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- // AST walker module for Mozilla Parser API compatible trees
- // 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 and
- // Statement, 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.
- function simple(node, visitors, baseVisitor, state, override) {
- if (!baseVisitor) { baseVisitor = base
- ; }(function c(node, st, override) {
- var type = override || node.type, found = visitors[type];
- baseVisitor[type](node, st, c);
- if (found) { found(node, st); }
- })(node, state, override);
- }
- // An ancestor walk keeps an array of ancestor nodes (including the
- // current node) and passes them to the callback as third parameter
- // (and also as state parameter when no other state is present).
- function ancestor(node, visitors, baseVisitor, state, override) {
- var ancestors = [];
- if (!baseVisitor) { baseVisitor = base
- ; }(function c(node, st, override) {
- var type = override || node.type, found = visitors[type];
- var isNew = node !== ancestors[ancestors.length - 1];
- if (isNew) { ancestors.push(node); }
- baseVisitor[type](node, st, c);
- if (found) { found(node, st || ancestors, ancestors); }
- if (isNew) { ancestors.pop(); }
- })(node, state, override);
- }
- // 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).
- function recursive(node, state, funcs, baseVisitor, override) {
- var visitor = funcs ? make(funcs, baseVisitor || undefined) : baseVisitor
- ;(function c(node, st, override) {
- visitor[override || node.type](node, st, c);
- })(node, state, override);
- }
- function makeTest(test) {
- if (typeof test === "string")
- { return function (type) { return type === test; } }
- else if (!test)
- { return function () { return true; } }
- else
- { return test }
- }
- var Found = function Found(node, state) { this.node = node; this.state = state; };
- // A full walk triggers the callback on each node
- function full(node, callback, baseVisitor, state, override) {
- if (!baseVisitor) { baseVisitor = base; }
- var last
- ;(function c(node, st, override) {
- var type = override || node.type;
- baseVisitor[type](node, st, c);
- if (last !== node) {
- callback(node, st, type);
- last = node;
- }
- })(node, state, override);
- }
- // An fullAncestor walk is like an ancestor walk, but triggers
- // the callback on each node
- function fullAncestor(node, callback, baseVisitor, state) {
- if (!baseVisitor) { baseVisitor = base; }
- var ancestors = [], last
- ;(function c(node, st, override) {
- var type = override || node.type;
- var isNew = node !== ancestors[ancestors.length - 1];
- if (isNew) { ancestors.push(node); }
- baseVisitor[type](node, st, c);
- if (last !== node) {
- callback(node, st || ancestors, ancestors, type);
- last = node;
- }
- if (isNew) { ancestors.pop(); }
- })(node, state);
- }
- // Find a node with a given start, end, and type (all are optional,
- // null can be used as wildcard). Returns a {node, state} object, or
- // undefined when it doesn't find a matching node.
- function findNodeAt(node, start, end, test, baseVisitor, state) {
- if (!baseVisitor) { baseVisitor = base; }
- test = makeTest(test);
- try {
- (function c(node, st, override) {
- var type = override || node.type;
- if ((start == null || node.start <= start) &&
- (end == null || node.end >= end))
- { baseVisitor[type](node, st, c); }
- if ((start == null || node.start === start) &&
- (end == null || node.end === end) &&
- test(type, node))
- { throw new Found(node, st) }
- })(node, state);
- } catch (e) {
- if (e instanceof Found) { return e }
- throw e
- }
- }
- // Find the innermost node of a given type that contains the given
- // position. Interface similar to findNodeAt.
- function findNodeAround(node, pos, test, baseVisitor, state) {
- test = makeTest(test);
- if (!baseVisitor) { baseVisitor = base; }
- try {
- (function c(node, st, override) {
- var type = override || node.type;
- if (node.start > pos || node.end < pos) { return }
- baseVisitor[type](node, st, c);
- if (test(type, node)) { throw new Found(node, st) }
- })(node, state);
- } catch (e) {
- if (e instanceof Found) { return e }
- throw e
- }
- }
- // Find the outermost matching node after a given position.
- function findNodeAfter(node, pos, test, baseVisitor, state) {
- test = makeTest(test);
- if (!baseVisitor) { baseVisitor = base; }
- try {
- (function c(node, st, override) {
- if (node.end < pos) { return }
- var type = override || node.type;
- if (node.start >= pos && test(type, node)) { throw new Found(node, st) }
- baseVisitor[type](node, st, c);
- })(node, state);
- } catch (e) {
- if (e instanceof Found) { return e }
- throw e
- }
- }
- // Find the outermost matching node before a given position.
- function findNodeBefore(node, pos, test, baseVisitor, state) {
- test = makeTest(test);
- if (!baseVisitor) { baseVisitor = base; }
- var max
- ;(function c(node, st, override) {
- if (node.start > pos) { return }
- var type = override || node.type;
- if (node.end <= pos && (!max || max.node.end < node.end) && test(type, node))
- { max = new Found(node, st); }
- baseVisitor[type](node, st, c);
- })(node, state);
- return max
- }
- // Used to create a custom walker. Will fill in all missing node
- // type properties with the defaults.
- function make(funcs, baseVisitor) {
- var visitor = Object.create(baseVisitor || base);
- for (var type in funcs) { visitor[type] = funcs[type]; }
- return visitor
- }
- function skipThrough(node, st, c) { c(node, st); }
- function ignore(_node, _st, _c) {}
- // Node walkers.
- var base = {};
- base.Program = base.BlockStatement = base.StaticBlock = function (node, st, c) {
- for (var i = 0, list = node.body; i < list.length; i += 1)
- {
- var stmt = list[i];
- c(stmt, st, "Statement");
- }
- };
- base.Statement = skipThrough;
- base.EmptyStatement = ignore;
- base.ExpressionStatement = base.ParenthesizedExpression = base.ChainExpression =
- function (node, st, c) { return c(node.expression, st, "Expression"); };
- base.IfStatement = function (node, st, c) {
- c(node.test, st, "Expression");
- c(node.consequent, st, "Statement");
- if (node.alternate) { c(node.alternate, st, "Statement"); }
- };
- base.LabeledStatement = function (node, st, c) { return c(node.body, st, "Statement"); };
- base.BreakStatement = base.ContinueStatement = ignore;
- base.WithStatement = function (node, st, c) {
- c(node.object, st, "Expression");
- c(node.body, st, "Statement");
- };
- base.SwitchStatement = function (node, st, c) {
- c(node.discriminant, st, "Expression");
- for (var i$1 = 0, list$1 = node.cases; i$1 < list$1.length; i$1 += 1) {
- var cs = list$1[i$1];
- if (cs.test) { c(cs.test, st, "Expression"); }
- for (var i = 0, list = cs.consequent; i < list.length; i += 1)
- {
- var cons = list[i];
- c(cons, st, "Statement");
- }
- }
- };
- base.SwitchCase = function (node, st, c) {
- if (node.test) { c(node.test, st, "Expression"); }
- for (var i = 0, list = node.consequent; i < list.length; i += 1)
- {
- var cons = list[i];
- c(cons, st, "Statement");
- }
- };
- base.ReturnStatement = base.YieldExpression = base.AwaitExpression = function (node, st, c) {
- if (node.argument) { c(node.argument, st, "Expression"); }
- };
- base.ThrowStatement = base.SpreadElement =
- function (node, st, c) { return c(node.argument, st, "Expression"); };
- base.TryStatement = function (node, st, c) {
- c(node.block, st, "Statement");
- if (node.handler) { c(node.handler, st); }
- if (node.finalizer) { c(node.finalizer, st, "Statement"); }
- };
- base.CatchClause = function (node, st, c) {
- if (node.param) { c(node.param, st, "Pattern"); }
- c(node.body, st, "Statement");
- };
- base.WhileStatement = base.DoWhileStatement = function (node, st, c) {
- c(node.test, st, "Expression");
- c(node.body, st, "Statement");
- };
- base.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");
- };
- base.ForInStatement = base.ForOfStatement = function (node, st, c) {
- c(node.left, st, "ForInit");
- c(node.right, st, "Expression");
- c(node.body, st, "Statement");
- };
- base.ForInit = function (node, st, c) {
- if (node.type === "VariableDeclaration") { c(node, st); }
- else { c(node, st, "Expression"); }
- };
- base.DebuggerStatement = ignore;
- base.FunctionDeclaration = function (node, st, c) { return c(node, st, "Function"); };
- base.VariableDeclaration = function (node, st, c) {
- for (var i = 0, list = node.declarations; i < list.length; i += 1)
- {
- var decl = list[i];
- c(decl, st);
- }
- };
- base.VariableDeclarator = function (node, st, c) {
- c(node.id, st, "Pattern");
- if (node.init) { c(node.init, st, "Expression"); }
- };
- base.Function = function (node, st, c) {
- if (node.id) { c(node.id, st, "Pattern"); }
- for (var i = 0, list = node.params; i < list.length; i += 1)
- {
- var param = list[i];
- c(param, st, "Pattern");
- }
- c(node.body, st, node.expression ? "Expression" : "Statement");
- };
- base.Pattern = function (node, st, c) {
- if (node.type === "Identifier")
- { c(node, st, "VariablePattern"); }
- else if (node.type === "MemberExpression")
- { c(node, st, "MemberPattern"); }
- else
- { c(node, st); }
- };
- base.VariablePattern = ignore;
- base.MemberPattern = skipThrough;
- base.RestElement = function (node, st, c) { return c(node.argument, st, "Pattern"); };
- base.ArrayPattern = function (node, st, c) {
- for (var i = 0, list = node.elements; i < list.length; i += 1) {
- var elt = list[i];
- if (elt) { c(elt, st, "Pattern"); }
- }
- };
- base.ObjectPattern = function (node, st, c) {
- for (var i = 0, list = node.properties; i < list.length; i += 1) {
- var prop = list[i];
- if (prop.type === "Property") {
- if (prop.computed) { c(prop.key, st, "Expression"); }
- c(prop.value, st, "Pattern");
- } else if (prop.type === "RestElement") {
- c(prop.argument, st, "Pattern");
- }
- }
- };
- base.Expression = skipThrough;
- base.ThisExpression = base.Super = base.MetaProperty = ignore;
- base.ArrayExpression = function (node, st, c) {
- for (var i = 0, list = node.elements; i < list.length; i += 1) {
- var elt = list[i];
- if (elt) { c(elt, st, "Expression"); }
- }
- };
- base.ObjectExpression = function (node, st, c) {
- for (var i = 0, list = node.properties; i < list.length; i += 1)
- {
- var prop = list[i];
- c(prop, st);
- }
- };
- base.FunctionExpression = base.ArrowFunctionExpression = base.FunctionDeclaration;
- base.SequenceExpression = function (node, st, c) {
- for (var i = 0, list = node.expressions; i < list.length; i += 1)
- {
- var expr = list[i];
- c(expr, st, "Expression");
- }
- };
- base.TemplateLiteral = function (node, st, c) {
- for (var i = 0, list = node.quasis; i < list.length; i += 1)
- {
- var quasi = list[i];
- c(quasi, st);
- }
- for (var i$1 = 0, list$1 = node.expressions; i$1 < list$1.length; i$1 += 1)
- {
- var expr = list$1[i$1];
- c(expr, st, "Expression");
- }
- };
- base.TemplateElement = ignore;
- base.UnaryExpression = base.UpdateExpression = function (node, st, c) {
- c(node.argument, st, "Expression");
- };
- base.BinaryExpression = base.LogicalExpression = function (node, st, c) {
- c(node.left, st, "Expression");
- c(node.right, st, "Expression");
- };
- base.AssignmentExpression = base.AssignmentPattern = function (node, st, c) {
- c(node.left, st, "Pattern");
- c(node.right, st, "Expression");
- };
- base.ConditionalExpression = function (node, st, c) {
- c(node.test, st, "Expression");
- c(node.consequent, st, "Expression");
- c(node.alternate, st, "Expression");
- };
- base.NewExpression = base.CallExpression = function (node, st, c) {
- c(node.callee, st, "Expression");
- if (node.arguments)
- { for (var i = 0, list = node.arguments; i < list.length; i += 1)
- {
- var arg = list[i];
- c(arg, st, "Expression");
- } }
- };
- base.MemberExpression = function (node, st, c) {
- c(node.object, st, "Expression");
- if (node.computed) { c(node.property, st, "Expression"); }
- };
- base.ExportNamedDeclaration = base.ExportDefaultDeclaration = function (node, st, c) {
- if (node.declaration)
- { c(node.declaration, st, node.type === "ExportNamedDeclaration" || node.declaration.id ? "Statement" : "Expression"); }
- if (node.source) { c(node.source, st, "Expression"); }
- };
- base.ExportAllDeclaration = function (node, st, c) {
- if (node.exported)
- { c(node.exported, st); }
- c(node.source, st, "Expression");
- };
- base.ImportDeclaration = function (node, st, c) {
- for (var i = 0, list = node.specifiers; i < list.length; i += 1)
- {
- var spec = list[i];
- c(spec, st);
- }
- c(node.source, st, "Expression");
- };
- base.ImportExpression = function (node, st, c) {
- c(node.source, st, "Expression");
- };
- base.ImportSpecifier = base.ImportDefaultSpecifier = base.ImportNamespaceSpecifier = base.Identifier = base.PrivateIdentifier = base.Literal = ignore;
- base.TaggedTemplateExpression = function (node, st, c) {
- c(node.tag, st, "Expression");
- c(node.quasi, st, "Expression");
- };
- base.ClassDeclaration = base.ClassExpression = function (node, st, c) { return c(node, st, "Class"); };
- base.Class = function (node, st, c) {
- if (node.id) { c(node.id, st, "Pattern"); }
- if (node.superClass) { c(node.superClass, st, "Expression"); }
- c(node.body, st);
- };
- base.ClassBody = function (node, st, c) {
- for (var i = 0, list = node.body; i < list.length; i += 1)
- {
- var elt = list[i];
- c(elt, st);
- }
- };
- base.MethodDefinition = base.PropertyDefinition = base.Property = function (node, st, c) {
- if (node.computed) { c(node.key, st, "Expression"); }
- if (node.value) { c(node.value, st, "Expression"); }
- };
- export { ancestor, base, findNodeAfter, findNodeAround, findNodeAt, findNodeBefore, full, fullAncestor, make, recursive, simple };
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