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