File item 54: the source-parting decision misses an import parse/ takes from emit/

MIGRATION.md

@@ -22,7 +22,8 @@ import { markdownToAdf as markdownToAdf010 } from 'adf-codec-0.1'
 
 function migrateMarkdown(stored: string) {
   const parsed = markdownToAdf010(stored)
-  return parsed.ok ? adfToMarkdown(parsed.value) : parsed
+  // 0.1.0's reader was editor-normal, so a document with no content key always meant an empty one.
+  return parsed.ok ? adfToMarkdown({ ...parsed.value, content: parsed.value.content ?? [] }) : parsed
 }
 ```
 

corpus/errors/carry-fence-type-unspellable.error

@@ -0,0 +1 @@
+unsupported-node-shape

corpus/errors/carry-fence-type-unspellable.md

@@ -0,0 +1,3 @@
+```adf:\\
+{}
+```

docs/decisions.md

@@ -38,10 +38,10 @@ shape the editor would not.
 
 "Equals" is `assert.deepStrictEqual`: every key and value `doc` holds, two adjacent text nodes, an
 empty `attrs`, `content` or `marks` and `-0` included, with no normalization on either side.
-CommonMark's spelling stays wherever a document holds none of those shapes. The plain flavour is
+CommonMark's spelling stays wherever a document holds none of those shapes. The plain reader
-lossy and stays editor-normal: its reduction reads and writes ADF with adjacent text nodes of
+builds what is written, as `markdownToAdf` does. Only the plain writer is lossy: its reduction
-identical marks and no attributes merged, `-0` read as `0`, and an empty `attrs`, `content` or
+writes editor-normal ADF — adjacent text nodes of identical marks and no attributes merged, `-0`
-`marks` the absent key.
+as `0`, and an empty `attrs`, `content` or `marks` the absent key.
 
 ## `!adf:textBreak{}` parts text CommonMark would join
 

src/adf/document.ts

@@ -68,8 +68,22 @@ export function identicalMark(left: AdfMark, right: AdfMark): boolean {
   return marksKey([left]) === marksKey([right])
 }
 
-export function identicalMarks(left: AdfNode, right: AdfNode): boolean {
+export function identicalMarks(left: readonly AdfMark[], right: readonly AdfMark[]): boolean {
-  return marksKey(nodeMarks(left)) === marksKey(nodeMarks(right))
+  return marksKey(left) === marksKey(right)
+}
+
+// `joins` is the caller's: a reader joins what CommonMark reads as one, editor-normal ADF what the editor would.
+export function mergeAdjacentText(nodes: readonly AdfNode[], joins: (previous: AdfNode, node: AdfNode) => boolean): AdfNode[] {
+  const merged: AdfNode[] = []
+  for (const node of nodes) {
+    const previous = merged[merged.length - 1]
+    if (previous !== undefined && joins(previous, node)) {
+      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
+      continue
+    }
+    merged.push(node)
+  }
+  return merged
 }
 
 // Depth is the walks' business, not the shape's: the guard waves a deep document through as blocks and marks do.

src/adf/editor-normal.ts

@@ -1,34 +1,25 @@
 import type { AdfAttributes, AdfDocument, AdfMark, AdfNode } from './document.ts'
 import type { JsonValue } from '../json-value.ts'
-import { nodeAttrs, nodeContent, nodeMarks } from './document.ts'
+import { identicalMark, identicalMarks, mergeAdjacentText, nodeAttrs, nodeContent, nodeMarks } from './document.ts'
-import { serializeCanonicalJson } from '../canonical-json.ts'
 
 type JsonContainer = JsonValue[] | { [key: string]: JsonValue }
 
 type NodeHolder = { content?: AdfNode[] }
 
-export function sameMark(candidate: AdfMark, mark: AdfMark): boolean {
+export function sameMark(left: AdfMark, right: AdfMark): boolean {
-  return markKey(candidate) === markKey(mark)
+  return identicalMark(normalMark(left), normalMark(right))
 }
 
-export function mergeAdjacentText(nodes: readonly AdfNode[]): AdfNode[] {
+export function joinsNormally(previous: AdfNode, node: AdfNode): boolean {
-  const merged: AdfNode[] = []
+  if (!mergesText(previous) || !mergesText(node)) return false
-  for (const node of nodes) {
+  return identicalMarks(nodeMarks(previous).map(normalMark), nodeMarks(node).map(normalMark))
-    const previous = merged[merged.length - 1]
-    if (previous !== undefined && mergesText(previous) && mergesText(node) && sameMarks(previous, node)) {
-      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
-      continue
-    }
-    merged.push(node)
-  }
-  return merged
 }
 
 export function toEditorNormal(document: AdfDocument): AdfDocument {
   const normal: AdfDocument = { type: document.type, version: Object.is(document.version, -0) ? 0 : document.version }
   const pending: { holder: NodeHolder; source: NodeHolder }[] = [{ holder: normal, source: document }]
   for (let entry = pending.pop(); entry !== undefined; entry = pending.pop()) {
-    const content = mergeAdjacentText(nodeContent(entry.source))
+    const content = mergeAdjacentText(nodeContent(entry.source), joinsNormally)
     if (content.length === 0) continue
     entry.holder.content = content.map((source) => {
       const holder = normalNode(source)
@@ -76,15 +67,3 @@ function normalValue(value: JsonValue, pending: JsonContainer[]): JsonValue {
 function mergesText(node: AdfNode): boolean {
   return node.type === 'text' && Object.keys(nodeAttrs(node)).length === 0
 }
-
-function sameMarks(previous: AdfNode, node: AdfNode): boolean {
-  return marksKey(nodeMarks(previous)) === marksKey(nodeMarks(node))
-}
-
-function marksKey(marks: readonly AdfMark[]): string {
-  return marks.map(markKey).join('\n')
-}
-
-function markKey(mark: AdfMark): string {
-  return `${mark.type} ${serializeCanonicalJson(normalAttributes(nodeAttrs(mark)) ?? {}, 'compact')}`
-}

src/conformance/property-harness.ts

@@ -10,8 +10,9 @@ import { blockArgument } from '../markdown/block-directive.ts'
 import { blockNodes } from '../adf/block-nodes.ts'
 import { directivePrefix } from '../markdown/directive-syntax.ts'
 import { inlineNodes } from '../adf/inline-nodes.ts'
+import { joinsNormally } from '../adf/editor-normal.ts'
 import { markAttributes } from '../adf/mark-attributes.ts'
-import { mergeAdjacentText } from '../adf/editor-normal.ts'
+import { mergeAdjacentText } from '../adf/document.ts'
 
 type Positions = { block: AdfNode; inline: AdfNode }
 
@@ -92,7 +93,7 @@ function withoutEmptyKeys<T extends AdfMark | AdfNode>(held: T): T {
 }
 
 function occasionallyApart(arbitrary: Arbitrary<AdfNode[]>): Arbitrary<AdfNode[]> {
-  return fc.tuple(arbitrary, fc.nat({ max: 5 })).map(([nodes, roll]) => (roll === 0 ? nodes : mergeAdjacentText(nodes)))
+  return fc.tuple(arbitrary, fc.nat({ max: 5 })).map(([nodes, roll]) => (roll === 0 ? nodes : mergeAdjacentText(nodes, joinsNormally)))
 }
 
 function pipeTable({ body, header }: { body: AdfNode[][]; header: AdfNode[] }): AdfNode {

src/markdown/emit/plain-inline.ts

@@ -3,9 +3,9 @@ import type { LineContainer } from '../line-container.ts'
 import type { MarkRun } from './line-escaping.ts'
 import { blockNodeModel } from '../../adf/block-nodes.ts'
 import { failure, success, type ConvertErrorPath, type Result } from '../../result.ts'
+import { joinsNormally, sameMark } from '../../adf/editor-normal.ts'
 import { largestNesting } from '../../nesting.ts'
-import { mergeAdjacentText, sameMark } from '../../adf/editor-normal.ts'
+import { mergeAdjacentText, nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
-import { nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
 import { plainLineFallback, type PlainLineFallback } from './inline-line.ts'
 import { spellDestination, spellLinkTarget } from '../commonmark/link-syntax.ts'
 
@@ -193,7 +193,7 @@ function withMarks(leaf: AdfNode, marks: readonly AdfMark[]): AdfNode {
 
 function trimmedEdges(leaves: readonly AdfNode[]): AdfNode[] {
   for (let current = leaves; ; ) {
-    const merged = withoutEdgeBreaks(mergeAdjacentText(current))
+    const merged = withoutEdgeBreaks(mergeAdjacentText(current, joinsNormally))
     let changed = false
     const trimmed: AdfNode[] = []
     for (const [index, leaf] of merged.entries()) {

src/markdown/emit/plain-reduction.test.ts

@@ -64,6 +64,7 @@ test('refuses what the document guard refuses, and nothing else', () => {
   let deep: AdfNode = said('x')
   for (let level = 0; level <= largestNesting; level += 1) deep = { content: [deep], type: 'layoutColumn' }
   assert.match(plainDocument(document(deep)), /^unsupported-nesting-depth at \/content\/0(\/content\/0)+$/)
+  assert.match(plainDocument(document(paragraph(text('a'), text('b')), text('c'), text('d'), deep)), /^unsupported-nesting-depth at \/content\/3(\/content\/0)+$/)
   let deepInline: AdfNode = text('x')
   for (let level = 0; level <= largestNesting; level += 1) deepInline = { content: [deepInline], type: 'unknownInline' }
   assert.match(plainDocument(document(paragraph(deepInline))), /^unsupported-nesting-depth at /)

src/markdown/emit/plain-reduction.ts

@@ -51,8 +51,8 @@ export function reduceToPlain(document: AdfDocument): Result<AdfDocument> {
   const fault = adfDocumentFault(document)
   if (fault !== undefined) return faulted(fault, [])
   if (document.version !== 1) return failure('unsupported-document-version', `no markdown spelling carries ADF version ${document.version}`, [])
-  // docs/decisions.md §Equality is deep: the plain flavour reads and writes editor-normal ADF.
+  // A refusal's path indexes the caller's document, so only the reduction's output normalizes (docs/decisions.md §Equality is deep).
-  const blocks = reduceBlocks(nodeContent(toEditorNormal(document)), { depth: 0, memo: new Map(), path: [] })
+  const blocks = reduceBlocks(nodeContent(document), { depth: 0, memo: new Map(), path: [] })
   return blocks.ok ? success({ content: nodeContent(toEditorNormal({ content: blocks.value, type: 'doc', version: 1 })).slice(), type: 'doc', version: 1 }) : blocks
 }
 

src/markdown/opaque-carry.ts

@@ -33,6 +33,9 @@ export function carriedInline(node: AdfNode, path: ConvertErrorPath): Result<str
 }
 
 export function readCarriedBlock(type: string, body: string, depth: number): Read<AdfNode> {
+  if (type !== '' && !infoStringCarries(type)) {
+    return { fault: unsupportedNodeShape(`the carry fence names a type no info string carries back: spell it ${carryFencePrefix} with the type in the JSON`) }
+  }
   const read = readCarriedJson(body, 'two-space', largestNesting - depth, type)
   if (read.fault !== undefined || type !== '' || !infoStringCarries(read.value.type)) return read
   return { fault: unsupportedNodeShape(`the carry fence names a type its info string carries: spell it ${carryFencePrefix}${read.value.type}`) }

src/markdown/parse/inline-content.ts

@@ -10,7 +10,7 @@ import { commonMarkLink, linkHref } from '../mark-spellings.ts'
 import { delimiterFlags, matchEmphasis, runLength } from '../commonmark/emphasis-matching.ts'
 import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { highlightDelimiter, highlightFlanking } from '../plain-conventions.ts'
-import { identicalMarks, nodeAttrs, nodeMarks } from '../../adf/document.ts'
+import { identicalMarks, mergeAdjacentText, nodeAttrs, nodeMarks } from '../../adf/document.ts'
 import { inlineNodeModel } from '../../adf/inline-nodes.ts'
 import { noSpans, readInlineDirective } from '../directive-syntax.ts'
 import { normalizeLabel, readInlineTarget, readLabel } from '../commonmark/link-syntax.ts'
@@ -23,6 +23,13 @@ import { readsAsOne, textBreakName, textBreakSpelling } from '../text-break.ts'
 
 export type InlineContent = { carry?: undefined; image: AdfNode; nodes?: undefined } | { carry: boolean; image?: undefined; nodes: AdfNode[] }
 
+// The text break leaf: it holds no marks, and stands between the nodes it parts until the outermost content checks and drops it.
+type TextBreak = { kind: 'textBreak' }
+
+type Inline = AdfNode | TextBreak
+
+type Scanned = { carry?: undefined; image: AdfNode; nodes?: undefined } | { carry: boolean; image?: undefined; nodes: Inline[] }
+
 export type LinkDefinitions = ReadonlyMap<string, LinkDefinition>
 
 type Bracket = { active: boolean; image: boolean; kind: 'open'; start: number }
@@ -34,10 +41,10 @@ type Pairing = EmphasisPairing<Run>
 // A carry piece holds a node whose marks are its own: an opaque carry, or an inline node spelling marks=empty.
 type Piece =
   | Bracket
-  | { kind: 'break' }
   | { kind: 'carry'; node: AdfNode }
   | { alt: string; kind: 'image'; node: AdfNode }
-  | { kind: 'nodes'; nodes: AdfNode[] }
+  | { kind: 'nodes'; nodes: Inline[] }
+  | TextBreak
   | { canClose: boolean; canOpen: boolean; character: string; kind: 'run'; length: number }
   | { closes: boolean; kind: 'highlight'; opens: boolean }
 
@@ -45,14 +52,14 @@ type Run = { canClose: boolean; canOpen: boolean; character: string; index: numb
 
 // `container` is `undefined` inside a directive's content slot, the emitter's `bracketed`.
 type Scan = {
-  // Nodes a carry piece restored: they never merge, and only identity tells a carried textBreak from the leaf.
-  carried: Set<AdfNode>
   container: LineContainer | undefined
   // Pieces below this have been walked for openers to deactivate: an image close folds the link-marked piece into alt text, leaving this the only record that the brackets around it are doomed.
   deactivatedBefore: number
   definitions: LinkDefinitions
   highlights: boolean
   openingSpellableLink: boolean
+  // The nodes carry pieces hold: none joins its neighbour.
+  ownMarks: Set<AdfNode>
   path: ConvertErrorPath
   pending: string
   pieces: Piece[]
@@ -60,7 +67,7 @@ type Scan = {
   spans: NestedSpans
 }
 
-type SlotContent = { carry: boolean; nodes: AdfNode[] }
+type SlotContent = { carry: boolean; nodes: Inline[] }
 
 const carriedInMark = 'no mark spelling wraps an opaque carry or an inline node spelling marks=empty: its marks are its own'
 const editorHighlight: AdfMark = { attrs: { color: '#f8e6a0' }, type: 'backgroundColor' }
@@ -68,13 +75,26 @@ const hreflessLink = 'the link mark spells its href: this one spells none'
 const imageAlone = 'an image fits only as a paragraph of its own: this one sits inside other content'
 const linkInLink = 'no link wraps a link: the [content] this one marks already holds one'
 const spellableLink = 'link takes the directive form only where CommonMark cannot spell it: this one it can, as [text](url "title") or <url>'
+const textBreak: TextBreak = { kind: 'textBreak' }
 
+// The outermost content: only here does a text break see both its neighbours.
 export function parseInlineContent(source: string, definitions: LinkDefinitions, path: ConvertErrorPath, container: LineContainer, flavour: Flavour): Result<InlineContent> {
-  return parseInline(source, { carried: new Set(), container, definitions, highlights: flavour === 'plain', path, spans: noSpans })
+  const scan: Scan = { container, deactivatedBefore: 0, definitions, highlights: flavour === 'plain', openingSpellableLink: false, ownMarks: new Set(), path, pending: '', pieces: [], source, spans: noSpans }
+  const scanned = scanInline(scan)
+  if (!scanned.ok) return scanned
+  if (scanned.value.image !== undefined) return success({ image: scanned.value.image })
+  const nodes = partText(scanned.value.nodes, scan)
+  if (!nodes.ok) return nodes
+  if (scan.openingSpellableLink) {
+    const takesDirective = openingLinkTakesDirective(nodes.value, path)
+    if (!takesDirective.ok) return takesDirective
+    if (!takesDirective.value) return failure('unsupported-node-shape', spellableLink, path)
+  }
+  return success({ carry: scanned.value.carry, nodes: nodes.value })
 }
 
-function parseInline(source: string, context: Pick<Scan, 'carried' | 'container' | 'definitions' | 'highlights' | 'path' | 'spans'>): Result<InlineContent> {
+function scanInline(scan: Scan): Result<Scanned> {
-  const scan: Scan = { ...context, deactivatedBefore: 0, openingSpellableLink: false, pending: '', pieces: [], source }
+  const { source } = scan
   let index = 0
   while (index < source.length) {
     switch (source.charAt(index)) {
@@ -211,7 +231,7 @@ function directivePiece(scan: Scan, span: DirectiveSpan, index: number): Result<
     if (carried.fault !== undefined) return faulted(carried.fault, scan.path)
     return success(carryPiece(scan, carried.value))
   }
-  if (span.name === textBreakName) return span.content === undefined && span.attributes.size === 0 ? success({ kind: 'break' }) : failure('unsupported-node-shape', `${textBreakName} spells the bare leaf form, ${textBreakSpelling}: this one spells more`, scan.path)
+  if (span.name === textBreakName) return span.content === undefined && span.attributes.size === 0 ? success(textBreak) : failure('unsupported-node-shape', `${textBreakName} spells the bare leaf form, ${textBreakSpelling}: this one spells more`, scan.path)
   const text = readTextDirective(span)
   if (text?.fault !== undefined) return faulted(text.fault, scan.path)
   if (text !== undefined) return success({ kind: 'nodes', nodes: [{ text: text.value, type: 'text' }] })
@@ -219,13 +239,15 @@ function directivePiece(scan: Scan, span: DirectiveSpan, index: number): Result<
   if (!slot.ok) return slot
   const mark = readDirectiveMark(span.name, span.attributes, scan.path)
   if (mark !== undefined) return mark.ok ? directiveMarkPiece(scan, span.name, mark.value, slot.value, index) : mark
-  const node = readInlineDirectiveNode(span.name, span.attributes, slot.value?.nodes, scan.path)
+  const content = slot.value?.nodes
+  if (content?.some(isTextBreak) === true) return failure('unsupported-node-shape', `${textBreakName} parts two text nodes: a content slot holds plain text`, scan.path)
+  const node = readInlineDirectiveNode(span.name, span.attributes, content === undefined ? undefined : adfNodes(content), scan.path)
   if (!node.ok) return node
   return success(node.value.marks === undefined ? { kind: 'nodes', nodes: [node.value] } : carryPiece(scan, node.value))
 }
 
 function carryPiece(scan: Scan, node: AdfNode): Piece {
-  scan.carried.add(node)
+  scan.ownMarks.add(node)
   return { kind: 'carry', node }
 }
 
@@ -240,11 +262,11 @@ function directiveMarkPiece(scan: Scan, name: string, mark: AdfMark, slot: SlotC
 }
 
 // spec/flavour.md, Marks. A link opening a paragraph may still need the directive form for the line it opens, which `assemble` asks the emitter.
-function refuseLinkDirective(scan: Scan, mark: AdfMark, nodes: readonly AdfNode[], index: number): Result<Piece> | undefined {
+function refuseLinkDirective(scan: Scan, mark: AdfMark, nodes: readonly Inline[], index: number): Result<Piece> | undefined {
   const href = linkHref(nodeAttrs(mark))
   if (href === undefined) return failure('unsupported-node-shape', hreflessLink, scan.path)
   if (marksLink(nodes)) return failure('unsupported-node-shape', linkInLink, scan.path)
-  if (commonMarkLink(nodeAttrs(mark), href, nodes, 0, scan.container === undefined) === undefined) return undefined
+  if (commonMarkLink(nodeAttrs(mark), href, adfNodes(nodes), 0, scan.container === undefined) === undefined) return undefined
   if (index !== 0 || scan.container !== 'paragraph') return failure('unsupported-node-shape', spellableLink, scan.path)
   scan.openingSpellableLink = true
   return undefined
@@ -252,7 +274,7 @@ function refuseLinkDirective(scan: Scan, mark: AdfMark, nodes: readonly AdfNode[
 
 function slotContent(scan: Scan, span: DirectiveSpan): Result<SlotContent | undefined> {
   if (span.content === undefined) return success(undefined)
-  const parsed = parseInline(span.content, { ...scan, container: undefined, highlights: false, spans: span.spans })
+  const parsed = scanInline({ ...scan, container: undefined, deactivatedBefore: 0, highlights: false, openingSpellableLink: false, pending: '', pieces: [], source: span.content, spans: span.spans })
   if (!parsed.ok) return parsed
   if (parsed.value.image !== undefined) return failure('unmappable-image', imageAlone, scan.path)
   return success(parsed.value)
@@ -268,40 +290,44 @@ function pushNode(scan: Scan, node: AdfNode): void {
   scan.pieces.push({ kind: 'nodes', nodes: [node] })
 }
 
-function assemble(scan: Scan): Result<InlineContent> {
+function assemble(scan: Scan): Result<Scanned> {
   const only = scan.pieces[0]
   if (scan.pieces.length === 1 && only?.kind === 'image') return success({ image: only.node })
   if (holdsImage(scan.pieces)) return failure('unmappable-image', imageAlone, scan.path)
-  const resolved = resolveNodes(scan.pieces, scan, true)
+  const nodes = resolveNodes(scan.pieces, scan, true)
-  const nodes = resolved.ok && scan.container !== undefined ? partText(resolved.value, scan) : resolved
   if (!nodes.ok) return nodes
-  if (scan.openingSpellableLink) {
-    const takesDirective = openingLinkTakesDirective(nodes.value, scan.path)
-    if (!takesDirective.ok) return takesDirective
-    if (!takesDirective.value) return failure('unsupported-node-shape', spellableLink, scan.path)
-  }
   return success({ carry: holdsCarry(scan.pieces), nodes: nodes.value })
 }
 
 // spec/flavour.md, Inline nodes: the leaf builds no node, so only the pair it parts spells it.
-function partText(nodes: readonly AdfNode[], scan: Scan): Result<AdfNode[]> {
+function partText(items: readonly Inline[], scan: Scan): Result<AdfNode[]> {
   const parted: AdfNode[] = []
-  for (const [index, node] of nodes.entries()) {
+  for (const [index, item] of items.entries()) {
-    if (!isTextBreak(node, scan.carried)) {
+    if (!isTextBreak(item)) {
-      parted.push(node)
+      parted.push(item)
       continue
     }
-    const previous = nodes[index - 1]
+    const previous = items[index - 1]
-    const next = nodes[index + 1]
+    const next = items[index + 1]
-    if (previous === undefined || next === undefined || scan.carried.has(previous) || scan.carried.has(next) || !readsAsOne(previous, next)) {
+    if (previous === undefined || next === undefined || isTextBreak(previous) || isTextBreak(next) || !readJoins(scan)(previous, next)) {
       return failure('unsupported-node-shape', `${textBreakName} parts two text nodes CommonMark reads back as one: this one parts something else`, scan.path)
     }
   }
   return success(parted)
 }
 
-function isTextBreak(node: AdfNode, carried: ReadonlySet<AdfNode>): boolean {
+function readJoins(scan: Scan): (previous: AdfNode, node: AdfNode) => boolean {
-  return node.type === textBreakName && !carried.has(node)
+  return (previous, node) => !scan.ownMarks.has(previous) && !scan.ownMarks.has(node) && readsAsOne(previous, node)
+}
+
+function isTextBreak(item: Inline): item is TextBreak {
+  return 'kind' in item
+}
+
+function adfNodes(items: readonly Inline[]): AdfNode[] {
+  const nodes: AdfNode[] = []
+  for (const item of items) if (!isTextBreak(item)) nodes.push(item)
+  return nodes
 }
 
 function holdsCarry(pieces: readonly Piece[]): boolean {
@@ -317,8 +343,8 @@ function holdsLink(pieces: readonly Piece[]): boolean {
   return pieces.some((piece) => piece.kind === 'nodes' && marksLink(piece.nodes))
 }
 
-function marksLink(nodes: readonly AdfNode[]): boolean {
+function marksLink(nodes: readonly Inline[]): boolean {
-  return nodes.some((node) => nodeMarks(node).some((mark) => mark.type === 'link'))
+  return adfNodes(nodes).some((node) => nodeMarks(node).some((mark) => mark.type === 'link'))
 }
 
 function readDelimiterRun(scan: Scan, index: number): number {
@@ -455,8 +481,8 @@ function closeImage(scan: Scan, at: number, inner: readonly Piece[], definition:
 function imageAlt(inner: readonly Piece[], scan: Scan): Result<string> {
   const nodes = resolveNodes(inner, scan, false)
   if (!nodes.ok) return nodes
-  if (nodes.value.some((node) => isTextBreak(node, scan.carried))) return failure('unsupported-node-shape', `${textBreakName} parts two text nodes: an image description holds plain text`, scan.path)
+  if (nodes.value.some(isTextBreak)) return failure('unsupported-node-shape', `${textBreakName} parts two text nodes: an image description holds plain text`, scan.path)
-  return success(nodes.value.map(altText).join(''))
+  return success(adfNodes(nodes.value).map(altText).join(''))
 }
 
 // spec/flavour.md, The CommonMark image: the description's plain text, the content slot included.
@@ -468,35 +494,37 @@ function altText(node: AdfNode): string {
 }
 
 // An image's alt text is plain, so `highlights` is off there and every `==` stays text.
-function resolveNodes(pieces: readonly Piece[], scan: Scan, highlights: boolean): Result<AdfNode[]> {
+function resolveNodes(pieces: readonly Piece[], scan: Scan, highlights: boolean): Result<Inline[]> {
   const nodes = pieces.map(pieceNodes)
   const runs = delimiterRuns(pieces)
   const pairings = matchEmphasis(runs)
   writeUnpaired(nodes, runs, pairings)
   if (!markPairings(pieces, nodes, pairings)) return failure('unsupported-node-shape', carriedInMark, scan.path)
   markHighlights(pieces, nodes, highlights ? pairedHighlights(pieces, nodes) : [])
-  return success(mergeText(nodes.flat(), scan.carried))
+  return success(mergeText(nodes.flat(), readJoins(scan)))
 }
 
-function mergeText(nodes: readonly AdfNode[], carried: ReadonlySet<AdfNode>): AdfNode[] {
+// A text break is a wall: the text on either side joins only its own side.
-  const merged: AdfNode[] = []
+function mergeText(items: readonly Inline[], joins: (previous: AdfNode, node: AdfNode) => boolean): Inline[] {
-  for (const node of nodes) {
+  const merged: Inline[] = []
-    const previous = merged[merged.length - 1]
+  let run: AdfNode[] = []
-    if (previous !== undefined && !carried.has(previous) && !carried.has(node) && readsAsOne(previous, node)) {
+  for (const item of items) {
-      merged[merged.length - 1] = { ...previous, text: `${previous.text ?? ''}${node.text ?? ''}` }
+    if (!isTextBreak(item)) {
+      run.push(item)
       continue
     }
-    merged.push(node)
+    for (const node of mergeAdjacentText(run, joins)) merged.push(node)
+    merged.push(item)
+    run = []
   }
+  for (const node of mergeAdjacentText(run, joins)) merged.push(node)
   return merged
 }
 
 // Only `imageAlt` reaches the image arm: everywhere else an image amid other content is refused first.
 // A highlight delimiter holds an empty text node until it pairs, so the emphasis around it marks it.
-function pieceNodes(piece: Piece): AdfNode[] {
+function pieceNodes(piece: Piece): Inline[] {
   switch (piece.kind) {
-    case 'break':
-      return [{ type: textBreakName }]
     case 'carry':
       return [piece.node]
     case 'highlight':
@@ -509,6 +537,8 @@ function pieceNodes(piece: Piece): AdfNode[] {
       return bracketNodes(piece)
     case 'run':
       return []
+    case 'textBreak':
+      return [piece]
   }
 }
 
@@ -521,7 +551,7 @@ function delimiterRuns(pieces: readonly Piece[]): Run[] {
 }
 
 // A run gives its delimiters up from the head closing and the tail opening; what is left between them is text.
-function writeUnpaired(nodes: AdfNode[][], runs: readonly Run[], pairings: readonly Pairing[]): void {
+function writeUnpaired(nodes: Inline[][], runs: readonly Run[], pairings: readonly Pairing[]): void {
   const heads = new Map<Run, number>()
   const tails = new Map<Run, number>()
   for (const pairing of pairings) {
@@ -536,7 +566,7 @@ function writeUnpaired(nodes: AdfNode[][], runs: readonly Run[], pairings: reado
 }
 
 // Innermost pairing first, so prepending leaves the marks array outermost first (spec/flavour.md, Marks).
-function markPairings(pieces: readonly Piece[], nodes: AdfNode[][], pairings: readonly Pairing[]): boolean {
+function markPairings(pieces: readonly Piece[], nodes: Inline[][], pairings: readonly Pairing[]): boolean {
   for (const pairing of pairings) {
     const mark: AdfMark = { type: markType(pairing.opener.character, pairing.used) }
     for (let index = pairing.opener.index + 1; index < pairing.closer.index; index += 1) {
@@ -547,12 +577,12 @@ function markPairings(pieces: readonly Piece[], nodes: AdfNode[][], pairings: re
   return true
 }
 
-function highlightDelimiters(pieces: readonly Piece[], nodes: readonly AdfNode[][]): HighlightDelimiter[] {
+function highlightDelimiters(pieces: readonly Piece[], nodes: readonly Inline[][]): HighlightDelimiter[] {
   const found: HighlightDelimiter[] = []
   let line = 0
   let position = 0
   for (const [index, piece] of pieces.entries()) {
-    const held = nodes[index] ?? []
+    const held = adfNodes(nodes[index] ?? [])
     const [holder] = held
     if (piece.kind === 'highlight' && holder !== undefined) {
       found.push({ closes: piece.closes, holder, index, line, opens: piece.opens, position })
@@ -568,7 +598,7 @@ function highlightDelimiters(pieces: readonly Piece[], nodes: readonly AdfNode[]
 }
 
 // Each opener takes the next closer holding at least one character after it, both in one line and under the same marks.
-function pairedHighlights(pieces: readonly Piece[], nodes: readonly AdfNode[][]): { closer: number; opener: number }[] {
+function pairedHighlights(pieces: readonly Piece[], nodes: readonly Inline[][]): { closer: number; opener: number }[] {
   const found = highlightDelimiters(pieces, nodes)
   const paired: { closer: number; opener: number }[] = []
   let closer = 0
@@ -579,7 +609,7 @@ function pairedHighlights(pieces: readonly Piece[], nodes: readonly AdfNode[][])
     let candidate = found[closer]
     while (candidate !== undefined && (!candidate.closes || candidate.position < earliest)) candidate = found[(closer += 1)]
     if (candidate === undefined) break
-    if (candidate.line !== opener.line || !identicalMarks(opener.holder, candidate.holder)) continue
+    if (candidate.line !== opener.line || !identicalMarks(nodeMarks(opener.holder), nodeMarks(candidate.holder))) continue
     paired.push({ closer: candidate.index, opener: opener.index })
     resume = candidate.position + highlightDelimiter.length
   }
@@ -587,9 +617,9 @@ function pairedHighlights(pieces: readonly Piece[], nodes: readonly AdfNode[][])
 }
 
 // Atlassian's schema refuses a highlight on code, a node holds one highlight, and a rebuilt node would lose its attributes.
-function markHighlights(pieces: readonly Piece[], nodes: AdfNode[][], paired: readonly { closer: number; opener: number }[]): void {
+function markHighlights(pieces: readonly Piece[], nodes: Inline[][], paired: readonly { closer: number; opener: number }[]): void {
   for (const [index, piece] of pieces.entries()) {
-    if (piece.kind === 'highlight') nodes[index] = (nodes[index] ?? []).map((holder) => ({ ...holder, text: highlightDelimiter }))
+    if (piece.kind === 'highlight') nodes[index] = adfNodes(nodes[index] ?? []).map((holder) => ({ ...holder, text: highlightDelimiter }))
   }
   for (const { closer, opener } of paired) {
     nodes[opener] = []
@@ -598,7 +628,8 @@ function markHighlights(pieces: readonly Piece[], nodes: AdfNode[][], paired: re
   }
 }
 
-function highlighted(node: AdfNode): AdfNode {
+function highlighted(node: Inline): Inline {
+  if (isTextBreak(node)) return node
   const marks = nodeMarks(node)
   if (node.type !== 'text' || Object.keys(nodeAttrs(node)).length > 0 || marks.some((mark) => mark.type === 'code' || mark.type === 'backgroundColor')) return node
   return { ...node, marks: [editorHighlight, ...marks] }
@@ -610,8 +641,9 @@ function markType(character: string, used: number): string {
 }
 
 // A node cannot carry one mark type twice (docs/decisions.md §No schema validation).
-function applyMark(nodes: readonly AdfNode[], mark: AdfMark): AdfNode[] {
+function applyMark(nodes: readonly Inline[], mark: AdfMark): Inline[] {
   return nodes.map((node) => {
+    if (isTextBreak(node)) return node
     const marks = nodeMarks(node)
     return marks.some((carried) => carried.type === mark.type) ? node : { ...node, marks: [mark, ...marks] }
   })

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

@@ -375,6 +375,8 @@ test('reads the carry fence back to the node its info string names and its JSON
   )
   assert.equal(content(markdownToAdf('```adf:\n{\n  "type": "blockCard"\n}\n```\n')), 'unsupported-node-shape: the carry fence names a type its info string carries: spell it adf:blockCard')
   assert.equal(content(markdownToAdf('```adf:\n{}\n```\n')), "unsupported-node-shape: the opaque carry holds one ADF node's JSON: this JSON is no ADF node")
+  const unnamed = 'unsupported-node-shape: the carry fence names a type no info string carries back: spell it adf: with the type in the JSON'
+  assert.equal(content(markdownToAdf('```adf:\\\\\n{}\n```\n')), unnamed)
 })
 
 test('reads the inline carry back to the node its json attribute holds', () => {
@@ -1076,3 +1078,17 @@ test('names the directive mark left without the content it wraps', () => {
   assert.equal(content(markdownToAdf('!adf:underline[]\n')), named)
   assert.equal(content(markdownToAdf('!adf:underline{}\n')), named)
 })
+
+test('reads the text break only between two text nodes CommonMark joins, building no node', () => {
+  assert.deepEqual(content(markdownToAdf('a!adf:textBreak{}b\n')), [{ content: [text('a'), text('b')], type: 'paragraph' }])
+  assert.deepEqual(content(markdownToAdf('==a!adf:textBreak{}b==\n')), [{ content: [text('==a'), text('b==')], type: 'paragraph' }])
+  const parts = 'unsupported-node-shape: textBreak parts two text nodes CommonMark reads back as one: this one parts something else'
+  const carried = '!adf:carry{json="{\\"text\\":\\"b\\",\\"type\\":\\"text\\"}"}'
+  for (const markdown of ['!adf:textBreak{}a\n', 'a!adf:textBreak{}\n', 'a!adf:textBreak{}!adf:textBreak{}b\n', '**a**!adf:textBreak{}b\n', '[!adf:textBreak{}](/u)\n', `a!adf:textBreak{}${carried}\n`]) {
+    assert.equal(content(markdownToAdf(markdown)), parts, markdown)
+  }
+  assert.equal(content(markdownToAdf('!adf:status[a!adf:textBreak{}b]\n')), 'unsupported-node-shape: textBreak parts two text nodes: a content slot holds plain text')
+  assert.equal(content(markdownToAdf('![a!adf:textBreak{}b](/i)\n')), 'unsupported-node-shape: textBreak parts two text nodes: an image description holds plain text')
+  assert.equal(content(markdownToAdf('a!adf:textBreak{x=y}b\n')), 'unsupported-node-shape: textBreak spells the bare leaf form, !adf:textBreak{}: this one spells more')
+  assert.deepEqual(content(markdownToAdf('!adf:carry{json="{\\"type\\":\\"textBreak\\"}"}\n')), [{ content: [{ type: 'textBreak' }], type: 'paragraph' }])
+})

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

@@ -6,7 +6,6 @@ import { adfToMarkdown } from '../emit/adf-to-markdown.ts'
 import { adfToPlainMarkdown } from '../emit/plain-reduction.ts'
 import { largestNesting } from '../../nesting.ts'
 import { markdownToAdf, plainMarkdownToAdf } from './markdown-to-adf.ts'
-import { toEditorNormal } from '../../adf/editor-normal.ts'
 
 const code: AdfMark = { type: 'code' }
 const em: AdfMark = { type: 'em' }
@@ -18,7 +17,7 @@ const taskTypes = ['blockTaskItem', 'taskItem', 'taskList']
 function read(markdown: string): readonly AdfNode[] | string {
   const parsed = plainMarkdownToAdf(markdown)
   if (!parsed.ok) return parsed.error.code
-  const blocks = toEditorNormal(parsed.value).content ?? []
+  const blocks = parsed.value.content ?? []
   const pending = [...blocks]
   for (let block = pending.pop(); block !== undefined; block = pending.pop()) {
     for (const child of block.content ?? []) pending.push(child)
@@ -31,8 +30,8 @@ function read(markdown: string): readonly AdfNode[] | string {
   return blocks
 }
 
-function normal(...blocks: AdfNode[]): readonly AdfNode[] {
+function blocks(...content: AdfNode[]): readonly AdfNode[] {
-  return toEditorNormal(document(...blocks)).content ?? []
+  return content
 }
 
 function document(...content: AdfNode[]): AdfDocument {
@@ -57,7 +56,7 @@ function bare(type: string, ...content: AdfNode[]): AdfNode {
 }
 
 function paragraph(...content: AdfNode[]): AdfNode {
-  return bare('paragraph', ...content)
+  return content.length === 0 ? { type: 'paragraph' } : bare('paragraph', ...content)
 }
 
 function said(value: string): AdfNode {
@@ -101,7 +100,7 @@ test('reads the rest of an alert marker line as the panel first body paragraph,
   assert.deepEqual(read('> [!tip] Title\n> body\n'), [panel('tip', said('Title'), said('body'))])
   assert.deepEqual(read('> [!tip] Title\\\n> body\n'), [panel('tip', said('Title'), said('body'))])
   assert.deepEqual(read('> [!NOTE]\\\n> Broken.\n'), [panel('info', said('Broken.'))])
-  assert.deepEqual(read('> [!NOTE]\n'), normal(panel('info', paragraph())))
+  assert.deepEqual(read('> [!NOTE]\n'), blocks(panel('info', paragraph())))
   assert.deepEqual(read('> > [!WARNING]\n> > Inner.\n'), [bare('blockquote', panel('warning', said('Inner.')))])
 })
 
@@ -120,27 +119,27 @@ test('reads a folded callout to an expand titled by the rest of its marker line,
     node('expand', { title: 'Why?' }, paragraph(text('See '), text('the docs', link), text(', '), text('now', strong), text('.'))),
   ])
   assert.deepEqual(read('> [!NOTE]- Two\\\n> lines\n'), [node('expand', { title: 'Two' }, said('lines'))])
-  assert.deepEqual(read('> [!faq]- See [x](http://y)\n'), normal(node('expand', { title: 'See x (http://y)' }, paragraph())))
+  assert.deepEqual(read('> [!faq]- See [x](http://y)\n'), blocks(node('expand', { title: 'See x (http://y)' }, paragraph())))
-  assert.deepEqual(read('> [!faq]- [a **b**](u "t")[c](u) and [d](v)\n'), normal(node('expand', { title: 'a bc (u) and d (v)' }, paragraph())))
+  assert.deepEqual(read('> [!faq]- [a **b**](u "t")[c](u) and [d](v)\n'), blocks(node('expand', { title: 'a bc (u) and d (v)' }, paragraph())))
-  assert.deepEqual(read('> [!faq]- <http://y> or <a@b.c> or <http://a\\b>\n'), normal(node('expand', { title: 'http://y or a@b.c or http://a\\b' }, paragraph())))
+  assert.deepEqual(read('> [!faq]- <http://y> or <a@b.c> or <http://a\\b>\n'), blocks(node('expand', { title: 'http://y or a@b.c or http://a\\b' }, paragraph())))
-  assert.deepEqual(read('> [!faq]- [a&#10;b](u)\n'), normal(node('expand', { title: 'a\nb (u)' }, paragraph())))
+  assert.deepEqual(read('> [!faq]- [a&#10;b](u)\n'), blocks(node('expand', { title: 'a\nb (u)' }, paragraph())))
-  assert.deepEqual(read('> [!faq]- [!adf:mention[@M]{id=5}](u) !adf:inlineCard{url="http://y"}\n'), normal(node('expand', { title: '@M (u) http://y' }, paragraph())))
+  assert.deepEqual(read('> [!faq]- [!adf:mention[@M]{id=5}](u) !adf:inlineCard{url="http://y"}\n'), blocks(node('expand', { title: '@M (u) http://y' }, paragraph())))
-  assert.deepEqual(read('> [!NOTE]- Set ==x== here\n'), normal(node('expand', { title: 'Set ==x== here' }, paragraph())))
+  assert.deepEqual(read('> [!NOTE]- Set ==x== here\n'), blocks(node('expand', { title: 'Set ==x== here' }, paragraph())))
   assert.deepEqual(read('> [!NOTE]-\n>\n> Line.\n'), [bare('expand', said('Line.'))])
 })
 
 test('reads a folded callout inside an expand to a nested expand', () => {
   const markdown = '> [!NOTE]- Outer\n>\n> > [!NOTE]- Inner\n> >\n> > Deep.\n>\n> > [!TIP]\n> >\n> > > [!NOTE]-\n'
-  assert.deepEqual(read(markdown), normal(node('expand', { title: 'Outer' }, node('nestedExpand', { title: 'Inner' }, said('Deep.')), panel('tip', bare('nestedExpand', paragraph())))))
+  assert.deepEqual(read(markdown), blocks(node('expand', { title: 'Outer' }, node('nestedExpand', { title: 'Inner' }, said('Deep.')), panel('tip', bare('nestedExpand', paragraph())))))
-  assert.deepEqual(read('- > [!NOTE]-\n'), normal(bare('bulletList', bare('listItem', bare('expand', paragraph())))))
+  assert.deepEqual(read('- > [!NOTE]-\n'), blocks(bare('bulletList', bare('listItem', bare('expand', paragraph())))))
-  assert.deepEqual(read('!adf:expand\n> [!NOTE]- Inner\n!adf:/expand\n'), normal(bare('expand', node('nestedExpand', { title: 'Inner' }, paragraph()))))
+  assert.deepEqual(read('!adf:expand\n> [!NOTE]- Inner\n!adf:/expand\n'), blocks(bare('expand', node('nestedExpand', { title: 'Inner' }, paragraph()))))
 })
 
 test('reads a bullet list whose every item leads with a task marker to a task list', () => {
   assert.deepEqual(read('- [x] Write the spec\n- [ ] Ship **it**\n- [X] Tell\n'), [
     bare('taskList', task('DONE', text('Write the spec')), task('TODO', text('Ship '), text('it', strong)), task('DONE', text('Tell'))),
   ])
-  assert.deepEqual(read('- [x]\n- [ ]\\\n  after\n'), normal(bare('taskList', task('DONE'), task('TODO', text('after')))))
+  assert.deepEqual(read('- [x]\n- [ ]\\\n  after\n'), blocks(bare('taskList', task('DONE'), task('TODO', text('after')))))
   const minted = plainMarkdownToAdf('- [x] Parent\n  - [ ] Child\n')
   assert.deepEqual(minted.ok ? minted.value.content : minted.error.code, [
     node(
@@ -202,7 +201,7 @@ test('reads what the reduction wrote back to the node it reduced, less the attri
     assert.deepEqual(roundTripped(node('panel', { localId, panelType }, said('Check.'))), [panel(panelType, said('Check.'))], panelType)
   }
   const expand = node('expand', { localId, title: 'Log' }, said('Line.'), node('nestedExpand', { title: 'Inner' }, said('Deep.')))
-  assert.deepEqual(roundTripped(node('panel', { panelType: 'tip' }, paragraph()), node('expand', { title: 'Empty' }, paragraph())), normal(panel('tip', paragraph()), node('expand', { title: 'Empty' }, paragraph())))
+  assert.deepEqual(roundTripped(node('panel', { panelType: 'tip' }, paragraph()), node('expand', { title: 'Empty' }, paragraph())), blocks(panel('tip', paragraph()), node('expand', { title: 'Empty' }, paragraph())))
   assert.deepEqual(roundTripped(expand), [node('expand', { title: 'Log' }, said('Line.'), node('nestedExpand', { title: 'Inner' }, said('Deep.')))])
   const tasks = bare(
     'taskList',

src/markdown/text-break.ts

@@ -1,5 +1,5 @@
 import type { AdfNode } from '../adf/document.ts'
-import { identicalMarks } from '../adf/document.ts'
+import { identicalMarks, nodeMarks } from '../adf/document.ts'
 import { spellInlineLeafDirective } from './directive-syntax.ts'
 
 export const textBreakName = 'textBreak'
@@ -8,7 +8,7 @@ export const textBreakSpelling = spellInlineLeafDirective(textBreakName, '')
 
 // Whether CommonMark reads the pair back as one text node, where neither rides the carry (spec/flavour.md, Inline nodes).
 export function readsAsOne(previous: AdfNode, node: AdfNode): boolean {
-  return spelledAsText(previous) && spelledAsText(node) && identicalMarks(previous, node)
+  return spelledAsText(previous) && spelledAsText(node) && identicalMarks(nodeMarks(previous), nodeMarks(node))
 }
 
 function spelledAsText(node: AdfNode): boolean {

todo.md

@@ -6,7 +6,7 @@
 
 `Bar = 9`
 
-`Next ID = 54`
+`Next ID = 55`
 
 | Goal | W |
 |---|---|
@@ -31,6 +31,7 @@
 | 49 | 0.2.0 |  | **Read a list whose bullet or ordered delimiter changes as two lists in the CommonMark reader.** | 4 | 5 | 5 | 8 | 3, 4 | 17.2 |
 | 52 | 0.2.0 |  | **Spell `colwidth` as a comma list, `colwidth="340,420"`.** | 3 | 3 | 5 | 6 | 5 | 13.0 |
 | 51 | 0.2.0 |  | **Match a reference label to its definition under Unicode case folding.** | 2 | 2 | 2 | 7 | 3, 4 | 12.4 |
+| 54 | 0.2.0 |  | **Make `docs/decisions.md` §The source parts by ADF and format name every import `parse/` takes from `emit/`.** | 2 | 2 | 2 | 5 | 1 | 11.5 |
 | 53 | 0.2.0 |  | **Bench a block's `marks` spelling with the writer panel and adopt its pick.** | 4 | 5 | 5 | 6 | 5 | 11.5 |
 | 50 | 0.2.0 |  | **Read `[](/url)` and `[]()` as CommonMark's empty link.** | 4 | 4 | 3 | 6 | 3, 4, 6 | 10.4 |
 | 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 |
@@ -95,6 +96,12 @@ 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.
 
+### 54. Make `docs/decisions.md` §The source parts by ADF and format name every import `parse/` takes from `emit/`.
+
+The entry says `parse/` imports only `commonMarkSpelling` and `openingLinkTakesDirective` from
+`emit/`; `parse/markdown-to-adf.ts` also imports `inlineLeaves` from `emit/plain-inline.ts`. Either
+the entry names it with its reason, or the reader stops importing it.
+
 ### 53. Bench a block's `marks` spelling with the writer panel and adopt its pick.
 
 Today `marks="[{\"attrs\":{\"mode\":\"wide\"},\"type\":\"breakout\"}]"`, the marks array as