micromark-extension-directive/dev/lib/factory-attributes.js

micromark extension to support generic directives (`:cite[smith04]`)

/**
 * @import {Code, Effects, State, TokenType} from 'micromark-util-types'
 */

import {ok as assert} from 'devlop'
import {factorySpace} from 'micromark-factory-space'
import {factoryWhitespace} from 'micromark-factory-whitespace'
import {
  markdownLineEnding,
  markdownLineEndingOrSpace,
  markdownSpace,
  unicodePunctuation,
  unicodeWhitespace
} from 'micromark-util-character'
import {codes, types} from 'micromark-util-symbol'

/**
 * @param {Effects} effects
 * @param {State} ok
 * @param {State} nok
 * @param {TokenType} attributesType
 * @param {TokenType} attributesMarkerType
 * @param {TokenType} attributeType
 * @param {TokenType} attributeIdType
 * @param {TokenType} attributeClassType
 * @param {TokenType} attributeNameType
 * @param {TokenType} attributeInitializerType
 * @param {TokenType} attributeValueLiteralType
 * @param {TokenType} attributeValueType
 * @param {TokenType} attributeValueMarker
 * @param {TokenType} attributeValueData
 * @param {boolean | undefined} [disallowEol=false]
 */
export function factoryAttributes(
  effects,
  ok,
  nok,
  attributesType,
  attributesMarkerType,
  attributeType,
  attributeIdType,
  attributeClassType,
  attributeNameType,
  attributeInitializerType,
  attributeValueLiteralType,
  attributeValueType,
  attributeValueMarker,
  attributeValueData,
  disallowEol
) {
  /** @type {TokenType} */
  let type
  /** @type {Code | undefined} */
  let marker

  return start

  /** @type {State} */
  function start(code) {
    assert(code === codes.leftCurlyBrace, 'expected `{`')
    effects.enter(attributesType)
    effects.enter(attributesMarkerType)
    effects.consume(code)
    effects.exit(attributesMarkerType)
    return between
  }

  /** @type {State} */
  function between(code) {
    if (code === codes.numberSign) {
      type = attributeIdType
      return shortcutStart(code)
    }

    if (code === codes.dot) {
      type = attributeClassType
      return shortcutStart(code)
    }

    if (disallowEol && markdownSpace(code)) {
      return factorySpace(effects, between, types.whitespace)(code)
    }

    if (!disallowEol && markdownLineEndingOrSpace(code)) {
      return factoryWhitespace(effects, between)(code)
    }

    if (
      code === codes.eof ||
      markdownLineEnding(code) ||
      unicodeWhitespace(code) ||
      (unicodePunctuation(code) &&
        code !== codes.dash &&
        code !== codes.underscore)
    ) {
      return end(code)
    }

    effects.enter(attributeType)
    effects.enter(attributeNameType)
    effects.consume(code)
    return name
  }

  /** @type {State} */
  function shortcutStart(code) {
    // Assume it’s registered.
    const markerType = /** @type {TokenType} */ (type + 'Marker')
    effects.enter(attributeType)
    effects.enter(type)
    effects.enter(markerType)
    effects.consume(code)
    effects.exit(markerType)
    return shortcutStartAfter
  }

  /** @type {State} */
  function shortcutStartAfter(code) {
    if (
      code === codes.eof ||
      code === codes.quotationMark ||
      code === codes.numberSign ||
      code === codes.apostrophe ||
      code === codes.dot ||
      code === codes.lessThan ||
      code === codes.equalsTo ||
      code === codes.greaterThan ||
      code === codes.graveAccent ||
      code === codes.rightCurlyBrace ||
      markdownLineEndingOrSpace(code)
    ) {
      return nok(code)
    }

    // Assume it’s registered.
    const valueType = /** @type {TokenType} */ (type + 'Value')
    effects.enter(valueType)
    effects.consume(code)
    return shortcut
  }

  /** @type {State} */
  function shortcut(code) {
    if (
      code === codes.eof ||
      code === codes.quotationMark ||
      code === codes.apostrophe ||
      code === codes.lessThan ||
      code === codes.equalsTo ||
      code === codes.greaterThan ||
      code === codes.graveAccent
    ) {
      return nok(code)
    }

    if (
      code === codes.numberSign ||
      code === codes.dot ||
      code === codes.rightCurlyBrace ||
      markdownLineEndingOrSpace(code)
    ) {
      // Assume it’s registered.
      const valueType = /** @type {TokenType} */ (type + 'Value')
      effects.exit(valueType)
      effects.exit(type)
      effects.exit(attributeType)
      return between(code)
    }

    effects.consume(code)
    return shortcut
  }

  /** @type {State} */
  function name(code) {
    if (
      code === codes.eof ||
      markdownLineEnding(code) ||
      unicodeWhitespace(code) ||
      (unicodePunctuation(code) &&
        code !== codes.dash &&
        code !== codes.dot &&
        code !== codes.colon &&
        code !== codes.underscore)
    ) {
      effects.exit(attributeNameType)

      if (disallowEol && markdownSpace(code)) {
        return factorySpace(effects, nameAfter, types.whitespace)(code)
      }

      if (!disallowEol && markdownLineEndingOrSpace(code)) {
        return factoryWhitespace(effects, nameAfter)(code)
      }

      return nameAfter(code)
    }

    effects.consume(code)
    return name
  }

  /** @type {State} */
  function nameAfter(code) {
    if (code === codes.equalsTo) {
      effects.enter(attributeInitializerType)
      effects.consume(code)
      effects.exit(attributeInitializerType)
      return valueBefore
    }

    // Attribute w/o value.
    effects.exit(attributeType)
    return between(code)
  }

  /** @type {State} */
  function valueBefore(code) {
    if (
      code === codes.eof ||
      code === codes.lessThan ||
      code === codes.equalsTo ||
      code === codes.greaterThan ||
      code === codes.graveAccent ||
      code === codes.rightCurlyBrace ||
      (disallowEol && markdownLineEnding(code))
    ) {
      return nok(code)
    }

    if (code === codes.quotationMark || code === codes.apostrophe) {
      effects.enter(attributeValueLiteralType)
      effects.enter(attributeValueMarker)
      effects.consume(code)
      effects.exit(attributeValueMarker)
      marker = code
      return valueQuotedStart
    }

    if (disallowEol && markdownSpace(code)) {
      return factorySpace(effects, valueBefore, types.whitespace)(code)
    }

    if (!disallowEol && markdownLineEndingOrSpace(code)) {
      return factoryWhitespace(effects, valueBefore)(code)
    }

    effects.enter(attributeValueType)
    effects.enter(attributeValueData)
    effects.consume(code)
    marker = undefined
    return valueUnquoted
  }

  /** @type {State} */
  function valueUnquoted(code) {
    if (
      code === codes.eof ||
      code === codes.quotationMark ||
      code === codes.apostrophe ||
      code === codes.lessThan ||
      code === codes.equalsTo ||
      code === codes.greaterThan ||
      code === codes.graveAccent
    ) {
      return nok(code)
    }

    if (code === codes.rightCurlyBrace || markdownLineEndingOrSpace(code)) {
      effects.exit(attributeValueData)
      effects.exit(attributeValueType)
      effects.exit(attributeType)
      return between(code)
    }

    effects.consume(code)
    return valueUnquoted
  }

  /** @type {State} */
  function valueQuotedStart(code) {
    if (code === marker) {
      effects.enter(attributeValueMarker)
      effects.consume(code)
      effects.exit(attributeValueMarker)
      effects.exit(attributeValueLiteralType)
      effects.exit(attributeType)
      return valueQuotedAfter
    }

    effects.enter(attributeValueType)
    return valueQuotedBetween(code)
  }

  /** @type {State} */
  function valueQuotedBetween(code) {
    if (code === marker) {
      effects.exit(attributeValueType)
      return valueQuotedStart(code)
    }

    if (code === codes.eof) {
      return nok(code)
    }

    // Note: blank lines can’t exist in content.
    if (markdownLineEnding(code)) {
      return disallowEol
        ? nok(code)
        : factoryWhitespace(effects, valueQuotedBetween)(code)
    }

    effects.enter(attributeValueData)
    effects.consume(code)
    return valueQuoted
  }

  /** @type {State} */
  function valueQuoted(code) {
    if (code === marker || code === codes.eof || markdownLineEnding(code)) {
      effects.exit(attributeValueData)
      return valueQuotedBetween(code)
    }

    effects.consume(code)
    return valueQuoted
  }

  /** @type {State} */
  function valueQuotedAfter(code) {
    return code === codes.rightCurlyBrace || markdownLineEndingOrSpace(code)
      ? between(code)
      : end(code)
  }

  /** @type {State} */
  function end(code) {
    if (code === codes.rightCurlyBrace) {
      effects.enter(attributesMarkerType)
      effects.consume(code)
      effects.exit(attributesMarkerType)
      effects.exit(attributesType)
      return ok
    }

    return nok(code)
  }
}