content: // Copyright 2016 Google Inc. 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.
  
  import 'dart:collection';
  
  import 'package:collection/collection.dart';
  
  import 'callable.dart';
  import 'functions/color.dart' as color;
  import 'functions/list.dart' as list;
  import 'functions/map.dart' as map;
  import 'functions/math.dart' as math;
  import 'functions/meta.dart' as meta;
  import 'functions/selector.dart' as selector;
  import 'functions/string.dart' as string;
  
  /// Sass core functions that are globally available.
  ///
  /// This excludes a few functions that need access to the evaluation context;
  /// these are defined in `_EvaluateVisitor`.
  final List<BuiltInCallable> globalFunctions = UnmodifiableListView([
    ...color.global,
    ...list.global,
    ...map.global,
    ...math.global,
    ...selector.global,
    ...string.global,
    ...meta.global,
  
    // This is only invoked using `call()`. Hand-authored `if()`s are parsed as
    // [IfExpression]s.
    BuiltInCallable.function(
      "if",
      r"$condition, $if-true, $if-false",
      (arguments) => arguments[0].isTruthy ? arguments[1] : arguments[2],
    ),
  ]);
  
  /// Sass's core library modules.
  ///
  /// This doesn't include the `meta` module, because that needs additional
  /// functions that can only be defined in the evaluator itself.
  final coreModules = UnmodifiableListView([
    color.module,
    list.module,
    map.module,
    math.module,
    selector.module,
    string.module,
  ]);
  