342 lines
12 KiB
JavaScript
342 lines
12 KiB
JavaScript
|
// 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,
|
||
|
|
// 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.
|
||
|
|
|
||
|
|
function simple(node, visitors, base, state, override) {
|
||
|
|
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)
|
||
|
|
})(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, base, state) {
|
||
|
|
if (!base) base = exports.base
|
||
|
|
var ancestors = []
|
||
|
|
;(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)
|
||
|
|
base[type](node, st, c)
|
||
|
|
if (found) found(node, st || ancestors, ancestors)
|
||
|
|
if (isNew) ancestors.pop()
|
||
|
|
})(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).
|
||
|
|
function recursive(node, state, funcs, base, override) {
|
||
|
|
var visitor = funcs ? exports.make(funcs, base) : base
|
||
|
|
;(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 };
|
||
|
|
|
||
|
|
// 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, base, state) {
|
||
|
|
test = makeTest(test)
|
||
|
|
if (!base) base = exports.base
|
||
|
|
try {
|
||
|
|
;(function c(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 ((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, base, state) {
|
||
|
|
test = makeTest(test)
|
||
|
|
if (!base) base = exports.base
|
||
|
|
try {
|
||
|
|
;(function c(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)
|
||
|
|
})(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, base, state) {
|
||
|
|
test = makeTest(test)
|
||
|
|
if (!base) base = exports.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)
|
||
|
|
base[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, base, state) {
|
||
|
|
test = makeTest(test)
|
||
|
|
if (!base) base = exports.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)
|
||
|
|
base[type](node, st, c)
|
||
|
|
})(node, state)
|
||
|
|
return max
|
||
|
|
}
|
||
|
|
|
||
|
|
// Fallback to an Object.create polyfill for older environments.
|
||
|
|
var create = Object.create || function(proto) {
|
||
|
|
function Ctor() {}
|
||
|
|
Ctor.prototype = proto
|
||
|
|
return new Ctor
|
||
|
|
}
|
||
|
|
|
||
|
|
// Used to create a custom walker. Will fill in all missing node
|
||
|
|
// type properties with the defaults.
|
||
|
|
function make(funcs, base) {
|
||
|
|
if (!base) base = exports.base
|
||
|
|
var visitor = create(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 = 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 = base.ParenthesizedExpression =
|
||
|
|
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 = 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 = 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) {
|
||
|
|
c(node.param, st, "Pattern")
|
||
|
|
c(node.body, st, "ScopeBody")
|
||
|
|
}
|
||
|
|
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; i < node.declarations.length; ++i)
|
||
|
|
c(node.declarations[i], 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; i < node.params.length; i++)
|
||
|
|
c(node.params[i], st, "Pattern")
|
||
|
|
c(node.body, st, node.expression ? "ScopeExpression" : "ScopeBody")
|
||
|
|
}
|
||
|
|
// FIXME drop these node types in next major version
|
||
|
|
// (They are awkward, and in ES6 every block can be a scope.)
|
||
|
|
base.ScopeBody = function (node, st, c) { return c(node, st, "Statement"); }
|
||
|
|
base.ScopeExpression = function (node, st, c) { return c(node, st, "Expression"); }
|
||
|
|
|
||
|
|
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; i < node.elements.length; ++i) {
|
||
|
|
var elt = node.elements[i]
|
||
|
|
if (elt) c(elt, st, "Pattern")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
base.ObjectPattern = function (node, st, c) {
|
||
|
|
for (var i = 0; i < node.properties.length; ++i)
|
||
|
|
c(node.properties[i].value, st, "Pattern")
|
||
|
|
}
|
||
|
|
|
||
|
|
base.Expression = skipThrough
|
||
|
|
base.ThisExpression = base.Super = base.MetaProperty = 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], st)
|
||
|
|
}
|
||
|
|
base.FunctionExpression = base.ArrowFunctionExpression = base.FunctionDeclaration
|
||
|
|
base.SequenceExpression = base.TemplateLiteral = 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.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; 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.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) {
|
||
|
|
c(node.source, st, "Expression")
|
||
|
|
}
|
||
|
|
base.ImportDeclaration = function (node, st, c) {
|
||
|
|
for (var i = 0; i < node.specifiers.length; i++)
|
||
|
|
c(node.specifiers[i], st)
|
||
|
|
c(node.source, st, "Expression")
|
||
|
|
}
|
||
|
|
base.ImportSpecifier = base.ImportDefaultSpecifier = base.ImportNamespaceSpecifier = base.Identifier = base.Literal = ignore
|
||
|
|
|
||
|
|
base.TaggedTemplateExpression = function (node, st, c) {
|
||
|
|
c(node.tag, st, "Expression")
|
||
|
|
c(node.quasi, st)
|
||
|
|
}
|
||
|
|
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")
|
||
|
|
for (var i = 0; i < node.body.body.length; i++)
|
||
|
|
c(node.body.body[i], st)
|
||
|
|
}
|
||
|
|
base.MethodDefinition = base.Property = function (node, st, c) {
|
||
|
|
if (node.computed) c(node.key, st, "Expression")
|
||
|
|
c(node.value, st, "Expression")
|
||
|
|
}
|
||
|
|
|
||
|
|
export { simple, ancestor, recursive, findNodeAt, findNodeAround, findNodeAfter, findNodeBefore, make, base };
|