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Diffstat (limited to 'node_modules/acorn/src/walk/index.js')
-rw-r--r-- | node_modules/acorn/src/walk/index.js | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/node_modules/acorn/src/walk/index.js b/node_modules/acorn/src/walk/index.js new file mode 100644 index 000000000..e1c6ad409 --- /dev/null +++ b/node_modules/acorn/src/walk/index.js @@ -0,0 +1,342 @@ +// 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. + +export function simple(node, visitors, base, state, override) { + if (!base) base = exports.base + ;(function c(node, st, override) { + let 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). +export function ancestor(node, visitors, base, state) { + if (!base) base = exports.base + let ancestors = [] + ;(function c(node, st, override) { + let type = override || node.type, found = visitors[type] + let 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). +export function recursive(node, state, funcs, base, override) { + let 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 type => type == test + else if (!test) + return () => true + else + return test +} + +class Found { + constructor(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. +export function findNodeAt(node, start, end, test, base, state) { + test = makeTest(test) + if (!base) base = exports.base + try { + (function c(node, st, override) { + let 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. +export function findNodeAround(node, pos, test, base, state) { + test = makeTest(test) + if (!base) base = exports.base + try { + (function c(node, st, override) { + let 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. +export 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 + let 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. +export function findNodeBefore(node, pos, test, base, state) { + test = makeTest(test) + if (!base) base = exports.base + let max + ;(function c(node, st, override) { + if (node.start > pos) return + let 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. +const 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. +export function make(funcs, base) { + if (!base) base = exports.base + let visitor = create(base) + for (let type in funcs) visitor[type] = funcs[type] + return visitor +} + +function skipThrough(node, st, c) { c(node, st) } +function ignore(_node, _st, _c) {} + +// Node walkers. + +export const base = {} + +base.Program = base.BlockStatement = (node, st, c) => { + for (let i = 0; i < node.body.length; ++i) + c(node.body[i], st, "Statement") +} +base.Statement = skipThrough +base.EmptyStatement = ignore +base.ExpressionStatement = base.ParenthesizedExpression = + (node, st, c) => c(node.expression, st, "Expression") +base.IfStatement = (node, st, c) => { + c(node.test, st, "Expression") + c(node.consequent, st, "Statement") + if (node.alternate) c(node.alternate, st, "Statement") +} +base.LabeledStatement = (node, st, c) => c(node.body, st, "Statement") +base.BreakStatement = base.ContinueStatement = ignore +base.WithStatement = (node, st, c) => { + c(node.object, st, "Expression") + c(node.body, st, "Statement") +} +base.SwitchStatement = (node, st, c) => { + c(node.discriminant, st, "Expression") + for (let i = 0; i < node.cases.length; ++i) { + let cs = node.cases[i] + if (cs.test) c(cs.test, st, "Expression") + for (let j = 0; j < cs.consequent.length; ++j) + c(cs.consequent[j], st, "Statement") + } +} +base.ReturnStatement = base.YieldExpression = base.AwaitExpression = (node, st, c) => { + if (node.argument) c(node.argument, st, "Expression") +} +base.ThrowStatement = base.SpreadElement = + (node, st, c) => c(node.argument, st, "Expression") +base.TryStatement = (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 = (node, st, c) => { + c(node.param, st, "Pattern") + c(node.body, st, "ScopeBody") +} +base.WhileStatement = base.DoWhileStatement = (node, st, c) => { + c(node.test, st, "Expression") + c(node.body, st, "Statement") +} +base.ForStatement = (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 = (node, st, c) => { + c(node.left, st, "ForInit") + c(node.right, st, "Expression") + c(node.body, st, "Statement") +} +base.ForInit = (node, st, c) => { + if (node.type == "VariableDeclaration") c(node, st) + else c(node, st, "Expression") +} +base.DebuggerStatement = ignore + +base.FunctionDeclaration = (node, st, c) => c(node, st, "Function") +base.VariableDeclaration = (node, st, c) => { + for (let i = 0; i < node.declarations.length; ++i) + c(node.declarations[i], st) +} +base.VariableDeclarator = (node, st, c) => { + c(node.id, st, "Pattern") + if (node.init) c(node.init, st, "Expression") +} + +base.Function = (node, st, c) => { + if (node.id) c(node.id, st, "Pattern") + for (let 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 = (node, st, c) => c(node, st, "Statement") +base.ScopeExpression = (node, st, c) => c(node, st, "Expression") + +base.Pattern = (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 = (node, st, c) => c(node.argument, st, "Pattern") +base.ArrayPattern = (node, st, c) => { + for (let i = 0; i < node.elements.length; ++i) { + let elt = node.elements[i] + if (elt) c(elt, st, "Pattern") + } +} +base.ObjectPattern = (node, st, c) => { + for (let 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 = (node, st, c) => { + for (let i = 0; i < node.elements.length; ++i) { + let elt = node.elements[i] + if (elt) c(elt, st, "Expression") + } +} +base.ObjectExpression = (node, st, c) => { + for (let i = 0; i < node.properties.length; ++i) + c(node.properties[i], st) +} +base.FunctionExpression = base.ArrowFunctionExpression = base.FunctionDeclaration +base.SequenceExpression = base.TemplateLiteral = (node, st, c) => { + for (let i = 0; i < node.expressions.length; ++i) + c(node.expressions[i], st, "Expression") +} +base.UnaryExpression = base.UpdateExpression = (node, st, c) => { + c(node.argument, st, "Expression") +} +base.BinaryExpression = base.LogicalExpression = (node, st, c) => { + c(node.left, st, "Expression") + c(node.right, st, "Expression") +} +base.AssignmentExpression = base.AssignmentPattern = (node, st, c) => { + c(node.left, st, "Pattern") + c(node.right, st, "Expression") +} +base.ConditionalExpression = (node, st, c) => { + c(node.test, st, "Expression") + c(node.consequent, st, "Expression") + c(node.alternate, st, "Expression") +} +base.NewExpression = base.CallExpression = (node, st, c) => { + c(node.callee, st, "Expression") + if (node.arguments) for (let i = 0; i < node.arguments.length; ++i) + c(node.arguments[i], st, "Expression") +} +base.MemberExpression = (node, st, c) => { + c(node.object, st, "Expression") + if (node.computed) c(node.property, st, "Expression") +} +base.ExportNamedDeclaration = base.ExportDefaultDeclaration = (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 = (node, st, c) => { + c(node.source, st, "Expression") +} +base.ImportDeclaration = (node, st, c) => { + for (let 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 = (node, st, c) => { + c(node.tag, st, "Expression") + c(node.quasi, st) +} +base.ClassDeclaration = base.ClassExpression = (node, st, c) => c(node, st, "Class") +base.Class = (node, st, c) => { + if (node.id) c(node.id, st, "Pattern") + if (node.superClass) c(node.superClass, st, "Expression") + for (let i = 0; i < node.body.body.length; i++) + c(node.body.body[i], st) +} +base.MethodDefinition = base.Property = (node, st, c) => { + if (node.computed) c(node.key, st, "Expression") + c(node.value, st, "Expression") +} |