lunr.TokenSet.fromFuzzyString = function()

in releases/2.7.6/dotnetdoc/styles/lunr.js [1227:1364]
107 lines of code
22 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
      } else {
        stack.push({
          node: noEditNode,
          editsRemaining: frame.editsRemaining,
          str: frame.str.slice(1)
        })
      }
    }

    // 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.editsRemaining > 0 && frame.str.length > 1) {
      var char = frame.str.charAt(1),
          deletionNode

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

      if (frame.str.length <= 2) {
        deletionNode.final = true
      } else {
        stack.push({
          node: deletionNode,
          editsRemaining: frame.editsRemaining - 1,
          str: frame.str.slice(2)
        })
      }
    }

    // deletion
    // just removing the last character from the str
    if (frame.editsRemaining > 0 && 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.editsRemaining > 0 && 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
      } else {
        stack.push({
          node: substitutionNode,
          editsRemaining: frame.editsRemaining - 1,
          str: frame.str.slice(1)
        })
      }
    }

    // insertion
    // can only do insertion if there are edits remaining
    if (frame.editsRemaining > 0) {
      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
      } else {
        stack.push({
          node: insertionNode,
          editsRemaining: frame.editsRemaining - 1,
          str: frame.str
        })
      }
    }

    // transposition
    // can only do a transposition if there are edits remaining
    // and there are enough characters to transpose
    if (frame.editsRemaining > 0 && 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
      } else {
        stack.push({
          node: transposeNode,
          editsRemaining: frame.editsRemaining - 1,
          str: charA + frame.str.slice(2)
        })
      }
    }
  }

  return root
}