ATX.
- Code fences ``` with the node's language as info string, the fence lengthened past any backtick
run in the content; indented-code input normalizes to fences.
- Thematic break `---`.
- Hard break: backslash at end of line (survives editors that trim trailing spaces).
- Links `[text](url)`; `<…>` around a destination containing spaces; title in double quotes;
`<url>` autolink when the link text equals its destination.
- Links `[text](url)`; `<…>` around a destination containing spaces; title in double quotes.
`<url>` autolink form only when the text equals the destination and the destination is a valid
CommonMark autolink (absolute URI).
- Paragraphs on one line — no soft wrapping; soft line breaks in input collapse per CommonMark.
- Entity references in input decode to their characters; output backslash-escapes only where text
would otherwise parse as syntax.
@@ -28,11 +32,19 @@ normalizes to it through the round-trip.
## Directives
One grammar for everything CommonMark lacks. Names are the ADF node names (camelCase).
One grammar for everything CommonMark lacks. A directive name is `[a-z][A-Za-z0-9]*` — the ADF
node names. Recognition is syntactic and name-set-independent: anything matching the forms below
parses as a directive regardless of whether the name is known, and an unknown name is an error
result naming it — so output an old emitter escaped stays escaped, and erroring input gaining
meaning later is MINOR, never a reparse (§8). The name `adf` is reserved for the opaque carry, as
both directive name and fence info string.
**Inline**: `:name[content]{attrs}`. `[content]` is inline markdown; each node's section says
whether content and attrs are required. `:` opens a directive only when the name is followed
immediately by `[` or `{` — anything else (`10:30`, `:smile:`) is literal text.
**Inline**: `:name[content]{attrs}`, on one line — an inline directive never spans lines.
`[content]` is inline markdown; brackets inside balance as in CommonMark link text, `\]` for a
literal bracket. Each node's section says whether content and attrs are required. `:` opens a
directive only when the name is followed immediately by `[` or `{`, and `{attrs}` must follow
`]` (or the name) with no gap — anything else (`10:30`, `:smile:`, a stray `{…}` in text) is
literal text.
**Container block**:
@@ -45,25 +57,35 @@ block content
The fence is three or more colons. `arg` is one optional bare token whose meaning each node
defines (e.g. the panel type). The body is block markdown. The closing fence is a line of at
least the opening's length, and a container's fence is longer than every directive fence line in
its body, so closers are unambiguous — the code-fence rule. Canonical form uses minimal lengths.
its body — counting only lines that parse as directive fences in the body's block structure; a
colon run inside a code fence or opaque carry is content. Canonical form uses minimal lengths.
**Leaf block**: `::name {attrs}` — a block-position node with no body.
**Attributes**: `{key=value key2="two words"}`. A bare value matches `[A-Za-z0-9_-]+`; anything
else is double-quoted with `\"` and `\\` as the only escapes. All values are strings at the
grammar level; each node's section assigns types. Canonical form orders keys alphabetically and
spells values bare wherever allowed.
**Attributes**: `{key=value key2="two words"}`. A bare value matches `[A-Za-z0-9_-]+`; any other
value is double-quoted with JSON string escaping (`\"` `\\` `\n` `\t` `\uXXXX`, …) — total over
Unicode, and raw newlines never appear inside quotes. All values are strings at the grammar
level; each node's section assigns types. Canonical form orders keys alphabetically and spells
values bare wherever allowed.
**Escaping**: the emitter backslash-escapes a `:` whose text would otherwise parse as a
directive; a backslash before `:` in input always yields a literal colon.
**Escaping**: the emitter backslash-escapes whatever literal text would otherwise parse as
directive syntax — the leading `:` of a would-be directive, `]` inside content; a backslash
before `:` in input always yields a literal colon.
**Malformed directives are error results**, named: an unclosed container at end of input, a body
fence line of the container's length or longer, unparseable or duplicate-keyed attrs, invalid
JSON in an opaque carry. Never a silent literal-text fallback — a typo that reparses as prose is
the silent loss §2 refuses.
## The opaque carry (AGENTS.md §3)
A node type the library does not know rides as its raw JSON and restores to a deep-equal node:
A node type the library does not know rides as its raw JSON and restores to a deep-equal node.
Block and inline positions canonicalize differently, each fitting where it sits:
- **Block position**: a fenced code block with info string `adf`, body = the node's JSON,
serialized canonically — two-space indent, object keys sorted.
- **Inline position**: `:adf{json="…"}`, same serialization, quote-escaped.
- **Block position**: a fenced code block with info string `adf`, body = the node's JSON
two-space indent, object keys sorted.
- **Inline position**: `:adf{json="…"}` — compact serialization (keys sorted, no whitespace),
JSON-string-escaped into the attribute.
The info string `adf` is reserved: a genuine `codeBlock` whose `language` is exactly `adf` is
itself emitted through the opaque carry, so the reservation stays absolute and stays lossless.
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- [ ] **1d — Corpus start** (§10): checked-in ADF ↔ canonical-markdown fixture pairs per spec'd
node.
- [ ] **2 — `adfToMarkdown`.** First real code — decide here where §10's coverage check lives.
- [ ] **3 — `markdownToAdf`.** The CommonMark parser is the largest single component.
- [ ] **3 — `markdownToAdf`.** The CommonMark parser is the largest single component. The raw-HTML
element mapping is empty until milestone 6, so at `0.1.0` every raw-HTML construct in input
is an error result.
- [ ] **4 — Round-trip property tests** over the corpus, both ways — the thing that proves 2 and 3.
- [ ] **5 — Release pipeline, ship `0.1.0`.** Publish-on-version-change (§9), `NPM_TOKEN` secret,
the repo made public first (§6). `0.1.0` is the markdown round-trip: both markdown