nunjucks/src/compiler.js

A powerful templating engine with inheritance, asynchronous control, and more (jinja2 inspired)

'use strict';

function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; _setPrototypeOf(subClass, superClass); }
function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf ? Object.setPrototypeOf.bind() : function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
var parser = require('./parser');
var transformer = require('./transformer');
var nodes = require('./nodes');
var _require = require('./lib'),
  TemplateError = _require.TemplateError;
var _require2 = require('./runtime'),
  Frame = _require2.Frame;
var _require3 = require('./object'),
  Obj = _require3.Obj;

// These are all the same for now, but shouldn't be passed straight
// through
var compareOps = {
  '==': '==',
  '===': '===',
  '!=': '!=',
  '!==': '!==',
  '<': '<',
  '>': '>',
  '<=': '<=',
  '>=': '>='
};
var Compiler = /*#__PURE__*/function (_Obj) {
  _inheritsLoose(Compiler, _Obj);
  function Compiler() {
    return _Obj.apply(this, arguments) || this;
  }
  var _proto = Compiler.prototype;
  _proto.init = function init(templateName, throwOnUndefined) {
    this.templateName = templateName;
    this.codebuf = [];
    this.lastId = 0;
    this.buffer = null;
    this.bufferStack = [];
    this._scopeClosers = '';
    this.inBlock = false;
    this.throwOnUndefined = throwOnUndefined;
  };
  _proto.fail = function fail(msg, lineno, colno) {
    if (lineno !== undefined) {
      lineno += 1;
    }
    if (colno !== undefined) {
      colno += 1;
    }
    throw new TemplateError(msg, lineno, colno);
  };
  _proto._pushBuffer = function _pushBuffer() {
    var id = this._tmpid();
    this.bufferStack.push(this.buffer);
    this.buffer = id;
    this._emit("var " + this.buffer + " = \"\";");
    return id;
  };
  _proto._popBuffer = function _popBuffer() {
    this.buffer = this.bufferStack.pop();
  };
  _proto._emit = function _emit(code) {
    this.codebuf.push(code);
  };
  _proto._emitLine = function _emitLine(code) {
    this._emit(code + '\n');
  };
  _proto._emitLines = function _emitLines() {
    var _this = this;
    for (var _len = arguments.length, lines = new Array(_len), _key = 0; _key < _len; _key++) {
      lines[_key] = arguments[_key];
    }
    lines.forEach(function (line) {
      return _this._emitLine(line);
    });
  };
  _proto._emitFuncBegin = function _emitFuncBegin(node, name) {
    this.buffer = 'output';
    this._scopeClosers = '';
    this._emitLine("function " + name + "(env, context, frame, runtime, cb) {");
    this._emitLine("var lineno = " + node.lineno + ";");
    this._emitLine("var colno = " + node.colno + ";");
    this._emitLine("var " + this.buffer + " = \"\";");
    this._emitLine('try {');
  };
  _proto._emitFuncEnd = function _emitFuncEnd(noReturn) {
    if (!noReturn) {
      this._emitLine('cb(null, ' + this.buffer + ');');
    }
    this._closeScopeLevels();
    this._emitLine('} catch (e) {');
    this._emitLine('  cb(runtime.handleError(e, lineno, colno));');
    this._emitLine('}');
    this._emitLine('}');
    this.buffer = null;
  };
  _proto._addScopeLevel = function _addScopeLevel() {
    this._scopeClosers += '})';
  };
  _proto._closeScopeLevels = function _closeScopeLevels() {
    this._emitLine(this._scopeClosers + ';');
    this._scopeClosers = '';
  };
  _proto._withScopedSyntax = function _withScopedSyntax(func) {
    var _scopeClosers = this._scopeClosers;
    this._scopeClosers = '';
    func.call(this);
    this._closeScopeLevels();
    this._scopeClosers = _scopeClosers;
  };
  _proto._makeCallback = function _makeCallback(res) {
    var err = this._tmpid();
    return 'function(' + err + (res ? ',' + res : '') + ') {\n' + 'if(' + err + ') { cb(' + err + '); return; }';
  };
  _proto._tmpid = function _tmpid() {
    this.lastId++;
    return 't_' + this.lastId;
  };
  _proto._templateName = function _templateName() {
    return this.templateName == null ? 'undefined' : JSON.stringify(this.templateName);
  };
  _proto._compileChildren = function _compileChildren(node, frame) {
    var _this2 = this;
    node.children.forEach(function (child) {
      _this2.compile(child, frame);
    });
  };
  _proto._compileAggregate = function _compileAggregate(node, frame, startChar, endChar) {
    var _this3 = this;
    if (startChar) {
      this._emit(startChar);
    }
    node.children.forEach(function (child, i) {
      if (i > 0) {
        _this3._emit(',');
      }
      _this3.compile(child, frame);
    });
    if (endChar) {
      this._emit(endChar);
    }
  };
  _proto._compileExpression = function _compileExpression(node, frame) {
    // TODO: I'm not really sure if this type check is worth it or
    // not.
    this.assertType(node, nodes.Literal, nodes.Symbol, nodes.Group, nodes.Array, nodes.Dict, nodes.FunCall, nodes.Caller, nodes.Filter, nodes.LookupVal, nodes.Compare, nodes.InlineIf, nodes.In, nodes.Is, nodes.And, nodes.Or, nodes.Not, nodes.Add, nodes.Concat, nodes.Sub, nodes.Mul, nodes.Div, nodes.FloorDiv, nodes.Mod, nodes.Pow, nodes.Neg, nodes.Pos, nodes.Compare, nodes.NodeList);
    this.compile(node, frame);
  };
  _proto.assertType = function assertType(node) {
    for (var _len2 = arguments.length, types = new Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
      types[_key2 - 1] = arguments[_key2];
    }
    if (!types.some(function (t) {
      return node instanceof t;
    })) {
      this.fail("assertType: invalid type: " + node.typename, node.lineno, node.colno);
    }
  };
  _proto.compileCallExtension = function compileCallExtension(node, frame, async) {
    var _this4 = this;
    var args = node.args;
    var contentArgs = node.contentArgs;
    var autoescape = typeof node.autoescape === 'boolean' ? node.autoescape : true;
    if (!async) {
      this._emit(this.buffer + " += runtime.suppressValue(");
    }
    this._emit("env.getExtension(\"" + node.extName + "\")[\"" + node.prop + "\"](");
    this._emit('context');
    if (args || contentArgs) {
      this._emit(',');
    }
    if (args) {
      if (!(args instanceof nodes.NodeList)) {
        this.fail('compileCallExtension: arguments must be a NodeList, ' + 'use `parser.parseSignature`');
      }
      args.children.forEach(function (arg, i) {
        // Tag arguments are passed normally to the call. Note
        // that keyword arguments are turned into a single js
        // object as the last argument, if they exist.
        _this4._compileExpression(arg, frame);
        if (i !== args.children.length - 1 || contentArgs.length) {
          _this4._emit(',');
        }
      });
    }
    if (contentArgs.length) {
      contentArgs.forEach(function (arg, i) {
        if (i > 0) {
          _this4._emit(',');
        }
        if (arg) {
          _this4._emitLine('function(cb) {');
          _this4._emitLine('if(!cb) { cb = function(err) { if(err) { throw err; }}}');
          var id = _this4._pushBuffer();
          _this4._withScopedSyntax(function () {
            _this4.compile(arg, frame);
            _this4._emitLine("cb(null, " + id + ");");
          });
          _this4._popBuffer();
          _this4._emitLine("return " + id + ";");
          _this4._emitLine('}');
        } else {
          _this4._emit('null');
        }
      });
    }
    if (async) {
      var res = this._tmpid();
      this._emitLine(', ' + this._makeCallback(res));
      this._emitLine(this.buffer + " += runtime.suppressValue(" + res + ", " + autoescape + " && env.opts.autoescape);");
      this._addScopeLevel();
    } else {
      this._emit(')');
      this._emit(", " + autoescape + " && env.opts.autoescape);\n");
    }
  };
  _proto.compileCallExtensionAsync = function compileCallExtensionAsync(node, frame) {
    this.compileCallExtension(node, frame, true);
  };
  _proto.compileNodeList = function compileNodeList(node, frame) {
    this._compileChildren(node, frame);
  };
  _proto.compileLiteral = function compileLiteral(node) {
    if (typeof node.value === 'string') {
      var val = node.value.replace(/\\/g, '\\\\');
      val = val.replace(/"/g, '\\"');
      val = val.replace(/\n/g, '\\n');
      val = val.replace(/\r/g, '\\r');
      val = val.replace(/\t/g, '\\t');
      val = val.replace(/\u2028/g, "\\u2028");
      this._emit("\"" + val + "\"");
    } else if (node.value === null) {
      this._emit('null');
    } else {
      this._emit(node.value.toString());
    }
  };
  _proto.compileSymbol = function compileSymbol(node, frame) {
    var name = node.value;
    var v = frame.lookup(name);
    if (v) {
      this._emit(v);
    } else {
      this._emit('runtime.contextOrFrameLookup(' + 'context, frame, "' + name + '")');
    }
  };
  _proto.compileGroup = function compileGroup(node, frame) {
    this._compileAggregate(node, frame, '(', ')');
  };
  _proto.compileArray = function compileArray(node, frame) {
    this._compileAggregate(node, frame, '[', ']');
  };
  _proto.compileDict = function compileDict(node, frame) {
    this._compileAggregate(node, frame, '{', '}');
  };
  _proto.compilePair = function compilePair(node, frame) {
    var key = node.key;
    var val = node.value;
    if (key instanceof nodes.Symbol) {
      key = new nodes.Literal(key.lineno, key.colno, key.value);
    } else if (!(key instanceof nodes.Literal && typeof key.value === 'string')) {
      this.fail('compilePair: Dict keys must be strings or names', key.lineno, key.colno);
    }
    this.compile(key, frame);
    this._emit(': ');
    this._compileExpression(val, frame);
  };
  _proto.compileInlineIf = function compileInlineIf(node, frame) {
    this._emit('(');
    this.compile(node.cond, frame);
    this._emit('?');
    this.compile(node.body, frame);
    this._emit(':');
    if (node.else_ !== null) {
      this.compile(node.else_, frame);
    } else {
      this._emit('""');
    }
    this._emit(')');
  };
  _proto.compileIn = function compileIn(node, frame) {
    this._emit('runtime.inOperator(');
    this.compile(node.left, frame);
    this._emit(',');
    this.compile(node.right, frame);
    this._emit(')');
  };
  _proto.compileIs = function compileIs(node, frame) {
    // first, we need to try to get the name of the test function, if it's a
    // callable (i.e., has args) and not a symbol.
    var right = node.right.name ? node.right.name.value
    // otherwise go with the symbol value
    : node.right.value;
    this._emit('env.getTest("' + right + '").call(context, ');
    this.compile(node.left, frame);
    // compile the arguments for the callable if they exist
    if (node.right.args) {
      this._emit(',');
      this.compile(node.right.args, frame);
    }
    this._emit(') === true');
  };
  _proto._binOpEmitter = function _binOpEmitter(node, frame, str) {
    this.compile(node.left, frame);
    this._emit(str);
    this.compile(node.right, frame);
  }

  // ensure concatenation instead of addition
  // by adding empty string in between
  ;
  _proto.compileOr = function compileOr(node, frame) {
    return this._binOpEmitter(node, frame, ' || ');
  };
  _proto.compileAnd = function compileAnd(node, frame) {
    return this._binOpEmitter(node, frame, ' && ');
  };
  _proto.compileAdd = function compileAdd(node, frame) {
    return this._binOpEmitter(node, frame, ' + ');
  };
  _proto.compileConcat = function compileConcat(node, frame) {
    return this._binOpEmitter(node, frame, ' + "" + ');
  };
  _proto.compileSub = function compileSub(node, frame) {
    return this._binOpEmitter(node, frame, ' - ');
  };
  _proto.compileMul = function compileMul(node, frame) {
    return this._binOpEmitter(node, frame, ' * ');
  };
  _proto.compileDiv = function compileDiv(node, frame) {
    return this._binOpEmitter(node, frame, ' / ');
  };
  _proto.compileMod = function compileMod(node, frame) {
    return this._binOpEmitter(node, frame, ' % ');
  };
  _proto.compileNot = function compileNot(node, frame) {
    this._emit('!');
    this.compile(node.target, frame);
  };
  _proto.compileFloorDiv = function compileFloorDiv(node, frame) {
    this._emit('Math.floor(');
    this.compile(node.left, frame);
    this._emit(' / ');
    this.compile(node.right, frame);
    this._emit(')');
  };
  _proto.compilePow = function compilePow(node, frame) {
    this._emit('Math.pow(');
    this.compile(node.left, frame);
    this._emit(', ');
    this.compile(node.right, frame);
    this._emit(')');
  };
  _proto.compileNeg = function compileNeg(node, frame) {
    this._emit('-');
    this.compile(node.target, frame);
  };
  _proto.compilePos = function compilePos(node, frame) {
    this._emit('+');
    this.compile(node.target, frame);
  };
  _proto.compileCompare = function compileCompare(node, frame) {
    var _this5 = this;
    this.compile(node.expr, frame);
    node.ops.forEach(function (op) {
      _this5._emit(" " + compareOps[op.type] + " ");
      _this5.compile(op.expr, frame);
    });
  };
  _proto.compileLookupVal = function compileLookupVal(node, frame) {
    this._emit('runtime.memberLookup((');
    this._compileExpression(node.target, frame);
    this._emit('),');
    this._compileExpression(node.val, frame);
    this._emit(')');
  };
  _proto._getNodeName = function _getNodeName(node) {
    switch (node.typename) {
      case 'Symbol':
        return node.value;
      case 'FunCall':
        return 'the return value of (' + this._getNodeName(node.name) + ')';
      case 'LookupVal':
        return this._getNodeName(node.target) + '["' + this._getNodeName(node.val) + '"]';
      case 'Literal':
        return node.value.toString();
      default:
        return '--expression--';
    }
  };
  _proto.compileFunCall = function compileFunCall(node, frame) {
    // Keep track of line/col info at runtime by settings
    // variables within an expression. An expression in javascript
    // like (x, y, z) returns the last value, and x and y can be
    // anything
    this._emit('(lineno = ' + node.lineno + ', colno = ' + node.colno + ', ');
    this._emit('runtime.callWrap(');
    // Compile it as normal.
    this._compileExpression(node.name, frame);

    // Output the name of what we're calling so we can get friendly errors
    // if the lookup fails.
    this._emit(', "' + this._getNodeName(node.name).replace(/"/g, '\\"') + '", context, ');
    this._compileAggregate(node.args, frame, '[', '])');
    this._emit(')');
  };
  _proto.compileFilter = function compileFilter(node, frame) {
    var name = node.name;
    this.assertType(name, nodes.Symbol);
    this._emit('env.getFilter("' + name.value + '").call(context, ');
    this._compileAggregate(node.args, frame);
    this._emit(')');
  };
  _proto.compileFilterAsync = function compileFilterAsync(node, frame) {
    var name = node.name;
    var symbol = node.symbol.value;
    this.assertType(name, nodes.Symbol);
    frame.set(symbol, symbol);
    this._emit('env.getFilter("' + name.value + '").call(context, ');
    this._compileAggregate(node.args, frame);
    this._emitLine(', ' + this._makeCallback(symbol));
    this._addScopeLevel();
  };
  _proto.compileKeywordArgs = function compileKeywordArgs(node, frame) {
    this._emit('runtime.makeKeywordArgs(');
    this.compileDict(node, frame);
    this._emit(')');
  };
  _proto.compileSet = function compileSet(node, frame) {
    var _this6 = this;
    var ids = [];

    // Lookup the variable names for each identifier and create
    // new ones if necessary
    node.targets.forEach(function (target) {
      var name = target.value;
      var id = frame.lookup(name);
      if (id === null || id === undefined) {
        id = _this6._tmpid();

        // Note: This relies on js allowing scope across
        // blocks, in case this is created inside an `if`
        _this6._emitLine('var ' + id + ';');
      }
      ids.push(id);
    });
    if (node.value) {
      this._emit(ids.join(' = ') + ' = ');
      this._compileExpression(node.value, frame);
      this._emitLine(';');
    } else {
      this._emit(ids.join(' = ') + ' = ');
      this.compile(node.body, frame);
      this._emitLine(';');
    }
    node.targets.forEach(function (target, i) {
      var id = ids[i];
      var name = target.value;

      // We are running this for every var, but it's very
      // uncommon to assign to multiple vars anyway
      _this6._emitLine("frame.set(\"" + name + "\", " + id + ", true);");
      _this6._emitLine('if(frame.topLevel) {');
      _this6._emitLine("context.setVariable(\"" + name + "\", " + id + ");");
      _this6._emitLine('}');
      if (name.charAt(0) !== '_') {
        _this6._emitLine('if(frame.topLevel) {');
        _this6._emitLine("context.addExport(\"" + name + "\", " + id + ");");
        _this6._emitLine('}');
      }
    });
  };
  _proto.compileSwitch = function compileSwitch(node, frame) {
    var _this7 = this;
    this._emit('switch (');
    this.compile(node.expr, frame);
    this._emit(') {');
    node.cases.forEach(function (c, i) {
      _this7._emit('case ');
      _this7.compile(c.cond, frame);
      _this7._emit(': ');
      _this7.compile(c.body, frame);
      // preserve fall-throughs
      if (c.body.children.length) {
        _this7._emitLine('break;');
      }
    });
    if (node.default) {
      this._emit('default:');
      this.compile(node.default, frame);
    }
    this._emit('}');
  };
  _proto.compileIf = function compileIf(node, frame, async) {
    var _this8 = this;
    this._emit('if(');
    this._compileExpression(node.cond, frame);
    this._emitLine(') {');
    this._withScopedSyntax(function () {
      _this8.compile(node.body, frame);
      if (async) {
        _this8._emit('cb()');
      }
    });
    if (node.else_) {
      this._emitLine('}\nelse {');
      this._withScopedSyntax(function () {
        _this8.compile(node.else_, frame);
        if (async) {
          _this8._emit('cb()');
        }
      });
    } else if (async) {
      this._emitLine('}\nelse {');
      this._emit('cb()');
    }
    this._emitLine('}');
  };
  _proto.compileIfAsync = function compileIfAsync(node, frame) {
    this._emit('(function(cb) {');
    this.compileIf(node, frame, true);
    this._emit('})(' + this._makeCallback());
    this._addScopeLevel();
  };
  _proto._emitLoopBindings = function _emitLoopBindings(node, arr, i, len) {
    var _this9 = this;
    var bindings = [{
      name: 'index',
      val: i + " + 1"
    }, {
      name: 'index0',
      val: i
    }, {
      name: 'revindex',
      val: len + " - " + i
    }, {
      name: 'revindex0',
      val: len + " - " + i + " - 1"
    }, {
      name: 'first',
      val: i + " === 0"
    }, {
      name: 'last',
      val: i + " === " + len + " - 1"
    }, {
      name: 'length',
      val: len
    }];
    bindings.forEach(function (b) {
      _this9._emitLine("frame.set(\"loop." + b.name + "\", " + b.val + ");");
    });
  };
  _proto.compileFor = function compileFor(node, frame) {
    var _this10 = this;
    // Some of this code is ugly, but it keeps the generated code
    // as fast as possible. ForAsync also shares some of this, but
    // not much.

    var i = this._tmpid();
    var len = this._tmpid();
    var arr = this._tmpid();
    frame = frame.push();
    this._emitLine('frame = frame.push();');
    this._emit("var " + arr + " = ");
    this._compileExpression(node.arr, frame);
    this._emitLine(';');
    this._emit("if(" + arr + ") {");
    this._emitLine(arr + ' = runtime.fromIterator(' + arr + ');');

    // If multiple names are passed, we need to bind them
    // appropriately
    if (node.name instanceof nodes.Array) {
      this._emitLine("var " + i + ";");

      // The object could be an arroy or object. Note that the
      // body of the loop is duplicated for each condition, but
      // we are optimizing for speed over size.
      this._emitLine("if(runtime.isArray(" + arr + ")) {");
      this._emitLine("var " + len + " = " + arr + ".length;");
      this._emitLine("for(" + i + "=0; " + i + " < " + arr + ".length; " + i + "++) {");

      // Bind each declared var
      node.name.children.forEach(function (child, u) {
        var tid = _this10._tmpid();
        _this10._emitLine("var " + tid + " = " + arr + "[" + i + "][" + u + "];");
        _this10._emitLine("frame.set(\"" + child + "\", " + arr + "[" + i + "][" + u + "]);");
        frame.set(node.name.children[u].value, tid);
      });
      this._emitLoopBindings(node, arr, i, len);
      this._withScopedSyntax(function () {
        _this10.compile(node.body, frame);
      });
      this._emitLine('}');
      this._emitLine('} else {');
      // Iterate over the key/values of an object
      var _node$name$children = node.name.children,
        key = _node$name$children[0],
        val = _node$name$children[1];
      var k = this._tmpid();
      var v = this._tmpid();
      frame.set(key.value, k);
      frame.set(val.value, v);
      this._emitLine(i + " = -1;");
      this._emitLine("var " + len + " = runtime.keys(" + arr + ").length;");
      this._emitLine("for(var " + k + " in " + arr + ") {");
      this._emitLine(i + "++;");
      this._emitLine("var " + v + " = " + arr + "[" + k + "];");
      this._emitLine("frame.set(\"" + key.value + "\", " + k + ");");
      this._emitLine("frame.set(\"" + val.value + "\", " + v + ");");
      this._emitLoopBindings(node, arr, i, len);
      this._withScopedSyntax(function () {
        _this10.compile(node.body, frame);
      });
      this._emitLine('}');
      this._emitLine('}');
    } else {
      // Generate a typical array iteration
      var _v = this._tmpid();
      frame.set(node.name.value, _v);
      this._emitLine("var " + len + " = " + arr + ".length;");
      this._emitLine("for(var " + i + "=0; " + i + " < " + arr + ".length; " + i + "++) {");
      this._emitLine("var " + _v + " = " + arr + "[" + i + "];");
      this._emitLine("frame.set(\"" + node.name.value + "\", " + _v + ");");
      this._emitLoopBindings(node, arr, i, len);
      this._withScopedSyntax(function () {
        _this10.compile(node.body, frame);
      });
      this._emitLine('}');
    }
    this._emitLine('}');
    if (node.else_) {
      this._emitLine('if (!' + len + ') {');
      this.compile(node.else_, frame);
      this._emitLine('}');
    }
    this._emitLine('frame = frame.pop();');
  };
  _proto._compileAsyncLoop = function _compileAsyncLoop(node, frame, parallel) {
    var _this11 = this;
    // This shares some code with the For tag, but not enough to
    // worry about. This iterates across an object asynchronously,
    // but not in parallel.

    var i = this._tmpid();
    var len = this._tmpid();
    var arr = this._tmpid();
    var asyncMethod = parallel ? 'asyncAll' : 'asyncEach';
    frame = frame.push();
    this._emitLine('frame = frame.push();');
    this._emit('var ' + arr + ' = runtime.fromIterator(');
    this._compileExpression(node.arr, frame);
    this._emitLine(');');
    if (node.name instanceof nodes.Array) {
      var arrayLen = node.name.children.length;
      this._emit("runtime." + asyncMethod + "(" + arr + ", " + arrayLen + ", function(");
      node.name.children.forEach(function (name) {
        _this11._emit(name.value + ",");
      });
      this._emit(i + ',' + len + ',next) {');
      node.name.children.forEach(function (name) {
        var id = name.value;
        frame.set(id, id);
        _this11._emitLine("frame.set(\"" + id + "\", " + id + ");");
      });
    } else {
      var id = node.name.value;
      this._emitLine("runtime." + asyncMethod + "(" + arr + ", 1, function(" + id + ", " + i + ", " + len + ",next) {");
      this._emitLine('frame.set("' + id + '", ' + id + ');');
      frame.set(id, id);
    }
    this._emitLoopBindings(node, arr, i, len);
    this._withScopedSyntax(function () {
      var buf;
      if (parallel) {
        buf = _this11._pushBuffer();
      }
      _this11.compile(node.body, frame);
      _this11._emitLine('next(' + i + (buf ? ',' + buf : '') + ');');
      if (parallel) {
        _this11._popBuffer();
      }
    });
    var output = this._tmpid();
    this._emitLine('}, ' + this._makeCallback(output));
    this._addScopeLevel();
    if (parallel) {
      this._emitLine(this.buffer + ' += ' + output + ';');
    }
    if (node.else_) {
      this._emitLine('if (!' + arr + '.length) {');
      this.compile(node.else_, frame);
      this._emitLine('}');
    }
    this._emitLine('frame = frame.pop();');
  };
  _proto.compileAsyncEach = function compileAsyncEach(node, frame) {
    this._compileAsyncLoop(node, frame);
  };
  _proto.compileAsyncAll = function compileAsyncAll(node, frame) {
    this._compileAsyncLoop(node, frame, true);
  };
  _proto._compileMacro = function _compileMacro(node, frame) {
    var _this12 = this;
    var args = [];
    var kwargs = null;
    var funcId = 'macro_' + this._tmpid();
    var keepFrame = frame !== undefined;

    // Type check the definition of the args
    node.args.children.forEach(function (arg, i) {
      if (i === node.args.children.length - 1 && arg instanceof nodes.Dict) {
        kwargs = arg;
      } else {
        _this12.assertType(arg, nodes.Symbol);
        args.push(arg);
      }
    });
    var realNames = [].concat(args.map(function (n) {
      return "l_" + n.value;
    }), ['kwargs']);

    // Quoted argument names
    var argNames = args.map(function (n) {
      return "\"" + n.value + "\"";
    });
    var kwargNames = (kwargs && kwargs.children || []).map(function (n) {
      return "\"" + n.key.value + "\"";
    });

    // We pass a function to makeMacro which destructures the
    // arguments so support setting positional args with keywords
    // args and passing keyword args as positional args
    // (essentially default values). See runtime.js.
    var currFrame;
    if (keepFrame) {
      currFrame = frame.push(true);
    } else {
      currFrame = new Frame();
    }
    this._emitLines("var " + funcId + " = runtime.makeMacro(", "[" + argNames.join(', ') + "], ", "[" + kwargNames.join(', ') + "], ", "function (" + realNames.join(', ') + ") {", 'var callerFrame = frame;', 'frame = ' + (keepFrame ? 'frame.push(true);' : 'new runtime.Frame();'), 'kwargs = kwargs || {};', 'if (Object.prototype.hasOwnProperty.call(kwargs, "caller")) {', 'frame.set("caller", kwargs.caller); }');

    // Expose the arguments to the template. Don't need to use
    // random names because the function
    // will create a new run-time scope for us
    args.forEach(function (arg) {
      _this12._emitLine("frame.set(\"" + arg.value + "\", l_" + arg.value + ");");
      currFrame.set(arg.value, "l_" + arg.value);
    });

    // Expose the keyword arguments
    if (kwargs) {
      kwargs.children.forEach(function (pair) {
        var name = pair.key.value;
        _this12._emit("frame.set(\"" + name + "\", ");
        _this12._emit("Object.prototype.hasOwnProperty.call(kwargs, \"" + name + "\")");
        _this12._emit(" ? kwargs[\"" + name + "\"] : ");
        _this12._compileExpression(pair.value, currFrame);
        _this12._emit(');');
      });
    }
    var bufferId = this._pushBuffer();
    this._withScopedSyntax(function () {
      _this12.compile(node.body, currFrame);
    });
    this._emitLine('frame = ' + (keepFrame ? 'frame.pop();' : 'callerFrame;'));
    this._emitLine("return new runtime.SafeString(" + bufferId + ");");
    this._emitLine('});');
    this._popBuffer();
    return funcId;
  };
  _proto.compileMacro = function compileMacro(node, frame) {
    var funcId = this._compileMacro(node);

    // Expose the macro to the templates
    var name = node.name.value;
    frame.set(name, funcId);
    if (frame.parent) {
      this._emitLine("frame.set(\"" + name + "\", " + funcId + ");");
    } else {
      if (node.name.value.charAt(0) !== '_') {
        this._emitLine("context.addExport(\"" + name + "\");");
      }
      this._emitLine("context.setVariable(\"" + name + "\", " + funcId + ");");
    }
  };
  _proto.compileCaller = function compileCaller(node, frame) {
    // basically an anonymous "macro expression"
    this._emit('(function (){');
    var funcId = this._compileMacro(node, frame);
    this._emit("return " + funcId + ";})()");
  };
  _proto._compileGetTemplate = function _compileGetTemplate(node, frame, eagerCompile, ignoreMissing) {
    var parentTemplateId = this._tmpid();
    var parentName = this._templateName();
    var cb = this._makeCallback(parentTemplateId);
    var eagerCompileArg = eagerCompile ? 'true' : 'false';
    var ignoreMissingArg = ignoreMissing ? 'true' : 'false';
    this._emit('env.getTemplate(');
    this._compileExpression(node.template, frame);
    this._emitLine(", " + eagerCompileArg + ", " + parentName + ", " + ignoreMissingArg + ", " + cb);
    return parentTemplateId;
  };
  _proto.compileImport = function compileImport(node, frame) {
    var target = node.target.value;
    var id = this._compileGetTemplate(node, frame, false, false);
    this._addScopeLevel();
    this._emitLine(id + '.getExported(' + (node.withContext ? 'context.getVariables(), frame, ' : '') + this._makeCallback(id));
    this._addScopeLevel();
    frame.set(target, id);
    if (frame.parent) {
      this._emitLine("frame.set(\"" + target + "\", " + id + ");");
    } else {
      this._emitLine("context.setVariable(\"" + target + "\", " + id + ");");
    }
  };
  _proto.compileFromImport = function compileFromImport(node, frame) {
    var _this13 = this;
    var importedId = this._compileGetTemplate(node, frame, false, false);
    this._addScopeLevel();
    this._emitLine(importedId + '.getExported(' + (node.withContext ? 'context.getVariables(), frame, ' : '') + this._makeCallback(importedId));
    this._addScopeLevel();
    node.names.children.forEach(function (nameNode) {
      var name;
      var alias;
      var id = _this13._tmpid();
      if (nameNode instanceof nodes.Pair) {
        name = nameNode.key.value;
        alias = nameNode.value.value;
      } else {
        name = nameNode.value;
        alias = name;
      }
      _this13._emitLine("if(Object.prototype.hasOwnProperty.call(" + importedId + ", \"" + name + "\")) {");
      _this13._emitLine("var " + id + " = " + importedId + "." + name + ";");
      _this13._emitLine('} else {');
      _this13._emitLine("cb(new Error(\"cannot import '" + name + "'\")); return;");
      _this13._emitLine('}');
      frame.set(alias, id);
      if (frame.parent) {
        _this13._emitLine("frame.set(\"" + alias + "\", " + id + ");");
      } else {
        _this13._emitLine("context.setVariable(\"" + alias + "\", " + id + ");");
      }
    });
  };
  _proto.compileBlock = function compileBlock(node) {
    var id = this._tmpid();

    // If we are executing outside a block (creating a top-level
    // block), we really don't want to execute its code because it
    // will execute twice: once when the child template runs and
    // again when the parent template runs. Note that blocks
    // within blocks will *always* execute immediately *and*
    // wherever else they are invoked (like used in a parent
    // template). This may have behavioral differences from jinja
    // because blocks can have side effects, but it seems like a
    // waste of performance to always execute huge top-level
    // blocks twice
    if (!this.inBlock) {
      this._emit('(parentTemplate ? function(e, c, f, r, cb) { cb(""); } : ');
    }
    this._emit("context.getBlock(\"" + node.name.value + "\")");
    if (!this.inBlock) {
      this._emit(')');
    }
    this._emitLine('(env, context, frame, runtime, ' + this._makeCallback(id));
    this._emitLine(this.buffer + " += " + id + ";");
    this._addScopeLevel();
  };
  _proto.compileSuper = function compileSuper(node, frame) {
    var name = node.blockName.value;
    var id = node.symbol.value;
    var cb = this._makeCallback(id);
    this._emitLine("context.getSuper(env, \"" + name + "\", b_" + name + ", frame, runtime, " + cb);
    this._emitLine(id + " = runtime.markSafe(" + id + ");");
    this._addScopeLevel();
    frame.set(id, id);
  };
  _proto.compileExtends = function compileExtends(node, frame) {
    var k = this._tmpid();
    var parentTemplateId = this._compileGetTemplate(node, frame, true, false);

    // extends is a dynamic tag and can occur within a block like
    // `if`, so if this happens we need to capture the parent
    // template in the top-level scope
    this._emitLine("parentTemplate = " + parentTemplateId);
    this._emitLine("for(var " + k + " in parentTemplate.blocks) {");
    this._emitLine("context.addBlock(" + k + ", parentTemplate.blocks[" + k + "]);");
    this._emitLine('}');
    this._addScopeLevel();
  };
  _proto.compileInclude = function compileInclude(node, frame) {
    this._emitLine('var tasks = [];');
    this._emitLine('tasks.push(');
    this._emitLine('function(callback) {');
    var id = this._compileGetTemplate(node, frame, false, node.ignoreMissing);
    this._emitLine("callback(null," + id + ");});");
    this._emitLine('});');
    var id2 = this._tmpid();
    this._emitLine('tasks.push(');
    this._emitLine('function(template, callback){');
    this._emitLine('template.render(context.getVariables(), frame, ' + this._makeCallback(id2));
    this._emitLine('callback(null,' + id2 + ');});');
    this._emitLine('});');
    this._emitLine('tasks.push(');
    this._emitLine('function(result, callback){');
    this._emitLine(this.buffer + " += result;");
    this._emitLine('callback(null);');
    this._emitLine('});');
    this._emitLine('env.waterfall(tasks, function(){');
    this._addScopeLevel();
  };
  _proto.compileTemplateData = function compileTemplateData(node, frame) {
    this.compileLiteral(node, frame);
  };
  _proto.compileCapture = function compileCapture(node, frame) {
    var _this14 = this;
    // we need to temporarily override the current buffer id as 'output'
    // so the set block writes to the capture output instead of the buffer
    var buffer = this.buffer;
    this.buffer = 'output';
    this._emitLine('(function() {');
    this._emitLine('var output = "";');
    this._withScopedSyntax(function () {
      _this14.compile(node.body, frame);
    });
    this._emitLine('return output;');
    this._emitLine('})()');
    // and of course, revert back to the old buffer id
    this.buffer = buffer;
  };
  _proto.compileOutput = function compileOutput(node, frame) {
    var _this15 = this;
    var children = node.children;
    children.forEach(function (child) {
      // TemplateData is a special case because it is never
      // autoescaped, so simply output it for optimization
      if (child instanceof nodes.TemplateData) {
        if (child.value) {
          _this15._emit(_this15.buffer + " += ");
          _this15.compileLiteral(child, frame);
          _this15._emitLine(';');
        }
      } else {
        _this15._emit(_this15.buffer + " += runtime.suppressValue(");
        if (_this15.throwOnUndefined) {
          _this15._emit('runtime.ensureDefined(');
        }
        _this15.compile(child, frame);
        if (_this15.throwOnUndefined) {
          _this15._emit("," + node.lineno + "," + node.colno + ")");
        }
        _this15._emit(', env.opts.autoescape);\n');
      }
    });
  };
  _proto.compileRoot = function compileRoot(node, frame) {
    var _this16 = this;
    if (frame) {
      this.fail('compileRoot: root node can\'t have frame');
    }
    frame = new Frame();
    this._emitFuncBegin(node, 'root');
    this._emitLine('var parentTemplate = null;');
    this._compileChildren(node, frame);
    this._emitLine('if(parentTemplate) {');
    this._emitLine('parentTemplate.rootRenderFunc(env, context, frame, runtime, cb);');
    this._emitLine('} else {');
    this._emitLine("cb(null, " + this.buffer + ");");
    this._emitLine('}');
    this._emitFuncEnd(true);
    this.inBlock = true;
    var blockNames = [];
    var blocks = node.findAll(nodes.Block);
    blocks.forEach(function (block, i) {
      var name = block.name.value;
      if (blockNames.indexOf(name) !== -1) {
        throw new Error("Block \"" + name + "\" defined more than once.");
      }
      blockNames.push(name);
      _this16._emitFuncBegin(block, "b_" + name);
      var tmpFrame = new Frame();
      _this16._emitLine('var frame = frame.push(true);');
      _this16.compile(block.body, tmpFrame);
      _this16._emitFuncEnd();
    });
    this._emitLine('return {');
    blocks.forEach(function (block, i) {
      var blockName = "b_" + block.name.value;
      _this16._emitLine(blockName + ": " + blockName + ",");
    });
    this._emitLine('root: root\n};');
  };
  _proto.compile = function compile(node, frame) {
    var _compile = this['compile' + node.typename];
    if (_compile) {
      _compile.call(this, node, frame);
    } else {
      this.fail("compile: Cannot compile node: " + node.typename, node.lineno, node.colno);
    }
  };
  _proto.getCode = function getCode() {
    return this.codebuf.join('');
  };
  return Compiler;
}(Obj);
module.exports = {
  compile: function compile(src, asyncFilters, extensions, name, opts) {
    if (opts === void 0) {
      opts = {};
    }
    var c = new Compiler(name, opts.throwOnUndefined);

    // Run the extension preprocessors against the source.
    var preprocessors = (extensions || []).map(function (ext) {
      return ext.preprocess;
    }).filter(function (f) {
      return !!f;
    });
    var processedSrc = preprocessors.reduce(function (s, processor) {
      return processor(s);
    }, src);
    c.compile(transformer.transform(parser.parse(processedSrc, extensions, opts), asyncFilters, name));
    return c.getCode();
  },
  Compiler: Compiler
};