gecko/toolkit/devtools/acorn/walk.js

314 lines
11 KiB
JavaScript

// AST walker module for Mozilla Parser API compatible trees
(function(mod) {
if (typeof exports == "object" && typeof module == "object") return mod(exports); // CommonJS
if (typeof define == "function" && define.amd) return define(["exports"], mod); // AMD
mod((this.acorn || (this.acorn = {})).walk = {}); // Plain browser env
})(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.base;
function c(node, st, override) {
var type = override || node.type, found = visitors[type];
base[type](node, st, c);
if (found) found(node, st);
}
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 = funcs ? exports.make(funcs, base) : base;
function c(node, st, override) {
visitor[override || node.type](node, st, c);
}
c(node, state);
};
function makeTest(test) {
if (typeof test == "string")
return function(type) { return type == test; };
else if (!test)
return function() { return true; };
else
return test;
}
function Found(node, state) { this.node = node; this.state = 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.
exports.findNodeAt = function(node, start, end, test, base, state) {
test = makeTest(test);
try {
if (!base) base = exports.base;
var c = function(node, st, override) {
var type = override || node.type;
if ((start == null || node.start <= start) &&
(end == null || node.end >= end))
base[type](node, st, c);
if (test(type, node) &&
(start == null || node.start == start) &&
(end == null || node.end == end))
throw new Found(node, st);
};
c(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.
exports.findNodeAround = function(node, pos, test, base, state) {
test = makeTest(test);
try {
if (!base) base = exports.base;
var c = function(node, st, override) {
var type = override || node.type;
if (node.start > pos || node.end < pos) return;
base[type](node, st, c);
if (test(type, node)) throw new Found(node, st);
};
c(node, state);
} catch (e) {
if (e instanceof Found) return e;
throw e;
}
};
// Find the outermost matching node after a given position.
exports.findNodeAfter = function(node, pos, test, base, state) {
test = makeTest(test);
try {
if (!base) base = exports.base;
var c = function(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);
base[type](node, st, c);
};
c(node, state);
} catch (e) {
if (e instanceof Found) return e;
throw e;
}
};
// Find the outermost matching node before a given position.
exports.findNodeBefore = function(node, pos, test, base, state) {
test = makeTest(test);
if (!base) base = exports.base;
var max;
var c = function(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);
base[type](node, st, c);
};
c(node, state);
return max;
};
// 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.base;
var visitor = {};
for (var type in base) visitor[type] = base[type];
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 = exports.base = {};
base.Program = base.BlockStatement = function(node, st, c) {
for (var i = 0; i < node.body.length; ++i)
c(node.body[i], st, "Statement");
};
base.Statement = skipThrough;
base.EmptyStatement = ignore;
base.ExpressionStatement = function(node, st, c) {
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) {
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 = 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");
}
};
base.ReturnStatement = function(node, st, c) {
if (node.argument) c(node.argument, st, "Expression");
};
base.ThrowStatement = function(node, st, c) {
c(node.argument, st, "Expression");
};
base.TryStatement = function(node, st, c) {
c(node.block, st, "Statement");
if (node.handler) c(node.handler.body, st, "ScopeBody");
if (node.finalizer) c(node.finalizer, st, "Statement");
};
base.WhileStatement = function(node, st, c) {
c(node.test, st, "Expression");
c(node.body, st, "Statement");
};
base.DoWhileStatement = base.WhileStatement;
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 = 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) {
c(node, st, "Function");
};
base.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");
}
};
base.Function = function(node, st, c) {
c(node.body, st, "ScopeBody");
};
base.ScopeBody = function(node, st, c) {
c(node, st, "Statement");
};
base.Expression = skipThrough;
base.ThisExpression = ignore;
base.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");
}
};
base.ObjectExpression = function(node, st, c) {
for (var i = 0; i < node.properties.length; ++i)
c(node.properties[i].value, st, "Expression");
};
base.FunctionExpression = base.FunctionDeclaration;
base.SequenceExpression = function(node, st, c) {
for (var i = 0; i < node.expressions.length; ++i)
c(node.expressions[i], st, "Expression");
};
base.UnaryExpression = base.UpdateExpression = function(node, st, c) {
c(node.argument, st, "Expression");
};
base.BinaryExpression = base.AssignmentExpression = base.LogicalExpression = function(node, st, c) {
c(node.left, st, "Expression");
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; i < node.arguments.length; ++i)
c(node.arguments[i], st, "Expression");
};
base.MemberExpression = function(node, st, c) {
c(node.object, st, "Expression");
if (node.computed) c(node.property, st, "Expression");
};
base.Identifier = base.Literal = ignore;
// A custom walker that keeps track of the scope chain and the
// variables defined in it.
function makeScope(prev, isCatch) {
return {vars: Object.create(null), prev: prev, isCatch: isCatch};
}
function normalScope(scope) {
while (scope.isCatch) scope = scope.prev;
return scope;
}
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 ? normalScope(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");
if (node.handler) {
var inner = makeScope(scope, true);
inner.vars[node.handler.param.name] = {type: "catch clause", node: node.handler.param};
c(node.handler.body, inner, "ScopeBody");
}
if (node.finalizer) c(node.finalizer, scope, "Statement");
},
VariableDeclaration: function(node, scope, c) {
var target = normalScope(scope);
for (var i = 0; i < node.declarations.length; ++i) {
var decl = node.declarations[i];
target.vars[decl.id.name] = {type: "var", node: decl.id};
if (decl.init) c(decl.init, scope, "Expression");
}
}
});
});