13b - link arm back in emitLink, one isBareLink, directiveMarkPiece, refusal names the spelling, spec subset section follows

src/markdown/emit/inline-line.ts

@@ -3,7 +3,7 @@ import type { InlineDirective } from '../../adf/inline-directives.ts'
 import { assembleInlineLine, isSyntax, type InlineEscaping, type InlineSegment, type LineContainer, type NodeRange } from './line-escaping.ts'
 import { carriedInline } from '../opaque-carry.ts'
 import { claimsLine, holdsNullCharacter } from '../commonmark-grammar.ts'
-import { commonMarkLink, markSpelling, spellMarkAttributes, type CommonMarkLink } from '../mark-spellings.ts'
+import { commonMarkLink, markSpelling, spellMarkAttributes } from '../mark-spellings.ts'
 import { escapeUnbalanced, spellDestination } from '../link-syntax.ts'
 import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { inlineDirective } from '../../adf/inline-directives.ts'
@@ -257,13 +257,8 @@ function emitMarkedRun(nodes: readonly AdfNode[], mark: AdfMark, depth: number,
   if (attributes === undefined) return success({ carry: range })
   if (spelling.kind === 'code') return emitCodeSpan(nodes, depth, range, path)
   if (spelling.kind === 'emphasis') return emitEmphasis(nodes, spelling.spelling, depth, range, context)
-  if (spelling.kind === 'link') {
-    const href = nodeAttrs(mark)['href']
-    if (typeof href !== 'string') return success({ carry: range })
-    const opening = depth === 0 && index === 0 && context.openingLinkAsDirective
-    const commonMark = opening ? undefined : commonMarkLink(nodeAttrs(mark), href, isBareLink(nodes, href, depth), context.bracketed)
-    if (commonMark !== undefined) return emitLink(nodes, href, commonMark, depth, range, context)
-  }
+  const link = spelling.kind === 'link' ? emitLink(nodes, mark, depth, range, context) : undefined
+  if (link !== undefined) return link
   const inner = emitRun(nodes, depth + 1, index, { ...context, bracketed: true, spansLines: false })
   if (!inner.ok) return inner
   if (inner.value.carry !== undefined) return inner
@@ -304,12 +299,13 @@ function needsPadding(text: string): boolean {
   return text.startsWith(' ') && text.endsWith(' ') && /[^ ]/.test(text)
 }
 
-function isBareLink(nodes: readonly AdfNode[], href: string, depth: number): boolean {
-  const node = nodes[0]
-  return nodes.length === 1 && node !== undefined && node.type === 'text' && node.text === href && nodeMarks(node).length === depth + 1
-}
-
-function emitLink(nodes: readonly AdfNode[], href: string, commonMark: CommonMarkLink, depth: number, range: NodeRange, context: InlineContext): Result<Emission> {
+// `undefined` where the link takes the directive form the caller spells.
+function emitLink(nodes: readonly AdfNode[], mark: AdfMark, depth: number, range: NodeRange, context: InlineContext): Result<Emission> | undefined {
+  const href = nodeAttrs(mark)['href']
+  if (typeof href !== 'string') return success({ carry: range })
+  const opening = depth === 0 && range.first === 0 && context.openingLinkAsDirective
+  const commonMark = opening ? undefined : commonMarkLink(nodeAttrs(mark), href, nodes, depth + 1, context.bracketed)
+  if (commonMark === undefined) return undefined
   if (commonMark.form === 'autolink') return success({ segments: [syntax(`<${href}>`)] })
   const inner = emitRun(nodes, depth + 1, range.first, { ...context, bracketed: true })
   if (!inner.ok) return inner

src/markdown/mark-spellings.ts

@@ -1,4 +1,4 @@
-import type { AdfAttributes, AdfMark } from '../adf/document.ts'
+import type { AdfAttributes, AdfMark, AdfNode } from '../adf/document.ts'
 import type { AttributeVocabulary } from '../adf/attribute-vocabulary.ts'
 import type { MarkType } from '../adf/mark-attributes.ts'
 import { escapeUnbalanced, spellLinkTarget } from './link-syntax.ts'
@@ -6,7 +6,7 @@ import { holdsDirectivePrefix, spellAttributes, spellVocabulary } from './direct
 import { holdsEntityReference } from './entity-references.ts'
 import { isAutolink } from './commonmark-grammar.ts'
 import { isMarkType, markAttributes } from '../adf/mark-attributes.ts'
-import { nodeAttrs } from '../adf/document.ts'
+import { nodeAttrs, nodeMarks } from '../adf/document.ts'
 import { vocabularyPairs } from '../adf/attribute-vocabulary.ts'
 
 type Spelling = { kind: 'code' | 'directive' | 'link'; spelling?: undefined } | { kind: 'emphasis'; spelling: string }
@@ -35,16 +35,21 @@ export function markSpelling(type: string): MarkSpelling | undefined {
   return { attributes, kind: spelling.kind }
 }
 
-// spec/flavour.md, Marks. `bare`: one text node reading exactly `href`, the link innermost.
-export function commonMarkLink(attrs: AdfAttributes, href: string, bare: boolean, bracketed: boolean): CommonMarkLink | undefined {
+// spec/flavour.md, Marks. `marksInside` counts the marks the link's nodes carry within it: the emitter's depth, the parser's none.
+export function commonMarkLink(attrs: AdfAttributes, href: string, nodes: readonly AdfNode[], marksInside: number, bracketed: boolean): CommonMarkLink | undefined {
   if (Object.keys(attrs).some((key) => key !== 'href' && key !== 'title')) return undefined
   const title = attrs['title']
   const autolinkHolds = !bracketed || (!href.includes('`') && !holdsDirectivePrefix(href) && escapeUnbalanced(href, '[', ']') === href)
-  if (bare && autolinkHolds && title === undefined && isAutolink(href) && !holdsEntityReference(href)) return { form: 'autolink' }
+  if (isBareLink(nodes, href, marksInside) && autolinkHolds && title === undefined && isAutolink(href) && !holdsEntityReference(href)) return { form: 'autolink' }
   const target = spellLinkTarget(href, typeof title === 'string' ? title : undefined)
   return target === undefined ? undefined : { form: 'inline', target }
 }
 
+function isBareLink(nodes: readonly AdfNode[], href: string, marksInside: number): boolean {
+  const node = nodes[0]
+  return nodes.length === 1 && node !== undefined && node.type === 'text' && node.text === href && nodeMarks(node).length === marksInside
+}
+
 export function spellMarkAttributes(mark: AdfMark, vocabulary: AttributeVocabulary): string | undefined {
   const pairs = vocabularyPairs(nodeAttrs(mark), vocabulary, [])
   return pairs === undefined ? undefined : spellAttributes(spellVocabulary(pairs))

src/markdown/parse/inline-content.ts

@@ -51,7 +51,7 @@ type SlotContent = { carry: boolean; nodes: AdfNode[] }
 
 const carriedInMark = 'no mark spelling wraps an opaque carry: the carried node restores exactly, marks included'
 const imageAlone = 'an image fits only as a paragraph of its own: this one sits inside other content'
-const spellableLink = 'link takes the directive form only where CommonMark cannot spell it: this one it can'
+const spellableLink = 'link takes the directive form only where CommonMark cannot spell it: this one it can, as [text](url "title") or <url>'
 
 export function parseInlineContent(source: string, definitions: LinkDefinitions, path: ConvertErrorPath, container: LineContainer): Result<InlineContent> {
   return parseInline(source, definitions, path, container)
@@ -190,28 +190,27 @@ function directivePiece(scan: Scan, span: DirectiveSpan, index: number): Result<
   const slot = slotContent(scan, span.content)
   if (!slot.ok) return slot
   const mark = readDirectiveMark(span.name, span.attributes, scan.path)
-  if (mark !== undefined) {
-    if (!mark.ok) return mark
-    if (slot.value === undefined || slot.value.nodes.length === 0) {
-      return failure('unsupported-node-shape', `the ${span.name} mark wraps the [content] it marks: this one wraps none`, scan.path)
-    }
-    if (slot.value.carry) return failure('unsupported-node-shape', carriedInMark, scan.path)
-    const refused = mark.value.type === 'link' ? refuseSpellableLink(scan, mark.value, slot.value.nodes, index) : undefined
-    if (refused !== undefined) return refused
-    return success({ kind: 'nodes', nodes: applyMark(slot.value.nodes, mark.value) })
-  }
+  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)
   if (!node.ok) return node
   return success({ kind: 'nodes', nodes: [node.value] })
 }
 
+function directiveMarkPiece(scan: Scan, name: string, mark: AdfMark, slot: SlotContent | undefined, index: number): Result<Piece> {
+  if (slot === undefined || slot.nodes.length === 0) {
+    return failure('unsupported-node-shape', `the ${name} mark wraps the [content] it marks: this one wraps none`, scan.path)
+  }
+  if (slot.carry) return failure('unsupported-node-shape', carriedInMark, scan.path)
+  const refused = mark.type === 'link' ? refuseSpellableLink(scan, mark, slot.nodes, index) : undefined
+  if (refused !== undefined) return refused
+  return success({ kind: 'nodes', nodes: applyMark(slot.nodes, mark) })
+}
+
 // 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 refuseSpellableLink(scan: Scan, mark: AdfMark, nodes: readonly AdfNode[], index: number): Result<Piece> | undefined {
   const href = nodeAttrs(mark)['href']
   if (typeof href !== 'string') return undefined
-  const only = nodes[0]
-  const bare = nodes.length === 1 && only !== undefined && only.type === 'text' && only.text === href && nodeMarks(only).length === 0
-  if (commonMarkLink(nodeAttrs(mark), href, bare, scan.container === undefined) === undefined) return undefined
+  if (commonMarkLink(nodeAttrs(mark), href, 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

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

@@ -970,7 +970,7 @@ test('names the mark markdown spells, never a directive', () => {
 
 // spec/flavour.md, Marks: the directive link is refused wherever the emitter would pick the markdown spelling.
 test('refuses the directive link CommonMark could spell, and reads the one it could not', () => {
-  const refused = 'unsupported-node-shape: link takes the directive form only where CommonMark cannot spell it: this one it can'
+  const refused = 'unsupported-node-shape: link takes the directive form only where CommonMark cannot spell it: this one it can, as [text](url "title") or <url>'
   assert.equal(content(markdownToAdf('!adf:link[a]{href="/u"}\n')), refused)
   assert.equal(content(markdownToAdf('See !adf:link[a]{href="/u"}.\n')), refused)
   assert.equal(content(markdownToAdf('!adf:link[https://example.com/]{href="https://example.com/"}\n')), refused)