content: // Copyright 2019 Google LLC
  //
  // Use of this source code is governed by an MIT-style
  // license that can be found in the LICENSE file or at
  // https://opensource.org/licenses/MIT.
  
  /// Mapping from existing built-in function name to the module it's now part of.
  const builtInFunctionModules = {
    "red": "color",
    "blue": "color",
    "green": "color",
    "mix": "color",
    "hue": "color",
    "saturation": "color",
    "lightness": "color",
    "adjust-hue": "color",
    "lighten": "color",
    "darken": "color",
    "saturate": "color",
    "desaturate": "color",
    "grayscale": "color",
    "complement": "color",
    "invert": "color",
    "alpha": "color",
    "opacity": "color",
    "opacify": "color",
    "fade-in": "color",
    "transparentize": "color",
    "fade-out": "color",
    "adjust-color": "color",
    "scale-color": "color",
    "change-color": "color",
    "ie-hex-str": "color",
    "map-get": "map",
    "map-merge": "map",
    "map-remove": "map",
    "map-keys": "map",
    "map-values": "map",
    "map-has-key": "map",
    "selector-nest": "selector",
    "selector-append": "selector",
    "selector-replace": "selector",
    "selector-unify": "selector",
    "is-superselector": "selector",
    "simple-selectors": "selector",
    "selector-parse": "selector",
    "selector-extend": "selector",
    "percentage": "math",
    "round": "math",
    "ceil": "math",
    "floor": "math",
    "abs": "math",
    "min": "math",
    "max": "math",
    "random": "math",
    "unit": "math",
    "unitless": "math",
    "comparable": "math",
    "length": "list",
    "nth": "list",
    "set-nth": "list",
    "join": "list",
    "append": "list",
    "zip": "list",
    "index": "list",
    "list-separator": "list",
    "is-bracketed": "list",
    "feature-exists": "meta",
    "variable-exists": "meta",
    "global-variable-exists": "meta",
    "function-exists": "meta",
    "mixin-exists": "meta",
    "inspect": "meta",
    "get-function": "meta",
    "type-of": "meta",
    "call": "meta",
    "content-exists": "meta",
    "keywords": "meta",
    "unquote": "string",
    "quote": "string",
    "str-length": "string",
    "str-insert": "string",
    "str-index": "string",
    "str-slice": "string",
    "to-upper-case": "string",
    "to-lower-case": "string",
    "unique-id": "string"
  };
  
  /// Mapping from old function name to new name, excluding namespace.
  const builtInFunctionNameChanges = {
    "adjust-color": "adjust",
    "scale-color": "scale",
    "change-color": "change",
    "map-get": "get",
    "map-merge": "merge",
    "map-remove": "remove",
    "map-keys": "keys",
    "map-values": "values",
    "map-has-key": "has-key",
    "selector-nest": "nest",
    "selector-append": "append",
    "selector-replace": "replace",
    "selector-unify": "unify",
    "selector-parse": "parse",
    "selector-extend": "extend",
    "unitless": "is-unitless",
    "comparable": "compatible",
    "list-separator": "separator",
    "str-length": "length",
    "str-insert": "insert",
    "str-index": "index",
    "str-slice": "slice"
  };
  
  /// Mapping from removed color function names to the parameter passed to
  /// `adjust-color` for the same effect.
  ///
  /// If the value from the removed function must be negated when passed to
  /// `adjust-color`, the parameter ends with a `-`.
  const removedColorFunctions = {
    "adjust-hue": r"$hue: ",
    "lighten": r"$lightness: ",
    "darken": r"$lightness: -",
    "saturate": r"$saturation: ",
    "desaturate": r"$saturation: -",
    "opacify": r"$alpha: ",
    "fade-in": r"$alpha: ",
    "transparentize": r"$alpha: -",
    "fade-out": r"$alpha: -"
  };
  