lunr.TokenSet.fromFuzzyString = function()

in content/references/java-chassis/en_US/search/lunr.js [1437:1561]
92 lines of code
16 McCabe index (conditional complexity)

lunr.TokenSet.fromFuzzyString = function (str, editDistance) {
  var root = new lunr.TokenSet

  var stack = [{
    node: root,
    editsRemaining: editDistance,
    str: str
  }]

  while (stack.length) {
    var frame = stack.pop()

    // no edit
    if (frame.str.length > 0) {
      var char = frame.str.charAt(0),
          noEditNode

      if (char in frame.node.edges) {
        noEditNode = frame.node.edges[char]
      } else {
        noEditNode = new lunr.TokenSet
        frame.node.edges[char] = noEditNode
      }

      if (frame.str.length == 1) {
        noEditNode.final = true
      }

      stack.push({
        node: noEditNode,
        editsRemaining: frame.editsRemaining,
        str: frame.str.slice(1)
      })
    }

    if (frame.editsRemaining == 0) {
      continue
    }

    // insertion
    if ("*" in frame.node.edges) {
      var insertionNode = frame.node.edges["*"]
    } else {
      var insertionNode = new lunr.TokenSet
      frame.node.edges["*"] = insertionNode
    }

    if (frame.str.length == 0) {
      insertionNode.final = true
    }

    stack.push({
      node: insertionNode,
      editsRemaining: frame.editsRemaining - 1,
      str: frame.str
    })

    // deletion
    // can only do a deletion if we have enough edits remaining
    // and if there are characters left to delete in the string
    if (frame.str.length > 1) {
      stack.push({
        node: frame.node,
        editsRemaining: frame.editsRemaining - 1,
        str: frame.str.slice(1)
      })
    }

    // deletion
    // just removing the last character from the str
    if (frame.str.length == 1) {
      frame.node.final = true
    }

    // substitution
    // can only do a substitution if we have enough edits remaining
    // and if there are characters left to substitute
    if (frame.str.length >= 1) {
      if ("*" in frame.node.edges) {
        var substitutionNode = frame.node.edges["*"]
      } else {
        var substitutionNode = new lunr.TokenSet
        frame.node.edges["*"] = substitutionNode
      }

      if (frame.str.length == 1) {
        substitutionNode.final = true
      }

      stack.push({
        node: substitutionNode,
        editsRemaining: frame.editsRemaining - 1,
        str: frame.str.slice(1)
      })
    }

    // transposition
    // can only do a transposition if there are edits remaining
    // and there are enough characters to transpose
    if (frame.str.length > 1) {
      var charA = frame.str.charAt(0),
          charB = frame.str.charAt(1),
          transposeNode

      if (charB in frame.node.edges) {
        transposeNode = frame.node.edges[charB]
      } else {
        transposeNode = new lunr.TokenSet
        frame.node.edges[charB] = transposeNode
      }

      if (frame.str.length == 1) {
        transposeNode.final = true
      }

      stack.push({
        node: transposeNode,
        editsRemaining: frame.editsRemaining - 1,
        str: charA + frame.str.slice(2)
      })
    }
  }

  return root
}