--- /dev/null
+// AST walker module for Mozilla Parser API compatible trees
+
+(function(exports) {
+ "use strict";
+
+ // A simple walk is one where you simply specify callbacks to be
+ // called on specific nodes. The last two arguments are optional. A
+ // simple use would be
+ //
+ // walk.simple(myTree, {
+ // Expression: function(node) { ... }
+ // });
+ //
+ // to do something with all expressions. All Parser API node types
+ // can be used to identify node types, as well as Expression,
+ // Statement, and ScopeBody, which denote categories of nodes.
+ //
+ // The base argument can be used to pass a custom (recursive)
+ // walker, and state can be used to give this walked an initial
+ // state.
+ exports.simple = function(node, visitors, base, state) {
+ if (!base) base = exports;
+ function c(node, st, override) {
+ var type = override || node.type, found = visitors[type];
+ if (found) found(node, st);
+ base[type](node, st, c);
+ }
+ c(node, state);
+ };
+
+ // A recursive walk is one where your functions override the default
+ // walkers. They can modify and replace the state parameter that's
+ // threaded through the walk, and can opt how and whether to walk
+ // their child nodes (by calling their third argument on these
+ // nodes).
+ exports.recursive = function(node, state, funcs, base) {
+ var visitor = exports.make(funcs, base);
+ function c(node, st, override) {
+ visitor[override || node.type](node, st, c);
+ }
+ c(node, state);
+ };
+
+ // Used to create a custom walker. Will fill in all missing node
+ // type properties with the defaults.
+ exports.make = function(funcs, base) {
+ if (!base) base = exports;
+ var visitor = {};
+ for (var type in base)
+ visitor[type] = funcs.hasOwnProperty(type) ? funcs[type] : base[type];
+ return visitor;
+ };
+
+ function skipThrough(node, st, c) { c(node, st); }
+ function ignore(node, st, c) {}
+
+ // Node walkers.
+
+ exports.Program = exports.BlockStatement = function(node, st, c) {
+ for (var i = 0; i < node.body.length; ++i)
+ c(node.body[i], st, "Statement");
+ };
+ exports.Statement = skipThrough;
+ exports.EmptyStatement = ignore;
+ exports.ExpressionStatement = function(node, st, c) {
+ c(node.expression, st, "Expression");
+ };
+ exports.IfStatement = function(node, st, c) {
+ c(node.test, st, "Expression");
+ c(node.consequent, st, "Statement");
+ if (node.alternate) c(node.alternate, st, "Statement");
+ };
+ exports.LabeledStatement = function(node, st, c) {
+ c(node.body, st, "Statement");
+ };
+ exports.BreakStatement = exports.ContinueStatement = ignore;
+ exports.WithStatement = function(node, st, c) {
+ c(node.object, st, "Expression");
+ c(node.body, st, "Statement");
+ };
+ exports.SwitchStatement = function(node, st, c) {
+ c(node.discriminant, st, "Expression");
+ for (var i = 0; i < node.cases.length; ++i) {
+ var cs = node.cases[i];
+ if (cs.test) c(cs.test, st, "Expression");
+ for (var j = 0; j < cs.consequent.length; ++j)
+ c(cs.consequent[j], st, "Statement");
+ }
+ };
+ exports.ReturnStatement = function(node, st, c) {
+ if (node.argument) c(node.argument, st, "Expression");
+ };
+ exports.ThrowStatement = function(node, st, c) {
+ c(node.argument, st, "Expression");
+ };
+ exports.TryStatement = function(node, st, c) {
+ c(node.block, st, "Statement");
+ for (var i = 0; i < node.handlers.length; ++i)
+ c(node.handlers[i].body, st, "ScopeBody");
+ if (node.finalizer) c(node.finalizer, st, "Statement");
+ };
+ exports.WhileStatement = function(node, st, c) {
+ c(node.test, st, "Expression");
+ c(node.body, st, "Statement");
+ };
+ exports.DoWhileStatement = exports.WhileStatement;
+ exports.ForStatement = function(node, st, c) {
+ if (node.init) c(node.init, st, "ForInit");
+ if (node.test) c(node.test, st, "Expression");
+ if (node.update) c(node.update, st, "Expression");
+ c(node.body, st, "Statement");
+ };
+ exports.ForInStatement = function(node, st, c) {
+ c(node.left, st, "ForInit");
+ c(node.right, st, "Expression");
+ c(node.body, st, "Statement");
+ };
+ exports.ForInit = function(node, st, c) {
+ if (node.type == "VariableDeclaration") c(node, st);
+ else c(node, st, "Expression");
+ };
+ exports.DebuggerStatement = ignore;
+
+ exports.FunctionDeclaration = function(node, st, c) {
+ c(node, st, "Function");
+ };
+ exports.VariableDeclaration = function(node, st, c) {
+ for (var i = 0; i < node.declarations.length; ++i) {
+ var decl = node.declarations[i];
+ if (decl.init) c(decl.init, st, "Expression");
+ }
+ };
+
+ exports.Function = function(node, st, c) {
+ c(node.body, st, "ScopeBody");
+ };
+ exports.ScopeBody = function(node, st, c) {
+ c(node, st, "Statement");
+ };
+
+ exports.Expression = skipThrough;
+ exports.ThisExpression = ignore;
+ exports.ArrayExpression = function(node, st, c) {
+ for (var i = 0; i < node.elements.length; ++i) {
+ var elt = node.elements[i];
+ if (elt) c(elt, st, "Expression");
+ }
+ };
+ exports.ObjectExpression = function(node, st, c) {
+ for (var i = 0; i < node.properties.length; ++i)
+ c(node.properties[i].value, st, "Expression");
+ };
+ exports.FunctionExpression = exports.FunctionDeclaration;
+ exports.SequenceExpression = function(node, st, c) {
+ for (var i = 0; i < node.expressions.length; ++i)
+ c(node.expressions[i], st, "Expression");
+ };
+ exports.UnaryExpression = exports.UpdateExpression = function(node, st, c) {
+ c(node.argument, st, "Expression");
+ };
+ exports.BinaryExpression = exports.AssignmentExpression = exports.LogicalExpression = function(node, st, c) {
+ c(node.left, st, "Expression");
+ c(node.right, st, "Expression");
+ };
+ exports.ConditionalExpression = function(node, st, c) {
+ c(node.test, st, "Expression");
+ c(node.consequent, st, "Expression");
+ c(node.alternate, st, "Expression");
+ };
+ exports.NewExpression = exports.CallExpression = function(node, st, c) {
+ c(node.callee, st, "Expression");
+ if (node.arguments) for (var i = 0; i < node.arguments.length; ++i)
+ c(node.arguments[i], st, "Expression");
+ };
+ exports.MemberExpression = function(node, st, c) {
+ c(node.object, st, "Expression");
+ if (node.computed) c(node.property, st, "Expression");
+ };
+ exports.Identifier = exports.Literal = ignore;
+
+ // A custom walker that keeps track of the scope chain and the
+ // variables defined in it.
+ function makeScope(prev) {
+ return {vars: Object.create(null), prev: prev};
+ }
+ exports.scopeVisitor = exports.make({
+ Function: function(node, scope, c) {
+ var inner = makeScope(scope);
+ for (var i = 0; i < node.params.length; ++i)
+ inner.vars[node.params[i].name] = {type: "argument", node: node.params[i]};
+ if (node.id) {
+ var decl = node.type == "FunctionDeclaration";
+ (decl ? scope : inner).vars[node.id.name] =
+ {type: decl ? "function" : "function name", node: node.id};
+ }
+ c(node.body, inner, "ScopeBody");
+ },
+ TryStatement: function(node, scope, c) {
+ c(node.block, scope, "Statement");
+ for (var i = 0; i < node.handlers.length; ++i) {
+ var handler = node.handlers[i], inner = makeScope(scope);
+ inner.vars[handler.param.name] = {type: "catch clause", node: handler.param};
+ c(handler.body, inner, "ScopeBody");
+ }
+ if (node.finalizer) c(node.finalizer, scope, "Statement");
+ },
+ VariableDeclaration: function(node, scope, c) {
+ for (var i = 0; i < node.declarations.length; ++i) {
+ var decl = node.declarations[i];
+ scope.vars[decl.id.name] = {type: "var", node: decl.id};
+ if (decl.init) c(decl.init, scope, "Expression");
+ }
+ }
+ });
+
+})(typeof exports == "undefined" ? acorn.walk = {} : exports);