Add associationId helper to state

lib/handle/definition.js

@@ -5,7 +5,6 @@
  * @typedef {import('../types.js').Info} Info
  */
 
-import {association} from '../util/association.js'
 import {checkQuote} from '../util/check-quote.js'
 
 /**
@@ -23,7 +22,7 @@ export function definition(node, _, state, info) {
   const tracker = state.createTracker(info)
   let value = tracker.move('[')
   value += tracker.move(
-    state.safe(association(node), {
+    state.safe(state.associationId(node), {
       before: value,
       after: ']',
       ...tracker.current()

lib/handle/image-reference.js

@@ -5,8 +5,6 @@
  * @typedef {import('../types.js').Info} Info
  */
 
-import {association} from '../util/association.js'
-
 imageReference.peek = imageReferencePeek
 
 /**
@@ -38,7 +36,7 @@ export function imageReference(node, _, state, info) {
   // up making a `shortcut` reference, because then there is no brace output.
   // Practically, in that case, there is no content, so it doesn’t matter that
   // we’ve tracked one too many characters.
-  const reference = state.safe(association(node), {
+  const reference = state.safe(state.associationId(node), {
     before: value,
     after: ']',
     ...tracker.current()

lib/handle/link-reference.js

@@ -5,8 +5,6 @@
  * @typedef {import('../types.js').Info} Info
  */
 
-import {association} from '../util/association.js'
-
 linkReference.peek = linkReferencePeek
 
 /**
@@ -38,7 +36,7 @@ export function linkReference(node, _, state, info) {
   // up making a `shortcut` reference, because then there is no brace output.
   // Practically, in that case, there is no content, so it doesn’t matter that
   // we’ve tracked one too many characters.
-  const reference = state.safe(association(node), {
+  const reference = state.safe(state.associationId(node), {
     before: value,
     after: ']',
     ...tracker.current()

lib/index.js

@@ -17,6 +17,7 @@ import {configure} from './configure.js'
 import {handle as handlers} from './handle/index.js'
 import {join} from './join.js'
 import {unsafe} from './unsafe.js'
+import {association} from './util/association.js'
 import {containerPhrasing} from './util/container-phrasing.js'
 import {containerFlow} from './util/container-flow.js'
 import {indentLines} from './util/indent-lines.js'
@@ -38,6 +39,7 @@ export function toMarkdown(tree, options = {}) {
   const state = {
     enter,
     indentLines,
+    associationId: association,
     containerPhrasing: containerPhrasingBound,
     containerFlow: containerFlowBound,
     createTracker: track,

lib/types.js

@@ -1,11 +1,12 @@
 /**
  * @typedef {import('unist').Parent} UnistParent
  * @typedef {import('unist').Point} Point
- * @typedef {import('mdast').Root} Root
+ * @typedef {import('mdast').Association} Association
  * @typedef {import('mdast').Content} Content
- * @typedef {import('mdast').TopLevelContent} TopLevelContent
  * @typedef {import('mdast').ListContent} ListContent
  * @typedef {import('mdast').PhrasingContent} PhrasingContent
+ * @typedef {import('mdast').Root} Root
+ * @typedef {import('mdast').TopLevelContent} TopLevelContent
  * @typedef {import('../index.js').ConstructName} ConstructName
  */
 
@@ -73,6 +74,28 @@
  * @returns {Tracker}
  *   Tracker.
  *
+ * @callback AssociationId
+ *   Get an identifier from an association to match it to others.
+ *
+ *   Associations are nodes that match to something else through an ID:
+ *   <https://github.com/syntax-tree/mdast#association>.
+ *
+ *   The `label` of an association is the string value: character escapes and
+ *   references work, and casing is intact.
+ *   The `identifier` is used to match one association to another:
+ *   controversially, character escapes and references don’t work in this
+ *   matching: `&copy;` does not match `©`, and `\+` does not match `+`.
+ *
+ *   But casing is ignored (and whitespace) is trimmed and collapsed: ` A\nb`
+ *   matches `a b`.
+ *   So, we do prefer the label when figuring out how we’re going to serialize:
+ *   it has whitespace, casing, and we can ignore most useless character
+ *   escapes and all character references.
+ * @param {Association} node
+ *   Node that includes an association.
+ * @returns {string}
+ *   ID.
+ *
  * @callback Map
  *   Map function to pad a single line.
  * @param {string} value
@@ -169,6 +192,8 @@
  *   Positions of child nodes in their parents.
  * @property {IndentLines} indentLines
  *   Pad serialized markdown.
+ * @property {AssociationId} associationId
+ *   Get an identifier from an association to match it to others.
  * @property {ContainerPhrasing} containerPhrasing
  *   Serialize the children of a parent that contains phrasing children.
  * @property {ContainerFlow} containerFlow

lib/util/association.js

@@ -1,23 +1,28 @@
 /**
- * @typedef {import('mdast').Association} Association
+ * @typedef {import('../types.js').AssociationId} AssociationId
  */
 
 import {decodeString} from 'micromark-util-decode-string'
 
 /**
+ * Get an identifier from an association to match it to others.
+ *
+ * Associations are nodes that match to something else through an ID:
+ * <https://github.com/syntax-tree/mdast#association>.
+ *
  * The `label` of an association is the string value: character escapes and
  * references work, and casing is intact.
- * The `identifier` is used to match one association to another: controversially,
- * character escapes and references don’t work in this matching: `&copy;` does
- * not match `©`, and `\+` does not match `+`.
+ * The `identifier` is used to match one association to another:
+ * controversially, character escapes and references don’t work in this
+ * matching: `&copy;` does not match `©`, and `\+` does not match `+`.
+ *
  * But casing is ignored (and whitespace) is trimmed and collapsed: ` A\nb`
  * matches `a b`.
  * So, we do prefer the label when figuring out how we’re going to serialize:
- * it has whitespace, casing, and we can ignore most useless character escapes
- * and all character references.
+ * it has whitespace, casing, and we can ignore most useless character
+ * escapes and all character references.
  *
- * @param {Association} node
- * @returns {string}
+ * @type {AssociationId}
  */
 export function association(node) {
   if (node.label || !node.identifier) {

readme.md

@@ -478,6 +478,9 @@ Info passed around about the current state (TypeScript type).
     — stack of constructs we’re in
 *   `indexStack` (`Array<number>`)
     — positions of child nodes in their parents
+*   `associationId` (`(node: Association) => string`)
+    — get an identifier from an association to match it to others (see
+    [`Association`][association])
 *   `enter` (`(construct: ConstructName) => () => void`)
     — enter a construct (returns a corresponding exit function)
     (see [`ConstructName`][constructname])
@@ -685,6 +688,8 @@ abide by its terms.
 
 [node]: https://github.com/syntax-tree/mdast#nodes
 
+[association]: https://github.com/syntax-tree/mdast#association
+
 [mdast-util-gfm]: https://github.com/syntax-tree/mdast-util-gfm
 
 [mdast-util-mdx]: https://github.com/syntax-tree/mdast-util-mdx