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/// <reference path="scanner.ts"/>
/// <reference path="utilities.ts"/>
module ts {
var nodeConstructors = new Array<new () => Node>(SyntaxKind.Count);
export function getNodeConstructor(kind: SyntaxKind): new () => Node {
return nodeConstructors[kind] || (nodeConstructors[kind] = objectAllocator.getNodeConstructor(kind));
}
export function createNode(kind: SyntaxKind): Node {
return new (getNodeConstructor(kind))();
}
function visitNode<T>(cbNode: (node: Node) => T, node: Node): T {
if (node) {
return cbNode(node);
}
}
function visitNodeArray<T>(cbNodes: (nodes: Node[]) => T, nodes: Node[]) {
if (nodes) {
return cbNodes(nodes);
}
}
function visitEachNode<T>(cbNode: (node: Node) => T, nodes: Node[]) {
if (nodes) {
for (var i = 0, len = nodes.length; i < len; i++) {
var result = cbNode(nodes[i]);
if (result) {
return result;
}
}
}
}
// Invokes a callback for each child of the given node. The 'cbNode' callback is invoked for all child nodes
// stored in properties. If a 'cbNodes' callback is specified, it is invoked for embedded arrays; otherwise,
// embedded arrays are flattened and the 'cbNode' callback is invoked for each element. If a callback returns
// a truthy value, iteration stops and that value is returned. Otherwise, undefined is returned.
export function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T {
if (!node) {
return;
}
// The visitXXX functions could be written as local functions that close over the cbNode and cbNodeArray
// callback parameters, but that causes a closure allocation for each invocation with noticeable effects
// on performance.
var visitNodes: (cb: (node: Node | Node[]) => T, nodes: Node[]) => T = cbNodeArray ? visitNodeArray : visitEachNode;
var cbNodes = cbNodeArray || cbNode;
switch (node.kind) {
case SyntaxKind.QualifiedName:
return visitNode(cbNode, (<QualifiedName>node).left) ||
visitNode(cbNode, (<QualifiedName>node).right);
case SyntaxKind.TypeParameter:
return visitNode(cbNode, (<TypeParameterDeclaration>node).name) ||
visitNode(cbNode, (<TypeParameterDeclaration>node).constraint) ||
visitNode(cbNode, (<TypeParameterDeclaration>node).expression);
case SyntaxKind.Parameter:
case SyntaxKind.PropertyDeclaration:
case SyntaxKind.PropertySignature:
case SyntaxKind.PropertyAssignment:
case SyntaxKind.ShorthandPropertyAssignment:
case SyntaxKind.VariableDeclaration:
case SyntaxKind.BindingElement:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).propertyName) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).dotDotDotToken) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).name) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).questionToken) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).type) ||
visitNode(cbNode, (<VariableLikeDeclaration>node).initializer);
case SyntaxKind.FunctionType:
case SyntaxKind.ConstructorType:
case SyntaxKind.CallSignature:
case SyntaxKind.ConstructSignature:
case SyntaxKind.IndexSignature:
return visitNodes(cbNodes, node.modifiers) ||
visitNodes(cbNodes, (<SignatureDeclaration>node).typeParameters) ||
visitNodes(cbNodes, (<SignatureDeclaration>node).parameters) ||
visitNode(cbNode, (<SignatureDeclaration>node).type);
case SyntaxKind.MethodDeclaration:
case SyntaxKind.MethodSignature:
case SyntaxKind.Constructor:
case SyntaxKind.GetAccessor:
case SyntaxKind.SetAccessor:
case SyntaxKind.FunctionExpression:
case SyntaxKind.FunctionDeclaration:
case SyntaxKind.ArrowFunction:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<FunctionLikeDeclaration>node).asteriskToken) ||
visitNode(cbNode, (<FunctionLikeDeclaration>node).name) ||
visitNode(cbNode, (<FunctionLikeDeclaration>node).questionToken) ||
visitNodes(cbNodes, (<FunctionLikeDeclaration>node).typeParameters) ||
visitNodes(cbNodes, (<FunctionLikeDeclaration>node).parameters) ||
visitNode(cbNode, (<FunctionLikeDeclaration>node).type) ||
visitNode(cbNode, (<FunctionLikeDeclaration>node).body);
case SyntaxKind.TypeReference:
return visitNode(cbNode, (<TypeReferenceNode>node).typeName) ||
visitNodes(cbNodes, (<TypeReferenceNode>node).typeArguments);
case SyntaxKind.TypeQuery:
return visitNode(cbNode, (<TypeQueryNode>node).exprName);
case SyntaxKind.TypeLiteral:
return visitNodes(cbNodes, (<TypeLiteralNode>node).members);
case SyntaxKind.ArrayType:
return visitNode(cbNode, (<ArrayTypeNode>node).elementType);
case SyntaxKind.TupleType:
return visitNodes(cbNodes, (<TupleTypeNode>node).elementTypes);
case SyntaxKind.UnionType:
return visitNodes(cbNodes, (<UnionTypeNode>node).types);
case SyntaxKind.ParenthesizedType:
return visitNode(cbNode, (<ParenthesizedTypeNode>node).type);
case SyntaxKind.ObjectBindingPattern:
case SyntaxKind.ArrayBindingPattern:
return visitNodes(cbNodes, (<BindingPattern>node).elements);
case SyntaxKind.ArrayLiteralExpression:
return visitNodes(cbNodes, (<ArrayLiteralExpression>node).elements);
case SyntaxKind.ObjectLiteralExpression:
return visitNodes(cbNodes, (<ObjectLiteralExpression>node).properties);
case SyntaxKind.PropertyAccessExpression:
return visitNode(cbNode, (<PropertyAccessExpression>node).expression) ||
visitNode(cbNode, (<PropertyAccessExpression>node).name);
case SyntaxKind.ElementAccessExpression:
return visitNode(cbNode, (<ElementAccessExpression>node).expression) ||
visitNode(cbNode, (<ElementAccessExpression>node).argumentExpression);
case SyntaxKind.CallExpression:
case SyntaxKind.NewExpression:
return visitNode(cbNode, (<CallExpression>node).expression) ||
visitNodes(cbNodes, (<CallExpression>node).typeArguments) ||
visitNodes(cbNodes, (<CallExpression>node).arguments);
case SyntaxKind.TaggedTemplateExpression:
return visitNode(cbNode, (<TaggedTemplateExpression>node).tag) ||
visitNode(cbNode, (<TaggedTemplateExpression>node).template);
case SyntaxKind.TypeAssertionExpression:
return visitNode(cbNode, (<TypeAssertion>node).type) ||
visitNode(cbNode, (<TypeAssertion>node).expression);
case SyntaxKind.ParenthesizedExpression:
return visitNode(cbNode, (<ParenthesizedExpression>node).expression);
case SyntaxKind.DeleteExpression:
return visitNode(cbNode, (<DeleteExpression>node).expression);
case SyntaxKind.TypeOfExpression:
return visitNode(cbNode, (<TypeOfExpression>node).expression);
case SyntaxKind.VoidExpression:
return visitNode(cbNode, (<VoidExpression>node).expression);
case SyntaxKind.PrefixUnaryExpression:
return visitNode(cbNode, (<PrefixUnaryExpression>node).operand);
case SyntaxKind.YieldExpression:
return visitNode(cbNode, (<YieldExpression>node).asteriskToken) ||
visitNode(cbNode, (<YieldExpression>node).expression);
case SyntaxKind.PostfixUnaryExpression:
return visitNode(cbNode, (<PostfixUnaryExpression>node).operand);
case SyntaxKind.BinaryExpression:
return visitNode(cbNode, (<BinaryExpression>node).left) ||
visitNode(cbNode, (<BinaryExpression>node).right);
case SyntaxKind.ConditionalExpression:
return visitNode(cbNode, (<ConditionalExpression>node).condition) ||
visitNode(cbNode, (<ConditionalExpression>node).whenTrue) ||
visitNode(cbNode, (<ConditionalExpression>node).whenFalse);
case SyntaxKind.SpreadElementExpression:
return visitNode(cbNode, (<SpreadElementExpression>node).expression);
case SyntaxKind.Block:
case SyntaxKind.ModuleBlock:
return visitNodes(cbNodes, (<Block>node).statements);
case SyntaxKind.SourceFile:
return visitNodes(cbNodes, (<SourceFile>node).statements) ||
visitNode(cbNode, (<SourceFile>node).endOfFileToken);
case SyntaxKind.VariableStatement:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<VariableStatement>node).declarationList);
case SyntaxKind.VariableDeclarationList:
return visitNodes(cbNodes, (<VariableDeclarationList>node).declarations);
case SyntaxKind.ExpressionStatement:
return visitNode(cbNode, (<ExpressionStatement>node).expression);
case SyntaxKind.IfStatement:
return visitNode(cbNode, (<IfStatement>node).expression) ||
visitNode(cbNode, (<IfStatement>node).thenStatement) ||
visitNode(cbNode, (<IfStatement>node).elseStatement);
case SyntaxKind.DoStatement:
return visitNode(cbNode, (<DoStatement>node).statement) ||
visitNode(cbNode, (<DoStatement>node).expression);
case SyntaxKind.WhileStatement:
return visitNode(cbNode, (<WhileStatement>node).expression) ||
visitNode(cbNode, (<WhileStatement>node).statement);
case SyntaxKind.ForStatement:
return visitNode(cbNode, (<ForStatement>node).initializer) ||
visitNode(cbNode, (<ForStatement>node).condition) ||
visitNode(cbNode, (<ForStatement>node).iterator) ||
visitNode(cbNode, (<ForStatement>node).statement);
case SyntaxKind.ForInStatement:
return visitNode(cbNode, (<ForInStatement>node).initializer) ||
visitNode(cbNode, (<ForInStatement>node).expression) ||
visitNode(cbNode, (<ForInStatement>node).statement);
case SyntaxKind.ContinueStatement:
case SyntaxKind.BreakStatement:
return visitNode(cbNode, (<BreakOrContinueStatement>node).label);
case SyntaxKind.ReturnStatement:
return visitNode(cbNode, (<ReturnStatement>node).expression);
case SyntaxKind.WithStatement:
return visitNode(cbNode, (<WithStatement>node).expression) ||
visitNode(cbNode, (<WithStatement>node).statement);
case SyntaxKind.SwitchStatement:
return visitNode(cbNode, (<SwitchStatement>node).expression) ||
visitNodes(cbNodes, (<SwitchStatement>node).clauses);
case SyntaxKind.CaseClause:
return visitNode(cbNode, (<CaseClause>node).expression) ||
visitNodes(cbNodes, (<CaseClause>node).statements);
case SyntaxKind.DefaultClause:
return visitNodes(cbNodes, (<DefaultClause>node).statements);
case SyntaxKind.LabeledStatement:
return visitNode(cbNode, (<LabeledStatement>node).label) ||
visitNode(cbNode, (<LabeledStatement>node).statement);
case SyntaxKind.ThrowStatement:
return visitNode(cbNode, (<ThrowStatement>node).expression);
case SyntaxKind.TryStatement:
return visitNode(cbNode, (<TryStatement>node).tryBlock) ||
visitNode(cbNode, (<TryStatement>node).catchClause) ||
visitNode(cbNode, (<TryStatement>node).finallyBlock);
case SyntaxKind.CatchClause:
return visitNode(cbNode, (<CatchClause>node).name) ||
visitNode(cbNode, (<CatchClause>node).type) ||
visitNode(cbNode, (<CatchClause>node).block);
case SyntaxKind.ClassDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<ClassDeclaration>node).name) ||
visitNodes(cbNodes, (<ClassDeclaration>node).typeParameters) ||
visitNodes(cbNodes, (<ClassDeclaration>node).heritageClauses) ||
visitNodes(cbNodes, (<ClassDeclaration>node).members);
case SyntaxKind.InterfaceDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<InterfaceDeclaration>node).name) ||
visitNodes(cbNodes, (<InterfaceDeclaration>node).typeParameters) ||
visitNodes(cbNodes, (<ClassDeclaration>node).heritageClauses) ||
visitNodes(cbNodes, (<InterfaceDeclaration>node).members);
case SyntaxKind.TypeAliasDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<TypeAliasDeclaration>node).name) ||
visitNode(cbNode, (<TypeAliasDeclaration>node).type);
case SyntaxKind.EnumDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<EnumDeclaration>node).name) ||
visitNodes(cbNodes, (<EnumDeclaration>node).members);
case SyntaxKind.EnumMember:
return visitNode(cbNode, (<EnumMember>node).name) ||
visitNode(cbNode, (<EnumMember>node).initializer);
case SyntaxKind.ModuleDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<ModuleDeclaration>node).name) ||
visitNode(cbNode, (<ModuleDeclaration>node).body);
case SyntaxKind.ImportDeclaration:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<ImportDeclaration>node).name) ||
visitNode(cbNode, (<ImportDeclaration>node).moduleReference);
case SyntaxKind.ExportAssignment:
return visitNodes(cbNodes, node.modifiers) ||
visitNode(cbNode, (<ExportAssignment>node).exportName);
case SyntaxKind.TemplateExpression:
return visitNode(cbNode, (<TemplateExpression>node).head) || visitNodes(cbNodes, (<TemplateExpression>node).templateSpans);
case SyntaxKind.TemplateSpan:
return visitNode(cbNode, (<TemplateSpan>node).expression) || visitNode(cbNode, (<TemplateSpan>node).literal);
case SyntaxKind.ComputedPropertyName:
return visitNode(cbNode, (<ComputedPropertyName>node).expression);
case SyntaxKind.HeritageClause:
return visitNodes(cbNodes, (<HeritageClause>node).types);
case SyntaxKind.ExternalModuleReference:
return visitNode(cbNode, (<ExternalModuleReference>node).expression);
}
}
const enum ParsingContext {
SourceElements, // Elements in source file
ModuleElements, // Elements in module declaration
BlockStatements, // Statements in block
SwitchClauses, // Clauses in switch statement
SwitchClauseStatements, // Statements in switch clause
TypeMembers, // Members in interface or type literal
ClassMembers, // Members in class declaration
EnumMembers, // Members in enum declaration
TypeReferences, // Type references in extends or implements clause
VariableDeclarations, // Variable declarations in variable statement
ObjectBindingElements, // Binding elements in object binding list
ArrayBindingElements, // Binding elements in array binding list
ArgumentExpressions, // Expressions in argument list
ObjectLiteralMembers, // Members in object literal
ArrayLiteralMembers, // Members in array literal
Parameters, // Parameters in parameter list
TypeParameters, // Type parameters in type parameter list
TypeArguments, // Type arguments in type argument list
TupleElementTypes, // Element types in tuple element type list
HeritageClauses, // Heritage clauses for a class or interface declaration.
Count // Number of parsing contexts
}
const enum Tristate {
False,
True,
Unknown
}
function parsingContextErrors(context: ParsingContext): DiagnosticMessage {
switch (context) {
case ParsingContext.SourceElements: return Diagnostics.Declaration_or_statement_expected;
case ParsingContext.ModuleElements: return Diagnostics.Declaration_or_statement_expected;
case ParsingContext.BlockStatements: return Diagnostics.Statement_expected;
case ParsingContext.SwitchClauses: return Diagnostics.case_or_default_expected;
case ParsingContext.SwitchClauseStatements: return Diagnostics.Statement_expected;
case ParsingContext.TypeMembers: return Diagnostics.Property_or_signature_expected;
case ParsingContext.ClassMembers: return Diagnostics.Unexpected_token_A_constructor_method_accessor_or_property_was_expected;
case ParsingContext.EnumMembers: return Diagnostics.Enum_member_expected;
case ParsingContext.TypeReferences: return Diagnostics.Type_reference_expected;
case ParsingContext.VariableDeclarations: return Diagnostics.Variable_declaration_expected;
case ParsingContext.ObjectBindingElements: return Diagnostics.Property_destructuring_pattern_expected;
case ParsingContext.ArrayBindingElements: return Diagnostics.Array_element_destructuring_pattern_expected;
case ParsingContext.ArgumentExpressions: return Diagnostics.Argument_expression_expected;
case ParsingContext.ObjectLiteralMembers: return Diagnostics.Property_assignment_expected;
case ParsingContext.ArrayLiteralMembers: return Diagnostics.Expression_or_comma_expected;
case ParsingContext.Parameters: return Diagnostics.Parameter_declaration_expected;
case ParsingContext.TypeParameters: return Diagnostics.Type_parameter_declaration_expected;
case ParsingContext.TypeArguments: return Diagnostics.Type_argument_expected;
case ParsingContext.TupleElementTypes: return Diagnostics.Type_expected;
case ParsingContext.HeritageClauses: return Diagnostics.Unexpected_token_expected;
}
};
export function modifierToFlag(token: SyntaxKind): NodeFlags {
switch (token) {
case SyntaxKind.StaticKeyword: return NodeFlags.Static;
case SyntaxKind.PublicKeyword: return NodeFlags.Public;
case SyntaxKind.ProtectedKeyword: return NodeFlags.Protected;
case SyntaxKind.PrivateKeyword: return NodeFlags.Private;
case SyntaxKind.ExportKeyword: return NodeFlags.Export;
case SyntaxKind.DeclareKeyword: return NodeFlags.Ambient;
case SyntaxKind.ConstKeyword: return NodeFlags.Const;
}
return 0;
}
function fixupParentReferences(sourceFile: SourceFile) {
// normally parent references are set during binding.
// however here SourceFile data is used only for syntactic features so running the whole binding process is an overhead.
// walk over the nodes and set parent references
var parent: Node = sourceFile;
function walk(n: Node): void {
// walk down setting parents that differ from the parent we think it should be. This
// allows us to quickly bail out of setting parents for subtrees during incremental
// parsing
if (n.parent !== parent) {
n.parent = parent;
var saveParent = parent;
parent = n;
forEachChild(n, walk);
parent = saveParent;
}
}
forEachChild(sourceFile, walk);
}
export function isEvalOrArgumentsIdentifier(node: Node): boolean {
return node.kind === SyntaxKind.Identifier &&
((<Identifier>node).text === "eval" || (<Identifier>node).text === "arguments");
}
/// Should be called only on prologue directives (isPrologueDirective(node) should be true)
function isUseStrictPrologueDirective(sourceFile: SourceFile, node: Node): boolean {
Debug.assert(isPrologueDirective(node));
var nodeText = getSourceTextOfNodeFromSourceFile(sourceFile,(<ExpressionStatement>node).expression);
// Note: the node text must be exactly "use strict" or 'use strict'. It is not ok for the
// string to contain unicode escapes (as per ES5).
return nodeText === '"use strict"' || nodeText === "'use strict'";
}
interface IncrementalElement extends TextRange {
parent?: Node;
intersectsChange: boolean
length?: number;
_children: Node[];
}
interface IncrementalNode extends Node, IncrementalElement {
}
interface IncrementalNodeArray extends NodeArray<IncrementalNode>, IncrementalElement {
length: number
}
// Allows finding nodes in the source file at a certain position in an efficient manner.
// The implementation takes advantage of the calling pattern it knows the parser will
// make in order to optimize finding nodes as quickly as possible.
interface SyntaxCursor {
currentNode(position: number): IncrementalNode;
}
const enum InvalidPosition {
Value = -1
}
function createSyntaxCursor(sourceFile: SourceFile): SyntaxCursor {
var currentArray: NodeArray<Node> = sourceFile.statements;
var currentArrayIndex = 0;
Debug.assert(currentArrayIndex < currentArray.length);
var current = currentArray[currentArrayIndex];
var lastQueriedPosition = InvalidPosition.Value;
return {
currentNode(position: number) {
// Only compute the current node if the position is different than the last time
// we were asked. The parser commonly asks for the node at the same position
// twice. Once to know if can read an appropriate list element at a certain point,
// and then to actually read and consume the node.
if (position !== lastQueriedPosition) {
// Much of the time the parser will need the very next node in the array that
// we just returned a node from.So just simply check for that case and move
// forward in the array instead of searching for the node again.
if (current && current.end === position && currentArrayIndex < currentArray.length) {
currentArrayIndex++;
current = currentArray[currentArrayIndex];
}
// If we don't have a node, or the node we have isn't in the right position,
// then try to find a viable node at the position requested.
if (!current || current.pos !== position) {
findHighestListElementThatStartsAtPosition(position);
}
}
// Cache this query so that we don't do any extra work if the parser calls back
// into us. Note: this is very common as the parser will make pairs of calls like
// 'isListElement -> parseListElement'. If we were unable to find a node when
// called with 'isListElement', we don't want to redo the work when parseListElement
// is called immediately after.
lastQueriedPosition = position;
// Either we don'd have a node, or we have a node at the position being asked for.
Debug.assert(!current || current.pos === position);
return <IncrementalNode>current;
}
};
// Finds the highest element in the tree we can find that starts at the provided position.
// The element must be a direct child of some node list in the tree. This way after we
// return it, we can easily return its next sibling in the list.
function findHighestListElementThatStartsAtPosition(position: number) {
// Clear out any cached state about the last node we found.
currentArray = undefined;
currentArrayIndex = InvalidPosition.Value;
current = undefined;
// Recurse into the source file to find the highest node at this position.
forEachChild(sourceFile, visitNode, visitArray);
function visitNode(node: Node) {
if (position >= node.pos && position < node.end) {
// Position was within this node. Keep searching deeper to find the node.
forEachChild(node, visitNode, visitArray);
// don't procede any futher in the search.
return true;
}
// position wasn't in this node, have to keep searching.
return false;
}
function visitArray(array: NodeArray<Node>) {
if (position >= array.pos && position < array.end) {
// position was in this array. Search through this array to see if we find a
// viable element.
for (var i = 0, n = array.length; i < n; i++) {
var child = array[i];
if (child) {
if (child.pos === position) {
// Found the right node. We're done.
currentArray = array;
currentArrayIndex = i;
current = child;
return true;
}
else {
if (child.pos < position && position < child.end) {
// Position in somewhere within this child. Search in it and
// stop searching in this array.
forEachChild(child, visitNode, visitArray);
return true;
}
}
}
}
}
// position wasn't in this array, have to keep searching.
return false;
}
}
}
export function createSourceFile(filename: string, sourceText: string, languageVersion: ScriptTarget, setParentNodes = false): SourceFile {
var parsingContext: ParsingContext;
var identifiers: Map<string>;
var identifierCount = 0;
var nodeCount = 0;
var lineStarts: number[];
var syntacticDiagnostics: Diagnostic[];
var scanner: Scanner;
var token: SyntaxKind;
var syntaxCursor: SyntaxCursor;
// Flags that dictate what parsing context we're in. For example:
// Whether or not we are in strict parsing mode. All that changes in strict parsing mode is
// that some tokens that would be considered identifiers may be considered keywords.
//
// When adding more parser context flags, consider which is the more common case that the
// flag will be in. This should be hte 'false' state for that flag. The reason for this is
// that we don't store data in our nodes unless the value is in the *non-default* state. So,
// for example, more often than code 'allows-in' (or doesn't 'disallow-in'). We opt for
// 'disallow-in' set to 'false'. Otherwise, if we had 'allowsIn' set to 'true', then almost
// all nodes would need extra state on them to store this info.
//
// Note: 'allowIn' and 'allowYield' track 1:1 with the [in] and [yield] concepts in the ES6
// grammar specification.
//
// An important thing about these context concepts. By default they are effectively inherited
// while parsing through every grammar production. i.e. if you don't change them, then when
// you parse a sub-production, it will have the same context values as hte parent production.
// This is great most of the time. After all, consider all the 'expression' grammar productions
// and how nearly all of them pass along the 'in' and 'yield' context values:
//
// EqualityExpression[In, Yield] :
// RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] == RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] != RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] === RelationalExpression[?In, ?Yield]
// EqualityExpression[?In, ?Yield] !== RelationalExpression[?In, ?Yield]
//
// Where you have to be careful is then understanding what the points are in the grammar
// where the values are *not* passed along. For example:
//
// SingleNameBinding[Yield,GeneratorParameter]
// [+GeneratorParameter]BindingIdentifier[Yield] Initializer[In]opt
// [~GeneratorParameter]BindingIdentifier[?Yield]Initializer[In, ?Yield]opt
//
// Here this is saying that if the GeneratorParameter context flag is set, that we should
// explicitly set the 'yield' context flag to false before calling into the BindingIdentifier
// and we should explicitly unset the 'yield' context flag before calling into the Initializer.
// production. Conversely, if the GeneratorParameter context flag is not set, then we
// should leave the 'yield' context flag alone.
//
// Getting this all correct is tricky and requires careful reading of the grammar to
// understand when these values should be changed versus when they should be inherited.
//
// Note: it should not be necessary to save/restore these flags during speculative/lookahead
// parsing. These context flags are naturally stored and restored through normal recursive
// descent parsing and unwinding.
var contextFlags: ParserContextFlags;
// Whether or not we've had a parse error since creating the last AST node. If we have
// encountered an error, it will be stored on the next AST node we create. Parse errors
// can be broken down into three categories:
//
// 1) An error that occurred during scanning. For example, an unterminated literal, or a
// character that was completely not understood.
//
// 2) A token was expected, but was not present. This type of error is commonly produced
// by the 'parseExpected' function.
//
// 3) A token was present that no parsing function was able to consume. This type of error
// only occurs in the 'abortParsingListOrMoveToNextToken' function when the parser
// decides to skip the token.
//
// In all of these cases, we want to mark the next node as having had an error before it.
// With this mark, we can know in incremental settings if this node can be reused, or if
// we have to reparse it. If we don't keep this information around, we may just reuse the
// node. in that event we would then not produce the same errors as we did before, causing
// significant confusion problems.
//
// Note: it is necessary that this value be saved/restored during speculative/lookahead
// parsing. During lookahead parsing, we will often create a node. That node will have
// this value attached, and then this value will be set back to 'false'. If we decide to
// rewind, we must get back to the same value we had prior to the lookahead.
//
// Note: any errors at the end of the file that do not precede a regular node, should get
// attached to the EOF token.
var parseErrorBeforeNextFinishedNode: boolean;
var sourceFile: SourceFile;
return parseSourceFile(sourceText, setParentNodes);
function parseSourceFile(text: string, setParentNodes: boolean): SourceFile {
// Set our initial state before parsing.
sourceText = text;
parsingContext = 0;
identifiers = {};
lineStarts = undefined;
syntacticDiagnostics = undefined;
contextFlags = 0;
parseErrorBeforeNextFinishedNode = false;
sourceFile = <SourceFile>createNode(SyntaxKind.SourceFile, 0);
sourceFile.referenceDiagnostics = [];
sourceFile.parseDiagnostics = [];
sourceFile.semanticDiagnostics = [];
// Create and prime the scanner before parsing the source elements.
scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceText, scanError);
token = nextToken();
sourceFile.flags = fileExtensionIs(filename, ".d.ts") ? NodeFlags.DeclarationFile : 0;
sourceFile.end = sourceText.length;
sourceFile.filename = normalizePath(filename);
sourceFile.text = sourceText;
sourceFile.getLineAndCharacterFromPosition = getLineAndCharacterFromSourcePosition;
sourceFile.getPositionFromLineAndCharacter = getPositionFromSourceLineAndCharacter;
sourceFile.getLineStarts = getLineStarts;
sourceFile.getSyntacticDiagnostics = getSyntacticDiagnostics;
sourceFile.update = update;
processReferenceComments(sourceFile);
sourceFile.statements = parseList(ParsingContext.SourceElements, /*checkForStrictMode*/ true, parseSourceElement);
Debug.assert(token === SyntaxKind.EndOfFileToken);
sourceFile.endOfFileToken = parseTokenNode();
setExternalModuleIndicator(sourceFile);
sourceFile.nodeCount = nodeCount;
sourceFile.identifierCount = identifierCount;
sourceFile.languageVersion = languageVersion;
sourceFile.identifiers = identifiers;
if (setParentNodes) {
fixupParentReferences(sourceFile);
}
return sourceFile;
}
function update(newText: string, textChangeRange: TextChangeRange) {
if (textChangeRangeIsUnchanged(textChangeRange)) {
// if the text didn't change, then we can just return our current source file as-is.
return sourceFile;
}
if (sourceFile.statements.length === 0) {
// If we don't have any statements in the current source file, then there's no real
// way to incrementally parse. So just do a full parse instead.
return parseSourceFile(newText, /*setNodeParents*/ true);
}
syntaxCursor = createSyntaxCursor(sourceFile);
// Make the actual change larger so that we know to reparse anything whose lookahead
// might have intersected the change.
var changeRange = extendToAffectedRange(textChangeRange);
// The is the amount the nodes after the edit range need to be adjusted. It can be
// positive (if the edit added characters), negative (if the edit deleted characters)
// or zero (if this was a pure overwrite with nothing added/removed).
var delta = textChangeRangeNewSpan(changeRange).length - changeRange.span.length;
// If we added or removed characters during the edit, then we need to go and adjust all
// the nodes after the edit. Those nodes may move forward down (if we inserted chars)
// or they may move backward (if we deleted chars).
//
// Doing this helps us out in two ways. First, it means that any nodes/tokens we want
// to reuse are already at the appropriate position in the new text. That way when we
// reuse them, we don't have to figure out if they need to be adjusted. Second, it makes
// it very easy to determine if we can reuse a node. If the node's position is at where
// we are in the text, then we can reuse it. Otherwise we can't. If hte node's position
// is ahead of us, then we'll need to rescan tokens. If the node's position is behind
// us, then we'll need to skip it or crumble it as appropriate
//
// We will also adjust the positions of nodes that intersect the change range as well.
// By doing this, we ensure that all the positions in the old tree are consistent, not
// just the positions of nodes entirely before/after the change range. By being
// consistent, we can then easily map from positions to nodes in the old tree easily.
//
// Also, mark any syntax elements that intersect the changed span. We know, up front,
// that we cannot reuse these elements.
updateTokenPositionsAndMarkElements(<IncrementalNode><Node>sourceFile,
changeRange.span.start, textSpanEnd(changeRange.span), textSpanEnd(textChangeRangeNewSpan(changeRange)), delta);
// Now that we've set up our internal incremental state just proceed and parse the
// source file in the normal fashion. When possible the parser will retrieve and
// reuse nodes from the old tree.
//
// Note: passing in 'true' for setNodeParents is very important. When incrementally
// parsing, we will be reusing nodes from the old tree, and placing it into new
// parents. If we don't set the parents now, we'll end up with an observably
// inconsistent tree. Setting the parents on the new tree should be very fast. We
// will immediately bail out of walking any subtrees when we can see that their parents
// are already correct.
var result = parseSourceFile(newText, /*setNodeParents*/ true);
// Clear out the syntax cursor so it doesn't keep anything alive longer than it should.
syntaxCursor = undefined;
return result;
}
function updateTokenPositionsAndMarkElements(node: IncrementalNode, changeStart: number, changeRangeOldEnd: number, changeRangeNewEnd: number, delta: number): void {
visitNode(node);
function visitNode(child: IncrementalNode) {
if (child.pos > changeRangeOldEnd) {
// Node is entirely past the change range. We need to move both its pos and
// end, forward or backward appropriately.
moveElementEntirelyPastChangeRange(child, delta);
return;
}
// Check if the element intersects the change range. If it does, then it is not
// reusable. Also, we'll need to recurse to see what constituent portions we may
// be able to use.
var fullEnd = child.end;
if (fullEnd >= changeStart) {
child.intersectsChange = true;
// Adjust the pos or end (or both) of the intersecting element accordingly.
adjustIntersectingElement(child, changeStart, changeRangeOldEnd, changeRangeNewEnd, delta);
forEachChild(child, visitNode, visitArray);
return;
}
// Otherwise, the node is entirely before the change range. No need to do anything with it.
}
function visitArray(array: IncrementalNodeArray) {
if (array.pos > changeRangeOldEnd) {
// Array is entirely after the change range. We need to move it, and move any of
// its children.
moveElementEntirelyPastChangeRange(array, delta);
}
else {
// Check if the element intersects the change range. If it does, then it is not
// reusable. Also, we'll need to recurse to see what constituent portions we may
// be able to use.
var fullEnd = array.end;
if (fullEnd >= changeStart) {
array.intersectsChange = true;
// Adjust the pos or end (or both) of the intersecting array accordingly.
adjustIntersectingElement(array, changeStart, changeRangeOldEnd, changeRangeNewEnd, delta);
for (var i = 0, n = array.length; i < n; i++) {
visitNode(array[i]);
}
}
// else {
// Otherwise, the array is entirely before the change range. No need to do anything with it.
// }
}
}
}
function adjustIntersectingElement(element: IncrementalElement, changeStart: number, changeRangeOldEnd: number, changeRangeNewEnd: number, delta: number) {
Debug.assert(element.end >= changeStart, "Adjusting an element that was entirely before the change range");
Debug.assert(element.pos <= changeRangeOldEnd, "Adjusting an element that was entirely after the change range");
// We have an element that intersects the change range in some way. It may have its
// start, or its end (or both) in the changed range. We want to adjust any part
// that intersects such that the final tree is in a consistent state. i.e. all
// chlidren have spans within the span of their parent, and all siblings are ordered
// properly.
// We may need to update both the 'pos' and the 'end' of the element.
// If the 'pos' is before the start of the change, then we don't need to touch it.
// If it isn't, then the 'pos' must be inside the change. How we update it will
// depend if delta is positive or negative. If delta is positive then we have
// something like:
//
// -------------------AAA-----------------
// -------------------BBBCCCCCCC-----------------
//
// In this case, we consider any node that started in the change range to still be
// starting at the same position.
//
// however, if the delta is negative, then we instead have something like this:
//
// -------------------XXXYYYYYYY-----------------
// -------------------ZZZ-----------------
//
// In this case, any element that started in the 'X' range will keep its position.
// However any element htat started after that will have their pos adjusted to be
// at the end of the new range. i.e. any node that started in the 'Y' range will
// be adjusted to have their start at the end of the 'Z' range.
//
// The element will keep its position if possible. Or Move backward to the new-end
// if it's in the 'Y' range.
element.pos = Math.min(element.pos, changeRangeNewEnd);
// If the 'end' is after the change range, then we always adjust it by the delta
// amount. However, if the end is in the change range, then how we adjust it
// will depend on if delta is positive or negative. If delta is positive then we
// have something like:
//
// -------------------AAA-----------------
// -------------------BBBCCCCCCC-----------------
//
// In this case, we consider any node that ended inside the change range to keep its
// end position.
//
// however, if the delta is negative, then we instead have something like this:
//
// -------------------XXXYYYYYYY-----------------
// -------------------ZZZ-----------------
//
// In this case, any element that ended in the 'X' range will keep its position.
// However any element htat ended after that will have their pos adjusted to be
// at the end of the new range. i.e. any node that ended in the 'Y' range will
// be adjusted to have their end at the end of the 'Z' range.
if (element.end >= changeRangeOldEnd) {
// Element ends after the change range. Always adjust the end pos.
element.end += delta;
}
else {
// Element ends in the change range. The element will keep its position if
// possible. Or Move backward to the new-end if it's in the 'Y' range.
element.end = Math.min(element.end, changeRangeNewEnd);
}
Debug.assert(element.pos <= element.end);
if (element.parent) {
Debug.assert(element.pos >= element.parent.pos);
Debug.assert(element.end <= element.parent.end);
}
}
function moveElementEntirelyPastChangeRange(element: IncrementalElement, delta: number) {
if (element.length) {
visitArray(<IncrementalNodeArray>element);
}
else {
visitNode(<IncrementalNode>element);
}
function visitNode(node: IncrementalNode) {
// Ditch any existing LS children we may have created. This way we can avoid
// moving them forward.
node._children = undefined;
node.pos += delta;
node.end += delta;
forEachChild(node, visitNode, visitArray);
}
function visitArray(array: IncrementalNodeArray) {
array.pos += delta;
array.end += delta;
for (var i = 0, n = array.length; i < n; i++) {
visitNode(array[i]);
}
}
}
function extendToAffectedRange(changeRange: TextChangeRange): TextChangeRange {
// Consider the following code:
// void foo() { /; }
//
// If the text changes with an insertion of / just before the semicolon then we end up with:
// void foo() { //; }
//
// If we were to just use the changeRange a is, then we would not rescan the { token
// (as it does not intersect the actual original change range). Because an edit may
// change the token touching it, we actually need to look back *at least* one token so
// that the prior token sees that change.
var maxLookahead = 1;
var start = changeRange.span.start;
// the first iteration aligns us with the change start. subsequent iteration move us to
// the left by maxLookahead tokens. We only need to do this as long as we're not at the
// start of the tree.
for (var i = 0; start > 0 && i <= maxLookahead; i++) {
var nearestNode = findNearestNodeStartingBeforeOrAtPosition(start);
var position = nearestNode.pos;
start = Math.max(0, position - 1);
}
var finalSpan = createTextSpanFromBounds(start, textSpanEnd(changeRange.span));
var finalLength = changeRange.newLength + (changeRange.span.start - start);
return createTextChangeRange(finalSpan, finalLength);
}
function findNearestNodeStartingBeforeOrAtPosition(position: number): Node {
var bestResult: Node = sourceFile;
var lastNodeEntirelyBeforePosition: Node;
forEachChild(sourceFile, visit);
if (lastNodeEntirelyBeforePosition) {
var lastChildOfLastEntireNodeBeforePosition = getLastChild(lastNodeEntirelyBeforePosition);
if (lastChildOfLastEntireNodeBeforePosition.pos > bestResult.pos) {
bestResult = lastChildOfLastEntireNodeBeforePosition;
}
}
return bestResult;
function getLastChild(node: Node): Node {
while (true) {
var lastChild = getLastChildWorker(node);
if (lastChild) {
node = lastChild;
}
else {
return node;
}
}
}
function getLastChildWorker(node: Node): Node {
var last:Node = undefined;
forEachChild(node, child => {
if (nodeIsPresent(child)) {
last = child;
}
});
return last;
}
function visit(child: Node) {
if (nodeIsMissing(child)) {
// Missing nodes are effectively invisible to us. We never even consider them
// When trying to find the nearest node before us.
return;
}
// If the child intersects this position, then this node is currently the nearest
// node that starts before the position.
if (child.pos <= position) {
if (child.pos >= bestResult.pos) {
// This node starts before the position, and is closer to the position than
// the previous best node we found. It is now the new best node.
bestResult = child;
}
// Now, the node may overlap the position, or it may end entirely before the
// position. If it overlaps with the position, then either it, or one of its
// children must be the nearest node before the position. So we can just
// recurse into this child to see if we can find something better.
if (position < child.end) {
// The nearest node is either this child, or one of the children inside
// of it. We've already marked this child as the best so far. Recurse
// in case one of the children is better.
forEachChild(child, visit);
// Once we look at the children of this node, then there's no need to
// continue any further.
return true;
}
else {
Debug.assert(child.end <= position);
// The child ends entirely before this position. Say you have the following
// (where $ is the position)
//
// <complex expr 1> ? <complex expr 2> $ : <...> <...>
//
// We would want to find the nearest preceding node in "complex expr 2".
// To support that, we keep track of this node, and once we're done searching
// for a best node, we recurse down this node to see if we can find a good
// result in it.
//
// This approach allows us to quickly skip over nodes that are entirely
// before the position, while still allowing us to find any nodes in the
// last one that might be what we want.
lastNodeEntirelyBeforePosition = child;
}
}
else {
Debug.assert(child.pos > position);
// We're now at a node that is entirely past the position we're searching for.
// This node (and all following nodes) could never contribute to the result,
// so just skip them by returning 'true' here.
return true;
}
}
}
function setContextFlag(val: Boolean, flag: ParserContextFlags) {
if (val) {
contextFlags |= flag;
}
else {
contextFlags &= ~flag;
}
}
function setStrictModeContext(val: boolean) {
setContextFlag(val, ParserContextFlags.StrictMode);
}
function setDisallowInContext(val: boolean) {
setContextFlag(val, ParserContextFlags.DisallowIn);