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Merged
merged 2 commits into from
Sep 5, 2014
Merged

Circular function expressions #610

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5fdc908
Deferred type checking of function expressions to support circular de…
ahejlsberg Sep 5, 2014
314a0d6
Accepting new baselines.
ahejlsberg Sep 5, 2014
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112 changes: 96 additions & 16 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -4524,25 +4524,26 @@ module ts {
}
}
}
checkSignatureDeclaration(node);
}
}
if (fullTypeCheck && !(links.flags & NodeCheckFlags.TypeChecked)) {
checkSignatureDeclaration(node);
return type;
}

function checkFunctionExpressionBody(node: FunctionExpression) {
if (node.type) {
checkIfNonVoidFunctionHasReturnExpressionsOrSingleThrowStatment(node, getTypeFromTypeNode(node.type));
}
if (node.body.kind === SyntaxKind.FunctionBlock) {
checkSourceElement(node.body);
}
else {
var exprType = checkExpression(node.body);
if (node.type) {
checkIfNonVoidFunctionHasReturnExpressionsOrSingleThrowStatment(node, getTypeFromTypeNode(node.type));
}
if (node.body.kind === SyntaxKind.FunctionBlock) {
checkSourceElement(node.body);
checkTypeAssignableTo(exprType, getTypeFromTypeNode(node.type), node.body, undefined, undefined);
}
else {
var exprType = checkExpression(node.body);
if (node.type) {
checkTypeAssignableTo(exprType, getTypeFromTypeNode(node.type), node.body, undefined, undefined);
}
}
links.flags |= NodeCheckFlags.TypeChecked;
checkFunctionExpressionBodies(node.body);
}
return type;
}

function checkArithmeticOperandType(operand: Node, type: Type, diagnostic: DiagnosticMessage): boolean {
Expand Down Expand Up @@ -6414,9 +6415,10 @@ module ts {
case SyntaxKind.FunctionDeclaration:
return checkFunctionDeclaration(<FunctionDeclaration>node);
case SyntaxKind.Block:
return checkBlock(<Block>node);
case SyntaxKind.FunctionBlock:
case SyntaxKind.ModuleBlock:
return checkBlock(<Block>node);
return checkBody(<Block>node);
case SyntaxKind.VariableStatement:
return checkVariableStatement(<VariableStatement>node);
case SyntaxKind.ExpressionStatement:
Expand Down Expand Up @@ -6463,13 +6465,91 @@ module ts {
}
}

// Function expression bodies are checked after all statements in the enclosing body. This is to ensure
// constructs like the following are permitted:
// var foo = function () {
// var s = foo();
// return "hello";
// }
// Here, performing a full type check of the body of the function expression whilst in the process of
// determining the type of foo would cause foo to be given type any because of the recursive reference.
// Delaying the type check of the body ensures foo has been assigned a type.
function checkFunctionExpressionBodies(node: Node): void {
switch (node.kind) {
case SyntaxKind.FunctionExpression:
case SyntaxKind.ArrowFunction:
forEach((<FunctionDeclaration>node).parameters, checkFunctionExpressionBodies);
checkFunctionExpressionBody(<FunctionExpression>node);
break;
case SyntaxKind.Method:
case SyntaxKind.Constructor:
case SyntaxKind.GetAccessor:
case SyntaxKind.SetAccessor:
case SyntaxKind.FunctionDeclaration:
forEach((<FunctionDeclaration>node).parameters, checkFunctionExpressionBodies);
break;
case SyntaxKind.WithStatement:
checkFunctionExpressionBodies((<WithStatement>node).expression);
break;
case SyntaxKind.Parameter:
case SyntaxKind.Property:
case SyntaxKind.ArrayLiteral:
case SyntaxKind.ObjectLiteral:
case SyntaxKind.PropertyAssignment:
case SyntaxKind.PropertyAccess:
case SyntaxKind.IndexedAccess:
case SyntaxKind.CallExpression:
case SyntaxKind.NewExpression:
case SyntaxKind.TypeAssertion:
case SyntaxKind.ParenExpression:
case SyntaxKind.PrefixOperator:
case SyntaxKind.PostfixOperator:
case SyntaxKind.BinaryExpression:
case SyntaxKind.ConditionalExpression:
case SyntaxKind.Block:
case SyntaxKind.FunctionBlock:
case SyntaxKind.ModuleBlock:
case SyntaxKind.VariableStatement:
case SyntaxKind.ExpressionStatement:
case SyntaxKind.IfStatement:
case SyntaxKind.DoStatement:
case SyntaxKind.WhileStatement:
case SyntaxKind.ForStatement:
case SyntaxKind.ForInStatement:
case SyntaxKind.ContinueStatement:
case SyntaxKind.BreakStatement:
case SyntaxKind.ReturnStatement:
case SyntaxKind.SwitchStatement:
case SyntaxKind.CaseClause:
case SyntaxKind.DefaultClause:
case SyntaxKind.LabelledStatement:
case SyntaxKind.ThrowStatement:
case SyntaxKind.TryStatement:
case SyntaxKind.TryBlock:
case SyntaxKind.CatchBlock:
case SyntaxKind.FinallyBlock:
case SyntaxKind.VariableDeclaration:
case SyntaxKind.ClassDeclaration:
case SyntaxKind.EnumDeclaration:
case SyntaxKind.EnumMember:
case SyntaxKind.SourceFile:
forEachChild(node, checkFunctionExpressionBodies);
break;
}
}

function checkBody(node: Block) {
checkBlock(node);
checkFunctionExpressionBodies(node);
}

// Fully type check a source file and collect the relevant diagnostics.
function checkSourceFile(node: SourceFile) {
var links = getNodeLinks(node);
if (!(links.flags & NodeCheckFlags.TypeChecked)) {
emitExtends = false;
potentialThisCollisions.length = 0;
forEach(node.statements, checkSourceElement);
checkBody(node);
if (isExternalModule(node)) {
var symbol = getExportAssignmentSymbol(node.symbol);
if (symbol && symbol.flags & SymbolFlags.Import) {
Expand Down
4 changes: 2 additions & 2 deletions tests/baselines/reference/declFileTypeofFunction.js
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Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,6 @@ declare function b1(): typeof b1;
declare function foo(): typeof foo;
declare var foo1: typeof foo;
declare var foo2: typeof foo;
declare var foo3: any;
declare var x: any;
declare var foo3: () => any;
declare var x: () => any;
declare function foo5(x: number): (x: number) => number;
8 changes: 4 additions & 4 deletions tests/baselines/reference/declFileTypeofFunction.types
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Original file line number Diff line number Diff line change
Expand Up @@ -54,18 +54,18 @@ var foo2 = foo;
>foo : () => typeof foo

var foo3 = function () {
>foo3 : any
>foo3 : () => any
>function () { return foo3;} : () => any

return foo3;
>foo3 : any
>foo3 : () => any
}
var x = () => {
>x : any
>x : () => any
>() => { return x;} : () => any

return x;
>x : any
>x : () => any
}

function foo5(x: number) {
Expand Down
6 changes: 1 addition & 5 deletions tests/baselines/reference/defaultArgsForwardReferencing.errors.txt
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
==== tests/cases/compiler/defaultArgsForwardReferencing.ts (12 errors) ====
==== tests/cases/compiler/defaultArgsForwardReferencing.ts (10 errors) ====
function left(a, b = a, c = b) {
a;
b;
Expand Down Expand Up @@ -37,11 +37,7 @@
}

function defaultArgFunction(a = function () { return b; }, b = 1) { }
~
!!! Initializer of parameter 'a' cannot reference identifier 'b' declared after it.
function defaultArgArrow(a = () => () => b, b = 3) { }
~
!!! Initializer of parameter 'a' cannot reference identifier 'b' declared after it.

class C {
constructor(a = b, b = 1) { }
Expand Down
6 changes: 3 additions & 3 deletions tests/baselines/reference/namedFunctionExpressionCall.types
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
=== tests/cases/compiler/namedFunctionExpressionCall.ts ===
var recurser = function foo() {
>recurser : any
>recurser : () => void
>function foo() { // using the local name foo(); // using the globally visible name recurser();} : () => void
>foo : () => void

Expand All @@ -11,8 +11,8 @@ var recurser = function foo() {

// using the globally visible name
recurser();
>recurser() : any
>recurser : any
>recurser() : void
>recurser : () => void

};

Expand Down
4 changes: 3 additions & 1 deletion tests/baselines/reference/parserStatementIsNotAMemberVariableDeclaration1.errors.txt
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@@ -1,4 +1,4 @@
==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/parserStatementIsNotAMemberVariableDeclaration1.ts (1 errors) ====
==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/parserStatementIsNotAMemberVariableDeclaration1.ts (2 errors) ====
return {
~~~~~~
!!! A 'return' statement can only be used within a function body.
Expand All @@ -7,6 +7,8 @@

// 'private' should not be considered a member variable here.
private[key] = value;
~~~~~~~
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@mhegazy mhegazy Sep 5, 2014

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this is interesting.. why was that missed before?
also the comment seems wrong.

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@ahejlsberg ahejlsberg Sep 5, 2014

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Previously this error wouldn't be reported because the expression in the return statement isn't type checked if the return statement occurs in a disallowed location. It's not worth the complexity to recompute whether we should skip the function expression body check phase, so the check always occurs.

!!! Cannot find name 'private'.
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@ahejlsberg ahejlsberg Sep 5, 2014

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Previously this error wouldn't be reported because the expression in the return statement isn't type checked if the return statement occurs in a disallowed location. It's not worth the complexity to recompute whether we should skip the function expression body check phase, so the check always occurs.


}

Expand Down
4 changes: 2 additions & 2 deletions tests/baselines/reference/recursiveInitializer.types
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Expand Up @@ -69,10 +69,10 @@ var b4 = (!b4) && b4; // expected boolean here. actually 'any'

// (x:string) => any
var f = (x: string) => f(x);
>f : any
>f : (x: string) => any
>(x: string) => f(x) : (x: string) => any
>x : string
>f(x) : any
>f : any
>f : (x: string) => any
>x : string

6 changes: 3 additions & 3 deletions tests/baselines/reference/underscoreTest1.types
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Expand Up @@ -601,7 +601,7 @@ $('#underscore_button').bind('click', buttonView.onClick);
>onClick : () => void

var fibonacci = _.memoize(function (n) {
>fibonacci : any
>fibonacci : (n: any) => any
>_.memoize(function (n) { return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);}) : (n: any) => any
>_.memoize : <T extends Function>(func: T, hashFunction?: Function) => T
>_ : Underscore.Static
Expand All @@ -616,11 +616,11 @@ var fibonacci = _.memoize(function (n) {
>n : any
>fibonacci(n - 1) + fibonacci(n - 2) : any
>fibonacci(n - 1) : any
>fibonacci : any
>fibonacci : (n: any) => any
>n - 1 : number
>n : any
>fibonacci(n - 2) : any
>fibonacci : any
>fibonacci : (n: any) => any
>n - 2 : number
>n : any

Expand Down