🎉 initiate project *astro_rewrite*

node_modules/micromark-core-commonmark/lib/attention.js

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+/**
+ * @typedef {import('micromark-util-types').Code} Code
+ * @typedef {import('micromark-util-types').Construct} Construct
+ * @typedef {import('micromark-util-types').Event} Event
+ * @typedef {import('micromark-util-types').Point} Point
+ * @typedef {import('micromark-util-types').Resolver} Resolver
+ * @typedef {import('micromark-util-types').State} State
+ * @typedef {import('micromark-util-types').Token} Token
+ * @typedef {import('micromark-util-types').TokenizeContext} TokenizeContext
+ * @typedef {import('micromark-util-types').Tokenizer} Tokenizer
+ */
+
+import {push, splice} from 'micromark-util-chunked'
+import {classifyCharacter} from 'micromark-util-classify-character'
+import {resolveAll} from 'micromark-util-resolve-all'
+/** @type {Construct} */
+export const attention = {
+  name: 'attention',
+  tokenize: tokenizeAttention,
+  resolveAll: resolveAllAttention
+}
+
+/**
+ * Take all events and resolve attention to emphasis or strong.
+ *
+ * @type {Resolver}
+ */
+function resolveAllAttention(events, context) {
+  let index = -1
+  /** @type {number} */
+  let open
+  /** @type {Token} */
+  let group
+  /** @type {Token} */
+  let text
+  /** @type {Token} */
+  let openingSequence
+  /** @type {Token} */
+  let closingSequence
+  /** @type {number} */
+  let use
+  /** @type {Array<Event>} */
+  let nextEvents
+  /** @type {number} */
+  let offset
+
+  // Walk through all events.
+  //
+  // Note: performance of this is fine on an mb of normal markdown, but it’s
+  // a bottleneck for malicious stuff.
+  while (++index < events.length) {
+    // Find a token that can close.
+    if (
+      events[index][0] === 'enter' &&
+      events[index][1].type === 'attentionSequence' &&
+      events[index][1]._close
+    ) {
+      open = index
+
+      // Now walk back to find an opener.
+      while (open--) {
+        // Find a token that can open the closer.
+        if (
+          events[open][0] === 'exit' &&
+          events[open][1].type === 'attentionSequence' &&
+          events[open][1]._open &&
+          // If the markers are the same:
+          context.sliceSerialize(events[open][1]).charCodeAt(0) ===
+            context.sliceSerialize(events[index][1]).charCodeAt(0)
+        ) {
+          // If the opening can close or the closing can open,
+          // and the close size *is not* a multiple of three,
+          // but the sum of the opening and closing size *is* multiple of three,
+          // then don’t match.
+          if (
+            (events[open][1]._close || events[index][1]._open) &&
+            (events[index][1].end.offset - events[index][1].start.offset) % 3 &&
+            !(
+              (events[open][1].end.offset -
+                events[open][1].start.offset +
+                events[index][1].end.offset -
+                events[index][1].start.offset) %
+              3
+            )
+          ) {
+            continue
+          }
+
+          // Number of markers to use from the sequence.
+          use =
+            events[open][1].end.offset - events[open][1].start.offset > 1 &&
+            events[index][1].end.offset - events[index][1].start.offset > 1
+              ? 2
+              : 1
+          const start = Object.assign({}, events[open][1].end)
+          const end = Object.assign({}, events[index][1].start)
+          movePoint(start, -use)
+          movePoint(end, use)
+          openingSequence = {
+            type: use > 1 ? 'strongSequence' : 'emphasisSequence',
+            start,
+            end: Object.assign({}, events[open][1].end)
+          }
+          closingSequence = {
+            type: use > 1 ? 'strongSequence' : 'emphasisSequence',
+            start: Object.assign({}, events[index][1].start),
+            end
+          }
+          text = {
+            type: use > 1 ? 'strongText' : 'emphasisText',
+            start: Object.assign({}, events[open][1].end),
+            end: Object.assign({}, events[index][1].start)
+          }
+          group = {
+            type: use > 1 ? 'strong' : 'emphasis',
+            start: Object.assign({}, openingSequence.start),
+            end: Object.assign({}, closingSequence.end)
+          }
+          events[open][1].end = Object.assign({}, openingSequence.start)
+          events[index][1].start = Object.assign({}, closingSequence.end)
+          nextEvents = []
+
+          // If there are more markers in the opening, add them before.
+          if (events[open][1].end.offset - events[open][1].start.offset) {
+            nextEvents = push(nextEvents, [
+              ['enter', events[open][1], context],
+              ['exit', events[open][1], context]
+            ])
+          }
+
+          // Opening.
+          nextEvents = push(nextEvents, [
+            ['enter', group, context],
+            ['enter', openingSequence, context],
+            ['exit', openingSequence, context],
+            ['enter', text, context]
+          ])
+
+          // Always populated by defaults.
+
+          // Between.
+          nextEvents = push(
+            nextEvents,
+            resolveAll(
+              context.parser.constructs.insideSpan.null,
+              events.slice(open + 1, index),
+              context
+            )
+          )
+
+          // Closing.
+          nextEvents = push(nextEvents, [
+            ['exit', text, context],
+            ['enter', closingSequence, context],
+            ['exit', closingSequence, context],
+            ['exit', group, context]
+          ])
+
+          // If there are more markers in the closing, add them after.
+          if (events[index][1].end.offset - events[index][1].start.offset) {
+            offset = 2
+            nextEvents = push(nextEvents, [
+              ['enter', events[index][1], context],
+              ['exit', events[index][1], context]
+            ])
+          } else {
+            offset = 0
+          }
+          splice(events, open - 1, index - open + 3, nextEvents)
+          index = open + nextEvents.length - offset - 2
+          break
+        }
+      }
+    }
+  }
+
+  // Remove remaining sequences.
+  index = -1
+  while (++index < events.length) {
+    if (events[index][1].type === 'attentionSequence') {
+      events[index][1].type = 'data'
+    }
+  }
+  return events
+}
+
+/**
+ * @this {TokenizeContext}
+ * @type {Tokenizer}
+ */
+function tokenizeAttention(effects, ok) {
+  const attentionMarkers = this.parser.constructs.attentionMarkers.null
+  const previous = this.previous
+  const before = classifyCharacter(previous)
+
+  /** @type {NonNullable<Code>} */
+  let marker
+  return start
+
+  /**
+   * Before a sequence.
+   *
+   * ```markdown
+   * > | **
+   *     ^
+   * ```
+   *
+   * @type {State}
+   */
+  function start(code) {
+    marker = code
+    effects.enter('attentionSequence')
+    return inside(code)
+  }
+
+  /**
+   * In a sequence.
+   *
+   * ```markdown
+   * > | **
+   *     ^^
+   * ```
+   *
+   * @type {State}
+   */
+  function inside(code) {
+    if (code === marker) {
+      effects.consume(code)
+      return inside
+    }
+    const token = effects.exit('attentionSequence')
+
+    // To do: next major: move this to resolver, just like `markdown-rs`.
+    const after = classifyCharacter(code)
+
+    // Always populated by defaults.
+
+    const open =
+      !after || (after === 2 && before) || attentionMarkers.includes(code)
+    const close =
+      !before || (before === 2 && after) || attentionMarkers.includes(previous)
+    token._open = Boolean(marker === 42 ? open : open && (before || !close))
+    token._close = Boolean(marker === 42 ? close : close && (after || !open))
+    return ok(code)
+  }
+}
+
+/**
+ * Move a point a bit.
+ *
+ * Note: `move` only works inside lines! It’s not possible to move past other
+ * chunks (replacement characters, tabs, or line endings).
+ *
+ * @param {Point} point
+ * @param {number} offset
+ * @returns {void}
+ */
+function movePoint(point, offset) {
+  point.column += offset
+  point.offset += offset
+  point._bufferIndex += offset
+}