define(['exports', 'module', '../base', '../exception', '../utils', './code-gen'], function (exports, module, _base, _exception, _utils, _codeGen) {
  'use strict';

  var _interopRequire = function (obj) { return obj && obj.__esModule ? obj['default'] : obj; };

  var _Exception = _interopRequire(_exception);

  var _CodeGen = _interopRequire(_codeGen);

  function Literal(value) {
    this.value = value;
  }

  function JavaScriptCompiler() {}

  JavaScriptCompiler.prototype = {
    // PUBLIC API: You can override these methods in a subclass to provide
    // alternative compiled forms for name lookup and buffering semantics
    nameLookup: function nameLookup(parent, name /* , type*/) {
      if (JavaScriptCompiler.isValidJavaScriptVariableName(name)) {
        return [parent, '.', name];
      } else {
        return [parent, '[\'', name, '\']'];
      }
    },
    depthedLookup: function depthedLookup(name) {
      return [this.aliasable('this.lookup'), '(depths, "', name, '")'];
    },

    compilerInfo: function compilerInfo() {
      var revision = _base.COMPILER_REVISION,
          versions = _base.REVISION_CHANGES[revision];
      return [revision, versions];
    },

    appendToBuffer: function appendToBuffer(source, location, explicit) {
      // Force a source as this simplifies the merge logic.
      if (!_utils.isArray(source)) {
        source = [source];
      }
      source = this.source.wrap(source, location);

      if (this.environment.isSimple) {
        return ['return ', source, ';'];
      } else if (explicit) {
        // This is a case where the buffer operation occurs as a child of another
        // construct, generally braces. We have to explicitly output these buffer
        // operations to ensure that the emitted code goes in the correct location.
        return ['buffer += ', source, ';'];
      } else {
        source.appendToBuffer = true;
        return source;
      }
    },

    initializeBuffer: function initializeBuffer() {
      return this.quotedString('');
    },
    // END PUBLIC API

    compile: function compile(environment, options, context, asObject) {
      this.environment = environment;
      this.options = options;
      this.stringParams = this.options.stringParams;
      this.trackIds = this.options.trackIds;
      this.precompile = !asObject;

      this.name = this.environment.name;
      this.isChild = !!context;
      this.context = context || {
        programs: [],
        environments: []
      };

      this.preamble();

      this.stackSlot = 0;
      this.stackVars = [];
      this.aliases = {};
      this.registers = { list: [] };
      this.hashes = [];
      this.compileStack = [];
      this.inlineStack = [];
      this.blockParams = [];

      this.compileChildren(environment, options);

      this.useDepths = this.useDepths || environment.useDepths || this.options.compat;
      this.useBlockParams = this.useBlockParams || environment.useBlockParams;

      var opcodes = environment.opcodes,
          opcode = undefined,
          firstLoc = undefined,
          i = undefined,
          l = undefined;

      for (i = 0, l = opcodes.length; i < l; i++) {
        opcode = opcodes[i];

        this.source.currentLocation = opcode.loc;
        firstLoc = firstLoc || opcode.loc;
        this[opcode.opcode].apply(this, opcode.args);
      }

      // Flush any trailing content that might be pending.
      this.source.currentLocation = firstLoc;
      this.pushSource('');

      /* istanbul ignore next */
      if (this.stackSlot || this.inlineStack.length || this.compileStack.length) {
        throw new _Exception('Compile completed with content left on stack');
      }

      var fn = this.createFunctionContext(asObject);
      if (!this.isChild) {
        var ret = {
          compiler: this.compilerInfo(),
          main: fn
        };
        var programs = this.context.programs;
        for (i = 0, l = programs.length; i < l; i++) {
          if (programs[i]) {
            ret[i] = programs[i];
          }
        }

        if (this.environment.usePartial) {
          ret.usePartial = true;
        }
        if (this.options.data) {
          ret.useData = true;
        }
        if (this.useDepths) {
          ret.useDepths = true;
        }
        if (this.useBlockParams) {
          ret.useBlockParams = true;
        }
        if (this.options.compat) {
          ret.compat = true;
        }

        if (!asObject) {
          ret.compiler = JSON.stringify(ret.compiler);

          this.source.currentLocation = { start: { line: 1, column: 0 } };
          ret = this.objectLiteral(ret);

          if (options.srcName) {
            ret = ret.toStringWithSourceMap({ file: options.destName });
            ret.map = ret.map && ret.map.toString();
          } else {
            ret = ret.toString();
          }
        } else {
          ret.compilerOptions = this.options;
        }

        return ret;
      } else {
        return fn;
      }
    },

    preamble: function preamble() {
      // track the last context pushed into place to allow skipping the
      // getContext opcode when it would be a noop
      this.lastContext = 0;
      this.source = new _CodeGen(this.options.srcName);
    },

    createFunctionContext: function createFunctionContext(asObject) {
      var varDeclarations = '';

      var locals = this.stackVars.concat(this.registers.list);
      if (locals.length > 0) {
        varDeclarations += ', ' + locals.join(', ');
      }

      // Generate minimizer alias mappings
      //
      // When using true SourceNodes, this will update all references to the given alias
      // as the source nodes are reused in situ. For the non-source node compilation mode,
      // aliases will not be used, but this case is already being run on the client and
      // we aren't concern about minimizing the template size.
      var aliasCount = 0;
      for (var alias in this.aliases) {
        // eslint-disable-line guard-for-in
        var node = this.aliases[alias];

        if (this.aliases.hasOwnProperty(alias) && node.children && node.referenceCount > 1) {
          varDeclarations += ', alias' + ++aliasCount + '=' + alias;
          node.children[0] = 'alias' + aliasCount;
        }
      }

      var params = ['depth0', 'helpers', 'partials', 'data'];

      if (this.useBlockParams || this.useDepths) {
        params.push('blockParams');
      }
      if (this.useDepths) {
        params.push('depths');
      }

      // Perform a second pass over the output to merge content when possible
      var source = this.mergeSource(varDeclarations);

      if (asObject) {
        params.push(source);

        return Function.apply(this, params);
      } else {
        return this.source.wrap(['function(', params.join(','), ') {\n  ', source, '}']);
      }
    },
    mergeSource: function mergeSource(varDeclarations) {
      var isSimple = this.environment.isSimple,
          appendOnly = !this.forceBuffer,
          appendFirst = undefined,
          sourceSeen = undefined,
          bufferStart = undefined,
          bufferEnd = undefined;
      this.source.each(function (line) {
        if (line.appendToBuffer) {
          if (bufferStart) {
            line.prepend('  + ');
          } else {
            bufferStart = line;
          }
          bufferEnd = line;
        } else {
          if (bufferStart) {
            if (!sourceSeen) {
              appendFirst = true;
            } else {
              bufferStart.prepend('buffer += ');
            }
            bufferEnd.add(';');
            bufferStart = bufferEnd = undefined;
          }

          sourceSeen = true;
          if (!isSimple) {
            appendOnly = false;
          }
        }
      });

      if (appendOnly) {
        if (bufferStart) {
          bufferStart.prepend('return ');
          bufferEnd.add(';');
        } else if (!sourceSeen) {
          this.source.push('return "";');
        }
      } else {
        varDeclarations += ', buffer = ' + (appendFirst ? '' : this.initializeBuffer());

        if (bufferStart) {
          bufferStart.prepend('return buffer + ');
          bufferEnd.add(';');
        } else {
          this.source.push('return buffer;');
        }
      }

      if (varDeclarations) {
        this.source.prepend('var ' + varDeclarations.substring(2) + (appendFirst ? '' : ';\n'));
      }

      return this.source.merge();
    },

    // [blockValue]
    //
    // On stack, before: hash, inverse, program, value
    // On stack, after: return value of blockHelperMissing
    //
    // The purpose of this opcode is to take a block of the form
    // `{{#this.foo}}...{{/this.foo}}`, resolve the value of `foo`, and
    // replace it on the stack with the result of properly
    // invoking blockHelperMissing.
    blockValue: function blockValue(name) {
      var blockHelperMissing = this.aliasable('helpers.blockHelperMissing'),
          params = [this.contextName(0)];
      this.setupHelperArgs(name, 0, params);

      var blockName = this.popStack();
      params.splice(1, 0, blockName);

      this.push(this.source.functionCall(blockHelperMissing, 'call', params));
    },

    // [ambiguousBlockValue]
    //
    // On stack, before: hash, inverse, program, value
    // Compiler value, before: lastHelper=value of last found helper, if any
    // On stack, after, if no lastHelper: same as [blockValue]
    // On stack, after, if lastHelper: value
    ambiguousBlockValue: function ambiguousBlockValue() {
      // We're being a bit cheeky and reusing the options value from the prior exec
      var blockHelperMissing = this.aliasable('helpers.blockHelperMissing'),
          params = [this.contextName(0)];
      this.setupHelperArgs('', 0, params, true);

      this.flushInline();

      var current = this.topStack();
      params.splice(1, 0, current);

      this.pushSource(['if (!', this.lastHelper, ') { ', current, ' = ', this.source.functionCall(blockHelperMissing, 'call', params), '}']);
    },

    // [appendContent]
    //
    // On stack, before: ...
    // On stack, after: ...
    //
    // Appends the string value of `content` to the current buffer
    appendContent: function appendContent(content) {
      if (this.pendingContent) {
        content = this.pendingContent + content;
      } else {
        this.pendingLocation = this.source.currentLocation;
      }

      this.pendingContent = content;
    },

    // [append]
    //
    // On stack, before: value, ...
    // On stack, after: ...
    //
    // Coerces `value` to a String and appends it to the current buffer.
    //
    // If `value` is truthy, or 0, it is coerced into a string and appended
    // Otherwise, the empty string is appended
    append: function append() {
      if (this.isInline()) {
        this.replaceStack(function (current) {
          return [' != null ? ', current, ' : ""'];
        });

        this.pushSource(this.appendToBuffer(this.popStack()));
      } else {
        var local = this.popStack();
        this.pushSource(['if (', local, ' != null) { ', this.appendToBuffer(local, undefined, true), ' }']);
        if (this.environment.isSimple) {
          this.pushSource(['else { ', this.appendToBuffer('\'\'', undefined, true), ' }']);
        }
      }
    },

    // [appendEscaped]
    //
    // On stack, before: value, ...
    // On stack, after: ...
    //
    // Escape `value` and append it to the buffer
    appendEscaped: function appendEscaped() {
      this.pushSource(this.appendToBuffer([this.aliasable('this.escapeExpression'), '(', this.popStack(), ')']));
    },

    // [getContext]
    //
    // On stack, before: ...
    // On stack, after: ...
    // Compiler value, after: lastContext=depth
    //
    // Set the value of the `lastContext` compiler value to the depth
    getContext: function getContext(depth) {
      this.lastContext = depth;
    },

    // [pushContext]
    //
    // On stack, before: ...
    // On stack, after: currentContext, ...
    //
    // Pushes the value of the current context onto the stack.
    pushContext: function pushContext() {
      this.pushStackLiteral(this.contextName(this.lastContext));
    },

    // [lookupOnContext]
    //
    // On stack, before: ...
    // On stack, after: currentContext[name], ...
    //
    // Looks up the value of `name` on the current context and pushes
    // it onto the stack.
    lookupOnContext: function lookupOnContext(parts, falsy, scoped) {
      var i = 0;

      if (!scoped && this.options.compat && !this.lastContext) {
        // The depthed query is expected to handle the undefined logic for the root level that
        // is implemented below, so we evaluate that directly in compat mode
        this.push(this.depthedLookup(parts[i++]));
      } else {
        this.pushContext();
      }

      this.resolvePath('context', parts, i, falsy);
    },

    // [lookupBlockParam]
    //
    // On stack, before: ...
    // On stack, after: blockParam[name], ...
    //
    // Looks up the value of `parts` on the given block param and pushes
    // it onto the stack.
    lookupBlockParam: function lookupBlockParam(blockParamId, parts) {
      this.useBlockParams = true;

      this.push(['blockParams[', blockParamId[0], '][', blockParamId[1], ']']);
      this.resolvePath('context', parts, 1);
    },

    // [lookupData]
    //
    // On stack, before: ...
    // On stack, after: data, ...
    //
    // Push the data lookup operator
    lookupData: function lookupData(depth, parts) {
      if (!depth) {
        this.pushStackLiteral('data');
      } else {
        this.pushStackLiteral('this.data(data, ' + depth + ')');
      }

      this.resolvePath('data', parts, 0, true);
    },

    resolvePath: function resolvePath(type, parts, i, falsy) {
      var _this = this;

      if (this.options.strict || this.options.assumeObjects) {
        this.push(strictLookup(this.options.strict, this, parts, type));
        return;
      }

      var len = parts.length;
      for (; i < len; i++) {
        /*eslint-disable no-loop-func */
        this.replaceStack(function (current) {
          var lookup = _this.nameLookup(current, parts[i], type);
          // We want to ensure that zero and false are handled properly if the context (falsy flag)
          // needs to have the special handling for these values.
          if (!falsy) {
            return [' != null ? ', lookup, ' : ', current];
          } else {
            // Otherwise we can use generic falsy handling
            return [' && ', lookup];
          }
        });
        /*eslint-enable no-loop-func */
      }
    },

    // [resolvePossibleLambda]
    //
    // On stack, before: value, ...
    // On stack, after: resolved value, ...
    //
    // If the `value` is a lambda, replace it on the stack by
    // the return value of the lambda
    resolvePossibleLambda: function resolvePossibleLambda() {
      this.push([this.aliasable('this.lambda'), '(', this.popStack(), ', ', this.contextName(0), ')']);
    },

    // [pushStringParam]
    //
    // On stack, before: ...
    // On stack, after: string, currentContext, ...
    //
    // This opcode is designed for use in string mode, which
    // provides the string value of a parameter along with its
    // depth rather than resolving it immediately.
    pushStringParam: function pushStringParam(string, type) {
      this.pushContext();
      this.pushString(type);

      // If it's a subexpression, the string result
      // will be pushed after this opcode.
      if (type !== 'SubExpression') {
        if (typeof string === 'string') {
          this.pushString(string);
        } else {
          this.pushStackLiteral(string);
        }
      }
    },

    emptyHash: function emptyHash(omitEmpty) {
      if (this.trackIds) {
        this.push('{}'); // hashIds
      }
      if (this.stringParams) {
        this.push('{}'); // hashContexts
        this.push('{}'); // hashTypes
      }
      this.pushStackLiteral(omitEmpty ? 'undefined' : '{}');
    },
    pushHash: function pushHash() {
      if (this.hash) {
        this.hashes.push(this.hash);
      }
      this.hash = { values: [], types: [], contexts: [], ids: [] };
    },
    popHash: function popHash() {
      var hash = this.hash;
      this.hash = this.hashes.pop();

      if (this.trackIds) {
        this.push(this.objectLiteral(hash.ids));
      }
      if (this.stringParams) {
        this.push(this.objectLiteral(hash.contexts));
        this.push(this.objectLiteral(hash.types));
      }

      this.push(this.objectLiteral(hash.values));
    },

    // [pushString]
    //
    // On stack, before: ...
    // On stack, after: quotedString(string), ...
    //
    // Push a quoted version of `string` onto the stack
    pushString: function pushString(string) {
      this.pushStackLiteral(this.quotedString(string));
    },

    // [pushLiteral]
    //
    // On stack, before: ...
    // On stack, after: value, ...
    //
    // Pushes a value onto the stack. This operation prevents
    // the compiler from creating a temporary variable to hold
    // it.
    pushLiteral: function pushLiteral(value) {
      this.pushStackLiteral(value);
    },

    // [pushProgram]
    //
    // On stack, before: ...
    // On stack, after: program(guid), ...
    //
    // Push a program expression onto the stack. This takes
    // a compile-time guid and converts it into a runtime-accessible
    // expression.
    pushProgram: function pushProgram(guid) {
      if (guid != null) {
        this.pushStackLiteral(this.programExpression(guid));
      } else {
        this.pushStackLiteral(null);
      }
    },

    // [invokeHelper]
    //
    // On stack, before: hash, inverse, program, params..., ...
    // On stack, after: result of helper invocation
    //
    // Pops off the helper's parameters, invokes the helper,
    // and pushes the helper's return value onto the stack.
    //
    // If the helper is not found, `helperMissing` is called.
    invokeHelper: function invokeHelper(paramSize, name, isSimple) {
      var nonHelper = this.popStack(),
          helper = this.setupHelper(paramSize, name),
          simple = isSimple ? [helper.name, ' || '] : '';

      var lookup = ['('].concat(simple, nonHelper);
      if (!this.options.strict) {
        lookup.push(' || ', this.aliasable('helpers.helperMissing'));
      }
      lookup.push(')');

      this.push(this.source.functionCall(lookup, 'call', helper.callParams));
    },

    // [invokeKnownHelper]
    //
    // On stack, before: hash, inverse, program, params..., ...
    // On stack, after: result of helper invocation
    //
    // This operation is used when the helper is known to exist,
    // so a `helperMissing` fallback is not required.
    invokeKnownHelper: function invokeKnownHelper(paramSize, name) {
      var helper = this.setupHelper(paramSize, name);
      this.push(this.source.functionCall(helper.name, 'call', helper.callParams));
    },

    // [invokeAmbiguous]
    //
    // On stack, before: hash, inverse, program, params..., ...
    // On stack, after: result of disambiguation
    //
    // This operation is used when an expression like `{{foo}}`
    // is provided, but we don't know at compile-time whether it
    // is a helper or a path.
    //
    // This operation emits more code than the other options,
    // and can be avoided by passing the `knownHelpers` and
    // `knownHelpersOnly` flags at compile-time.
    invokeAmbiguous: function invokeAmbiguous(name, helperCall) {
      this.useRegister('helper');

      var nonHelper = this.popStack();

      this.emptyHash();
      var helper = this.setupHelper(0, name, helperCall);

      var helperName = this.lastHelper = this.nameLookup('helpers', name, 'helper');

      var lookup = ['(', '(helper = ', helperName, ' || ', nonHelper, ')'];
      if (!this.options.strict) {
        lookup[0] = '(helper = ';
        lookup.push(' != null ? helper : ', this.aliasable('helpers.helperMissing'));
      }

      this.push(['(', lookup, helper.paramsInit ? ['),(', helper.paramsInit] : [], '),', '(typeof helper === ', this.aliasable('"function"'), ' ? ', this.source.functionCall('helper', 'call', helper.callParams), ' : helper))']);
    },

    // [invokePartial]
    //
    // On stack, before: context, ...
    // On stack after: result of partial invocation
    //
    // This operation pops off a context, invokes a partial with that context,
    // and pushes the result of the invocation back.
    invokePartial: function invokePartial(isDynamic, name, indent) {
      var params = [],
          options = this.setupParams(name, 1, params, false);

      if (isDynamic) {
        name = this.popStack();
        delete options.name;
      }

      if (indent) {
        options.indent = JSON.stringify(indent);
      }
      options.helpers = 'helpers';
      options.partials = 'partials';

      if (!isDynamic) {
        params.unshift(this.nameLookup('partials', name, 'partial'));
      } else {
        params.unshift(name);
      }

      if (this.options.compat) {
        options.depths = 'depths';
      }
      options = this.objectLiteral(options);
      params.push(options);

      this.push(this.source.functionCall('this.invokePartial', '', params));
    },

    // [assignToHash]
    //
    // On stack, before: value, ..., hash, ...
    // On stack, after: ..., hash, ...
    //
    // Pops a value off the stack and assigns it to the current hash
    assignToHash: function assignToHash(key) {
      var value = this.popStack(),
          context = undefined,
          type = undefined,
          id = undefined;

      if (this.trackIds) {
        id = this.popStack();
      }
      if (this.stringParams) {
        type = this.popStack();
        context = this.popStack();
      }

      var hash = this.hash;
      if (context) {
        hash.contexts[key] = context;
      }
      if (type) {
        hash.types[key] = type;
      }
      if (id) {
        hash.ids[key] = id;
      }
      hash.values[key] = value;
    },

    pushId: function pushId(type, name, child) {
      if (type === 'BlockParam') {
        this.pushStackLiteral('blockParams[' + name[0] + '].path[' + name[1] + ']' + (child ? ' + ' + JSON.stringify('.' + child) : ''));
      } else if (type === 'PathExpression') {
        this.pushString(name);
      } else if (type === 'SubExpression') {
        this.pushStackLiteral('true');
      } else {
        this.pushStackLiteral('null');
      }
    },

    // HELPERS

    compiler: JavaScriptCompiler,

    compileChildren: function compileChildren(environment, options) {
      var children = environment.children,
          child = undefined,
          compiler = undefined;

      for (var i = 0, l = children.length; i < l; i++) {
        child = children[i];
        compiler = new this.compiler(); // eslint-disable-line new-cap

        var index = this.matchExistingProgram(child);

        if (index == null) {
          this.context.programs.push(''); // Placeholder to prevent name conflicts for nested children
          index = this.context.programs.length;
          child.index = index;
          child.name = 'program' + index;
          this.context.programs[index] = compiler.compile(child, options, this.context, !this.precompile);
          this.context.environments[index] = child;

          this.useDepths = this.useDepths || compiler.useDepths;
          this.useBlockParams = this.useBlockParams || compiler.useBlockParams;
        } else {
          child.index = index;
          child.name = 'program' + index;

          this.useDepths = this.useDepths || child.useDepths;
          this.useBlockParams = this.useBlockParams || child.useBlockParams;
        }
      }
    },
    matchExistingProgram: function matchExistingProgram(child) {
      for (var i = 0, len = this.context.environments.length; i < len; i++) {
        var environment = this.context.environments[i];
        if (environment && environment.equals(child)) {
          return i;
        }
      }
    },

    programExpression: function programExpression(guid) {
      var child = this.environment.children[guid],
          programParams = [child.index, 'data', child.blockParams];

      if (this.useBlockParams || this.useDepths) {
        programParams.push('blockParams');
      }
      if (this.useDepths) {
        programParams.push('depths');
      }

      return 'this.program(' + programParams.join(', ') + ')';
    },

    useRegister: function useRegister(name) {
      if (!this.registers[name]) {
        this.registers[name] = true;
        this.registers.list.push(name);
      }
    },

    push: function push(expr) {
      if (!(expr instanceof Literal)) {
        expr = this.source.wrap(expr);
      }

      this.inlineStack.push(expr);
      return expr;
    },

    pushStackLiteral: function pushStackLiteral(item) {
      this.push(new Literal(item));
    },

    pushSource: function pushSource(source) {
      if (this.pendingContent) {
        this.source.push(this.appendToBuffer(this.source.quotedString(this.pendingContent), this.pendingLocation));
        this.pendingContent = undefined;
      }

      if (source) {
        this.source.push(source);
      }
    },

    replaceStack: function replaceStack(callback) {
      var prefix = ['('],
          stack = undefined,
          createdStack = undefined,
          usedLiteral = undefined;

      /* istanbul ignore next */
      if (!this.isInline()) {
        throw new _Exception('replaceStack on non-inline');
      }

      // We want to merge the inline statement into the replacement statement via ','
      var top = this.popStack(true);

      if (top instanceof Literal) {
        // Literals do not need to be inlined
        stack = [top.value];
        prefix = ['(', stack];
        usedLiteral = true;
      } else {
        // Get or create the current stack name for use by the inline
        createdStack = true;
        var _name = this.incrStack();

        prefix = ['((', this.push(_name), ' = ', top, ')'];
        stack = this.topStack();
      }

      var item = callback.call(this, stack);

      if (!usedLiteral) {
        this.popStack();
      }
      if (createdStack) {
        this.stackSlot--;
      }
      this.push(prefix.concat(item, ')'));
    },

    incrStack: function incrStack() {
      this.stackSlot++;
      if (this.stackSlot > this.stackVars.length) {
        this.stackVars.push('stack' + this.stackSlot);
      }
      return this.topStackName();
    },
    topStackName: function topStackName() {
      return 'stack' + this.stackSlot;
    },
    flushInline: function flushInline() {
      var inlineStack = this.inlineStack;
      this.inlineStack = [];
      for (var i = 0, len = inlineStack.length; i < len; i++) {
        var entry = inlineStack[i];
        /* istanbul ignore if */
        if (entry instanceof Literal) {
          this.compileStack.push(entry);
        } else {
          var stack = this.incrStack();
          this.pushSource([stack, ' = ', entry, ';']);
          this.compileStack.push(stack);
        }
      }
    },
    isInline: function isInline() {
      return this.inlineStack.length;
    },

    popStack: function popStack(wrapped) {
      var inline = this.isInline(),
          item = (inline ? this.inlineStack : this.compileStack).pop();

      if (!wrapped && item instanceof Literal) {
        return item.value;
      } else {
        if (!inline) {
          /* istanbul ignore next */
          if (!this.stackSlot) {
            throw new _Exception('Invalid stack pop');
          }
          this.stackSlot--;
        }
        return item;
      }
    },

    topStack: function topStack() {
      var stack = this.isInline() ? this.inlineStack : this.compileStack,
          item = stack[stack.length - 1];

      /* istanbul ignore if */
      if (item instanceof Literal) {
        return item.value;
      } else {
        return item;
      }
    },

    contextName: function contextName(context) {
      if (this.useDepths && context) {
        return 'depths[' + context + ']';
      } else {
        return 'depth' + context;
      }
    },

    quotedString: function quotedString(str) {
      return this.source.quotedString(str);
    },

    objectLiteral: function objectLiteral(obj) {
      return this.source.objectLiteral(obj);
    },

    aliasable: function aliasable(name) {
      var ret = this.aliases[name];
      if (ret) {
        ret.referenceCount++;
        return ret;
      }

      ret = this.aliases[name] = this.source.wrap(name);
      ret.aliasable = true;
      ret.referenceCount = 1;

      return ret;
    },

    setupHelper: function setupHelper(paramSize, name, blockHelper) {
      var params = [],
          paramsInit = this.setupHelperArgs(name, paramSize, params, blockHelper);
      var foundHelper = this.nameLookup('helpers', name, 'helper');

      return {
        params: params,
        paramsInit: paramsInit,
        name: foundHelper,
        callParams: [this.contextName(0)].concat(params)
      };
    },

    setupParams: function setupParams(helper, paramSize, params) {
      var options = {},
          contexts = [],
          types = [],
          ids = [],
          param = undefined;

      options.name = this.quotedString(helper);
      options.hash = this.popStack();

      if (this.trackIds) {
        options.hashIds = this.popStack();
      }
      if (this.stringParams) {
        options.hashTypes = this.popStack();
        options.hashContexts = this.popStack();
      }

      var inverse = this.popStack(),
          program = this.popStack();

      // Avoid setting fn and inverse if neither are set. This allows
      // helpers to do a check for `if (options.fn)`
      if (program || inverse) {
        options.fn = program || 'this.noop';
        options.inverse = inverse || 'this.noop';
      }

      // The parameters go on to the stack in order (making sure that they are evaluated in order)
      // so we need to pop them off the stack in reverse order
      var i = paramSize;
      while (i--) {
        param = this.popStack();
        params[i] = param;

        if (this.trackIds) {
          ids[i] = this.popStack();
        }
        if (this.stringParams) {
          types[i] = this.popStack();
          contexts[i] = this.popStack();
        }
      }

      if (this.trackIds) {
        options.ids = this.source.generateArray(ids);
      }
      if (this.stringParams) {
        options.types = this.source.generateArray(types);
        options.contexts = this.source.generateArray(contexts);
      }

      if (this.options.data) {
        options.data = 'data';
      }
      if (this.useBlockParams) {
        options.blockParams = 'blockParams';
      }
      return options;
    },

    setupHelperArgs: function setupHelperArgs(helper, paramSize, params, useRegister) {
      var options = this.setupParams(helper, paramSize, params, true);
      options = this.objectLiteral(options);
      if (useRegister) {
        this.useRegister('options');
        params.push('options');
        return ['options=', options];
      } else {
        params.push(options);
        return '';
      }
    }
  };

  (function () {
    var reservedWords = ('break else new var' + ' case finally return void' + ' catch for switch while' + ' continue function this with' + ' default if throw' + ' delete in try' + ' do instanceof typeof' + ' abstract enum int short' + ' boolean export interface static' + ' byte extends long super' + ' char final native synchronized' + ' class float package throws' + ' const goto private transient' + ' debugger implements protected volatile' + ' double import public let yield await' + ' null true false').split(' ');

    var compilerWords = JavaScriptCompiler.RESERVED_WORDS = {};

    for (var i = 0, l = reservedWords.length; i < l; i++) {
      compilerWords[reservedWords[i]] = true;
    }
  })();

  JavaScriptCompiler.isValidJavaScriptVariableName = function (name) {
    return !JavaScriptCompiler.RESERVED_WORDS[name] && /^[a-zA-Z_$][0-9a-zA-Z_$]*$/.test(name);
  };

  function strictLookup(requireTerminal, compiler, parts, type) {
    var stack = compiler.popStack(),
        i = 0,
        len = parts.length;
    if (requireTerminal) {
      len--;
    }

    for (; i < len; i++) {
      stack = compiler.nameLookup(stack, parts[i], type);
    }

    if (requireTerminal) {
      return [compiler.aliasable('this.strict'), '(', stack, ', ', compiler.quotedString(parts[i]), ')'];
    } else {
      return stack;
    }
  }

  module.exports = JavaScriptCompiler;
});