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| // 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); | |