devdocs/assets/javascripts/app/searcher.js

/*
 * decaffeinate suggestions:
 * DS002: Fix invalid constructor
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS104: Avoid inline assignments
 * DS202: Simplify dynamic range loops
 * DS206: Consider reworking classes to avoid initClass
 * DS207: Consider shorter variations of null checks
 * DS209: Avoid top-level return
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/main/docs/suggestions.md
 */
//
// Match functions
//

let fuzzyRegexp, i, index, lastIndex, match, matcher, matchIndex, matchLength, queryLength, score, separators, value, valueLength;
const SEPARATOR = '.';

let query =
(queryLength =
(value =
(valueLength =
(matcher =     // current match function
(fuzzyRegexp = // query fuzzy regexp
(index =       // position of the query in the string being matched
(lastIndex =   // last position of the query in the string being matched
(match =       // regexp match data
(matchIndex =
(matchLength =
(score =       // score for the current match
(separators =  // counter
(i = null)))))))))))));      // cursor

function exactMatch() {
index = value.indexOf(query);
if (!(index >= 0)) { return; }

lastIndex = value.lastIndexOf(query);

if (index !== lastIndex) {
  return Math.max(scoreExactMatch(), ((index = lastIndex) && scoreExactMatch()) || 0);
} else {
  return scoreExactMatch();
}
}

function scoreExactMatch() {
// Remove one point for each unmatched character.
score = 100 - (valueLength - queryLength);

if (index > 0) {
  // If the character preceding the query is a dot, assign the same score
  // as if the query was found at the beginning of the string, minus one.
  if (value.charAt(index - 1) === SEPARATOR) {
    score += index - 1;
  // Don't match a single-character query unless it's found at the beginning
  // of the string or is preceded by a dot.
  } else if (queryLength === 1) {
    return;
  // (1) Remove one point for each unmatched character up to the nearest
  //     preceding dot or the beginning of the string.
  // (2) Remove one point for each unmatched character following the query.
  } else {
    i = index - 2;
    while ((i >= 0) && (value.charAt(i) !== SEPARATOR)) { i--; }
    score -= (index - i) +                       // (1)
             (valueLength - queryLength - index); // (2)
  }

  // Remove one point for each dot preceding the query, except for the one
  // immediately before the query.
  separators = 0;
  i = index - 2;
  while (i >= 0) {
    if (value.charAt(i) === SEPARATOR) { separators++; }
    i--;
  }
  score -= separators;
}

// Remove five points for each dot following the query.
separators = 0;
i = valueLength - queryLength - index - 1;
while (i >= 0) {
  if (value.charAt(index + queryLength + i) === SEPARATOR) { separators++; }
  i--;
}
score -= separators * 5;

return Math.max(1, score);
}

function fuzzyMatch() {
if ((valueLength <= queryLength) || (value.indexOf(query) >= 0)) { return; }
if (!(match = fuzzyRegexp.exec(value))) { return; }
matchIndex = match.index;
matchLength = match[0].length;
score = scoreFuzzyMatch();
if (match = fuzzyRegexp.exec(value.slice(i = value.lastIndexOf(SEPARATOR) + 1))) {
  matchIndex = i + match.index;
  matchLength = match[0].length;
  return Math.max(score, scoreFuzzyMatch());
} else {
  return score;
}
}

function scoreFuzzyMatch() {
// When the match is at the beginning of the string or preceded by a dot.
if ((matchIndex === 0) || (value.charAt(matchIndex - 1) === SEPARATOR)) {
  return Math.max(66, 100 - matchLength);
// When the match is at the end of the string.
} else if ((matchIndex + matchLength) === valueLength) {
  return Math.max(33, 67 - matchLength);
// When the match is in the middle of the string.
} else {
  return Math.max(1, 34 - matchLength);
}
}

//
// Searchers
//

(function() {
  let CHUNK_SIZE = undefined;
  let DEFAULTS = undefined;
  let SEPARATORS_REGEXP = undefined;
  let EOS_SEPARATORS_REGEXP = undefined;
  let INFO_PARANTHESES_REGEXP = undefined;
  let EMPTY_PARANTHESES_REGEXP = undefined;
  let EVENT_REGEXP = undefined;
  let DOT_REGEXP = undefined;
  let WHITESPACE_REGEXP = undefined;
  let EMPTY_STRING = undefined;
  let ELLIPSIS = undefined;
  let STRING = undefined;
  const Cls = (app.Searcher = class Searcher {
    static initClass() {
      $.extend(this.prototype, Events);
  
      CHUNK_SIZE = 20000;
  
      DEFAULTS = {
        max_results: app.config.max_results,
        fuzzy_min_length: 3
      };
  
      SEPARATORS_REGEXP = /#|::|:-|->|\$(?=\w)|\-(?=\w)|\:(?=\w)|\ [\/\-&]\ |:\ |\ /g;
      EOS_SEPARATORS_REGEXP = /(\w)[\-:]$/;
      INFO_PARANTHESES_REGEXP = /\ \(\w+?\)$/;
      EMPTY_PARANTHESES_REGEXP = /\(\)/;
      EVENT_REGEXP = /\ event$/;
      DOT_REGEXP = /\.+/g;
      WHITESPACE_REGEXP = /\s/g;
  
      EMPTY_STRING = '';
      ELLIPSIS = '...';
      STRING = 'string';
    }

    static normalizeString(string) {
      return string
        .toLowerCase()
        .replace(ELLIPSIS, EMPTY_STRING)
        .replace(EVENT_REGEXP, EMPTY_STRING)
        .replace(INFO_PARANTHESES_REGEXP, EMPTY_STRING)
        .replace(SEPARATORS_REGEXP, SEPARATOR)
        .replace(DOT_REGEXP, SEPARATOR)
        .replace(EMPTY_PARANTHESES_REGEXP, EMPTY_STRING)
        .replace(WHITESPACE_REGEXP, EMPTY_STRING);
    }

    static normalizeQuery(string) {
      string = this.normalizeString(string);
      return string.replace(EOS_SEPARATORS_REGEXP, '$1.');
    }

    constructor(options) {
      this.match = this.match.bind(this);
      this.matchChunks = this.matchChunks.bind(this);
      if (options == null) { options = {}; }
      this.options = $.extend({}, DEFAULTS, options);
    }

    find(data, attr, q) {
      this.kill();

      this.data = data;
      this.attr = attr;
      this.query = q;
      this.setup();

      if (this.isValid()) { this.match(); } else { this.end(); }
    }

    setup() {
      query = (this.query = this.constructor.normalizeQuery(this.query));
      queryLength = query.length;
      this.dataLength = this.data.length;
      this.matchers = [exactMatch];
      this.totalResults = 0;
      this.setupFuzzy();
    }

    setupFuzzy() {
      if (queryLength >= this.options.fuzzy_min_length) {
        fuzzyRegexp = this.queryToFuzzyRegexp(query);
        this.matchers.push(fuzzyMatch);
      } else {
        fuzzyRegexp = null;
      }
    }

    isValid() {
      return (queryLength > 0) && (query !== SEPARATOR);
    }

    end() {
      if (!this.totalResults) { this.triggerResults([]); }
      this.trigger('end');
      this.free();
    }

    kill() {
      if (this.timeout) {
        clearTimeout(this.timeout);
        this.free();
      }
    }

    free() {
      this.data = (this.attr = (this.dataLength = (this.matchers = (this.matcher = (this.query =
      (this.totalResults = (this.scoreMap = (this.cursor = (this.timeout = null)))))))));
    }

    match() {
      if (!this.foundEnough() && (this.matcher = this.matchers.shift())) {
        this.setupMatcher();
        this.matchChunks();
      } else {
        this.end();
      }
    }

    setupMatcher() {
      this.cursor = 0;
      this.scoreMap = new Array(101);
    }

    matchChunks() {
      this.matchChunk();

      if ((this.cursor === this.dataLength) || this.scoredEnough()) {
        this.delay(this.match);
        this.sendResults();
      } else {
        this.delay(this.matchChunks);
      }
    }

    matchChunk() {
      ({
        matcher
      } = this);
      for (let j = 0, end = this.chunkSize(), asc = 0 <= end; asc ? j < end : j > end; asc ? j++ : j--) {
        value = this.data[this.cursor][this.attr];
        if (value.split) { // string
          valueLength = value.length;
          if (score = matcher()) { this.addResult(this.data[this.cursor], score); }
        } else { // array
          score = 0;
          for (value of Array.from(this.data[this.cursor][this.attr])) {
            valueLength = value.length;
            score = Math.max(score, matcher() || 0);
          }
          if (score > 0) { this.addResult(this.data[this.cursor], score); }
        }
        this.cursor++;
      }
    }

    chunkSize() {
      if ((this.cursor + CHUNK_SIZE) > this.dataLength) {
        return this.dataLength % CHUNK_SIZE;
      } else {
        return CHUNK_SIZE;
      }
    }

    scoredEnough() {
       return (this.scoreMap[100] != null ? this.scoreMap[100].length : undefined) >= this.options.max_results;
     }

    foundEnough() {
      return this.totalResults >= this.options.max_results;
    }

    addResult(object, score) {
      let name;
      (this.scoreMap[name = Math.round(score)] || (this.scoreMap[name] = [])).push(object);
      this.totalResults++;
    }

    getResults() {
      const results = [];
      for (let j = this.scoreMap.length - 1; j >= 0; j--) {
        var objects = this.scoreMap[j];
        if (objects) {
          results.push.apply(results, objects);
        }
      }
      return results.slice(0, this.options.max_results);
    }

    sendResults() {
      const results = this.getResults();
      if (results.length) { this.triggerResults(results); }
    }

    triggerResults(results) {
      this.trigger('results', results);
    }

    delay(fn) {
      return this.timeout = setTimeout(fn, 1);
    }

    queryToFuzzyRegexp(string) {
      const chars = string.split('');
      for (i = 0; i < chars.length; i++) { var char = chars[i]; chars[i] = $.escapeRegexp(char); }
      return new RegExp(chars.join('.*?'));
    }
  });
  Cls.initClass();
  return Cls; // abc -> /a.*?b.*?c.*?/
})();

app.SynchronousSearcher = class SynchronousSearcher extends app.Searcher {
  constructor(...args) {
    this.match = this.match.bind(this);
    super(...args);
  }

  match() {
    if (this.matcher) {
      if (!this.allResults) { this.allResults = []; }
      this.allResults.push.apply(this.allResults, this.getResults());
    }
    return super.match(...arguments);
  }

  free() {
    this.allResults = null;
    return super.free(...arguments);
  }

  end() {
    this.sendResults(true);
    return super.end(...arguments);
  }

  sendResults(end) {
    if (end && (this.allResults != null ? this.allResults.length : undefined)) {
      return this.triggerResults(this.allResults);
    }
  }

  delay(fn) {
    return fn();
  }
};