[Flow] Function predicate declaration (#103)

* [Flow] Function predicate declaration

The accepted syntax for function declarations is extended to allow
the following predicate declaration:

  FunctionReturnType :=
    Type
    Predicate
    Type Predicate

  Predicate :=
    %checks
    %checks ( ConditionalExpression )

* [Flow] Minor tweaks and more examples to function predicates

* [Flow] Clean-up and better message for function predicates

* [Flow] Adding abstract function predicate example

* [Flow] Rearranging the `predicate` field to ease babel generator.
This commit is contained in:
Panagiotis Vekris 2017-02-10 05:55:13 -08:00 committed by Daniel Tschinder
parent 898c4a7623
commit e049ec3456
13 changed files with 1415 additions and 4 deletions

View File

@ -28,6 +28,45 @@ pp.flowParseTypeInitialiser = function (tok) {
return type;
};
pp.flowParsePredicate = function() {
const node = this.startNode();
const moduloLoc = this.state.startLoc;
const moduloPos = this.state.start;
this.expect(tt.modulo);
const checksLoc = this.state.startLoc;
this.expectContextual("checks");
// Force '%' and 'checks' to be adjacent
if (moduloLoc.line !== checksLoc.line || moduloLoc.column !== checksLoc.column - 1) {
this.raise(moduloPos, "Spaces between ´%´ and ´checks´ are not allowed here.");
}
if (this.eat(tt.parenL)) {
node.expression = this.parseExpression();
this.expect(tt.parenR);
return this.finishNode(node, "DeclaredPredicate");
} else {
return this.finishNode(node, "InferredPredicate");
}
};
pp.flowParseTypeAndPredicateInitialiser = function () {
const oldInType = this.state.inType;
this.state.inType = true;
this.expect(tt.colon);
let type = null;
let predicate = null;
if (this.match(tt.modulo)) {
this.state.inType = oldInType;
predicate = this.flowParsePredicate();
} else {
type = this.flowParseType();
this.state.inType = oldInType;
if (this.match(tt.modulo)) {
predicate = this.flowParsePredicate();
}
}
return [type, predicate];
};
pp.flowParseDeclareClass = function (node) {
this.next();
this.flowParseInterfaceish(node, true);
@ -53,9 +92,10 @@ pp.flowParseDeclareFunction = function (node) {
typeNode.params = tmp.params;
typeNode.rest = tmp.rest;
this.expect(tt.parenR);
typeNode.returnType = this.flowParseTypeInitialiser();
let predicate = null;
[typeNode.returnType, predicate] = this.flowParseTypeAndPredicateInitialiser();
typeContainer.typeAnnotation = this.finishNode(typeNode, "FunctionTypeAnnotation");
typeContainer.predicate = predicate;
id.typeAnnotation = this.finishNode(typeContainer, "TypeAnnotation");
this.finishNode(id, id.type);
@ -789,6 +829,12 @@ pp.flowParseTypeAnnotation = function () {
return this.finishNode(node, "TypeAnnotation");
};
pp.flowParseTypeAndPredicateAnnotation = function () {
const node = this.startNode();
[node.typeAnnotation, node.predicate] = this.flowParseTypeAndPredicateInitialiser();
return this.finishNode(node, "TypeAnnotation");
};
pp.flowParseTypeAnnotatableIdentifier = function () {
const ident = this.flowParseRestrictedIdentifier();
if (this.match(tt.colon)) {
@ -829,7 +875,7 @@ export default function (instance) {
if (this.match(tt.colon) && !allowExpression) {
// if allowExpression is true then we're parsing an arrow function and if
// there's a return type then it's been handled elsewhere
node.returnType = this.flowParseTypeAnnotation();
node.returnType = this.flowParseTypeAndPredicateAnnotation();
}
return inner.call(this, node, allowExpression);
@ -1378,7 +1424,7 @@ export default function (instance) {
try {
const oldNoAnonFunctionType = this.state.noAnonFunctionType;
this.state.noAnonFunctionType = true;
const returnType = this.flowParseTypeAnnotation();
const returnType = this.flowParseTypeAndPredicateAnnotation();
this.state.noAnonFunctionType = oldNoAnonFunctionType;
if (this.canInsertSemicolon()) this.unexpected();

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@ -0,0 +1 @@
declare function foo(x: mixed): boolean %checks(x !== null);

View File

@ -0,0 +1,226 @@
{
"type": "File",
"start": 0,
"end": 60,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 60
}
},
"program": {
"type": "Program",
"start": 0,
"end": 60,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 60
}
},
"sourceType": "module",
"body": [
{
"type": "DeclareFunction",
"start": 0,
"end": 60,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 60
}
},
"id": {
"type": "Identifier",
"start": 17,
"end": 59,
"loc": {
"start": {
"line": 1,
"column": 17
},
"end": {
"line": 1,
"column": 59
},
"identifierName": "foo"
},
"name": "foo",
"typeAnnotation": {
"type": "TypeAnnotation",
"start": 20,
"end": 59,
"loc": {
"start": {
"line": 1,
"column": 20
},
"end": {
"line": 1,
"column": 59
}
},
"typeAnnotation": {
"type": "FunctionTypeAnnotation",
"start": 20,
"end": 59,
"loc": {
"start": {
"line": 1,
"column": 20
},
"end": {
"line": 1,
"column": 59
}
},
"typeParameters": null,
"params": [
{
"type": "FunctionTypeParam",
"start": 21,
"end": 29,
"loc": {
"start": {
"line": 1,
"column": 21
},
"end": {
"line": 1,
"column": 29
}
},
"name": {
"type": "Identifier",
"start": 21,
"end": 22,
"loc": {
"start": {
"line": 1,
"column": 21
},
"end": {
"line": 1,
"column": 22
},
"identifierName": "x"
},
"name": "x"
},
"optional": false,
"typeAnnotation": {
"type": "MixedTypeAnnotation",
"start": 24,
"end": 29,
"loc": {
"start": {
"line": 1,
"column": 24
},
"end": {
"line": 1,
"column": 29
}
}
}
}
],
"rest": null,
"returnType": {
"type": "BooleanTypeAnnotation",
"start": 32,
"end": 39,
"loc": {
"start": {
"line": 1,
"column": 32
},
"end": {
"line": 1,
"column": 39
}
}
}
},
"predicate": {
"type": "DeclaredPredicate",
"start": 40,
"end": 59,
"loc": {
"start": {
"line": 1,
"column": 40
},
"end": {
"line": 1,
"column": 59
}
},
"expression": {
"type": "BinaryExpression",
"start": 48,
"end": 58,
"loc": {
"start": {
"line": 1,
"column": 48
},
"end": {
"line": 1,
"column": 58
}
},
"left": {
"type": "Identifier",
"start": 48,
"end": 49,
"loc": {
"start": {
"line": 1,
"column": 48
},
"end": {
"line": 1,
"column": 49
},
"identifierName": "x"
},
"name": "x"
},
"operator": "!==",
"right": {
"type": "NullLiteral",
"start": 54,
"end": 58,
"loc": {
"start": {
"line": 1,
"column": 54
},
"end": {
"line": 1,
"column": 58
}
}
}
}
}
}
}
}
],
"directives": []
}
}

View File

@ -0,0 +1 @@
var f = (x: mixed): %checks => typeof x === "string";

View File

@ -0,0 +1,256 @@
{
"type": "File",
"start": 0,
"end": 53,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 53
}
},
"program": {
"type": "Program",
"start": 0,
"end": 53,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 53
}
},
"sourceType": "module",
"body": [
{
"type": "VariableDeclaration",
"start": 0,
"end": 53,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 53
}
},
"declarations": [
{
"type": "VariableDeclarator",
"start": 4,
"end": 52,
"loc": {
"start": {
"line": 1,
"column": 4
},
"end": {
"line": 1,
"column": 52
}
},
"id": {
"type": "Identifier",
"start": 4,
"end": 5,
"loc": {
"start": {
"line": 1,
"column": 4
},
"end": {
"line": 1,
"column": 5
},
"identifierName": "f"
},
"name": "f"
},
"init": {
"type": "ArrowFunctionExpression",
"start": 8,
"end": 52,
"loc": {
"start": {
"line": 1,
"column": 8
},
"end": {
"line": 1,
"column": 52
}
},
"returnType": {
"type": "TypeAnnotation",
"start": 18,
"end": 27,
"loc": {
"start": {
"line": 1,
"column": 18
},
"end": {
"line": 1,
"column": 27
}
},
"typeAnnotation": null,
"predicate": {
"type": "InferredPredicate",
"start": 20,
"end": 27,
"loc": {
"start": {
"line": 1,
"column": 20
},
"end": {
"line": 1,
"column": 27
}
}
}
},
"id": null,
"generator": false,
"expression": true,
"async": false,
"params": [
{
"type": "Identifier",
"start": 9,
"end": 17,
"loc": {
"start": {
"line": 1,
"column": 9
},
"end": {
"line": 1,
"column": 17
},
"identifierName": "x"
},
"name": "x",
"typeAnnotation": {
"type": "TypeAnnotation",
"start": 10,
"end": 17,
"loc": {
"start": {
"line": 1,
"column": 10
},
"end": {
"line": 1,
"column": 17
}
},
"typeAnnotation": {
"type": "MixedTypeAnnotation",
"start": 12,
"end": 17,
"loc": {
"start": {
"line": 1,
"column": 12
},
"end": {
"line": 1,
"column": 17
}
}
}
}
}
],
"body": {
"type": "BinaryExpression",
"start": 31,
"end": 52,
"loc": {
"start": {
"line": 1,
"column": 31
},
"end": {
"line": 1,
"column": 52
}
},
"left": {
"type": "UnaryExpression",
"start": 31,
"end": 39,
"loc": {
"start": {
"line": 1,
"column": 31
},
"end": {
"line": 1,
"column": 39
}
},
"operator": "typeof",
"prefix": true,
"argument": {
"type": "Identifier",
"start": 38,
"end": 39,
"loc": {
"start": {
"line": 1,
"column": 38
},
"end": {
"line": 1,
"column": 39
},
"identifierName": "x"
},
"name": "x"
},
"extra": {
"parenthesizedArgument": false
}
},
"operator": "===",
"right": {
"type": "StringLiteral",
"start": 44,
"end": 52,
"loc": {
"start": {
"line": 1,
"column": 44
},
"end": {
"line": 1,
"column": 52
}
},
"extra": {
"rawValue": "string",
"raw": "\"string\""
},
"value": "string"
}
}
}
}
],
"kind": "var"
}
],
"directives": []
}
}

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@ -0,0 +1 @@
function foo(x: mixed): %checks { return typeof x === "string"; };

View File

@ -0,0 +1,270 @@
{
"type": "File",
"start": 0,
"end": 66,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 66
}
},
"program": {
"type": "Program",
"start": 0,
"end": 66,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 66
}
},
"sourceType": "module",
"body": [
{
"type": "FunctionDeclaration",
"start": 0,
"end": 65,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 65
}
},
"id": {
"type": "Identifier",
"start": 9,
"end": 12,
"loc": {
"start": {
"line": 1,
"column": 9
},
"end": {
"line": 1,
"column": 12
},
"identifierName": "foo"
},
"name": "foo"
},
"generator": false,
"expression": false,
"async": false,
"params": [
{
"type": "Identifier",
"start": 13,
"end": 21,
"loc": {
"start": {
"line": 1,
"column": 13
},
"end": {
"line": 1,
"column": 21
},
"identifierName": "x"
},
"name": "x",
"typeAnnotation": {
"type": "TypeAnnotation",
"start": 14,
"end": 21,
"loc": {
"start": {
"line": 1,
"column": 14
},
"end": {
"line": 1,
"column": 21
}
},
"typeAnnotation": {
"type": "MixedTypeAnnotation",
"start": 16,
"end": 21,
"loc": {
"start": {
"line": 1,
"column": 16
},
"end": {
"line": 1,
"column": 21
}
}
}
}
}
],
"returnType": {
"type": "TypeAnnotation",
"start": 22,
"end": 31,
"loc": {
"start": {
"line": 1,
"column": 22
},
"end": {
"line": 1,
"column": 31
}
},
"typeAnnotation": null,
"predicate": {
"type": "InferredPredicate",
"start": 24,
"end": 31,
"loc": {
"start": {
"line": 1,
"column": 24
},
"end": {
"line": 1,
"column": 31
}
}
}
},
"body": {
"type": "BlockStatement",
"start": 32,
"end": 65,
"loc": {
"start": {
"line": 1,
"column": 32
},
"end": {
"line": 1,
"column": 65
}
},
"body": [
{
"type": "ReturnStatement",
"start": 34,
"end": 63,
"loc": {
"start": {
"line": 1,
"column": 34
},
"end": {
"line": 1,
"column": 63
}
},
"argument": {
"type": "BinaryExpression",
"start": 41,
"end": 62,
"loc": {
"start": {
"line": 1,
"column": 41
},
"end": {
"line": 1,
"column": 62
}
},
"left": {
"type": "UnaryExpression",
"start": 41,
"end": 49,
"loc": {
"start": {
"line": 1,
"column": 41
},
"end": {
"line": 1,
"column": 49
}
},
"operator": "typeof",
"prefix": true,
"argument": {
"type": "Identifier",
"start": 48,
"end": 49,
"loc": {
"start": {
"line": 1,
"column": 48
},
"end": {
"line": 1,
"column": 49
},
"identifierName": "x"
},
"name": "x"
},
"extra": {
"parenthesizedArgument": false
}
},
"operator": "===",
"right": {
"type": "StringLiteral",
"start": 54,
"end": 62,
"loc": {
"start": {
"line": 1,
"column": 54
},
"end": {
"line": 1,
"column": 62
}
},
"extra": {
"rawValue": "string",
"raw": "\"string\""
},
"value": "string"
}
}
}
],
"directives": []
}
},
{
"type": "EmptyStatement",
"start": 65,
"end": 66,
"loc": {
"start": {
"line": 1,
"column": 65
},
"end": {
"line": 1,
"column": 66
}
}
}
],
"directives": []
}
}

View File

@ -0,0 +1 @@
var f = (x: mixed): % checks => typeof x === "string";

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@ -0,0 +1,3 @@
{
"throws": "Unexpected token, expected ; (1:18)"
}

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@ -0,0 +1,3 @@
function foo(x): % checks {
return typeof x === "string";
}

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@ -0,0 +1,3 @@
{
"throws": "Spaces between ´%´ and ´checks´ are not allowed here. (1:17)"
}

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@ -0,0 +1 @@
declare function my_filter<T, P: $Pred<1>>(v: Array<T>, cb: P): Array<$Refine<T,P,1>>;

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@ -0,0 +1,599 @@
{
"type": "File",
"start": 0,
"end": 86,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 86
}
},
"program": {
"type": "Program",
"start": 0,
"end": 86,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 86
}
},
"sourceType": "module",
"body": [
{
"type": "DeclareFunction",
"start": 0,
"end": 86,
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 86
}
},
"id": {
"type": "Identifier",
"start": 17,
"end": 85,
"loc": {
"start": {
"line": 1,
"column": 17
},
"end": {
"line": 1,
"column": 85
},
"identifierName": "my_filter"
},
"name": "my_filter",
"typeAnnotation": {
"type": "TypeAnnotation",
"start": 26,
"end": 85,
"loc": {
"start": {
"line": 1,
"column": 26
},
"end": {
"line": 1,
"column": 85
}
},
"typeAnnotation": {
"type": "FunctionTypeAnnotation",
"start": 26,
"end": 85,
"loc": {
"start": {
"line": 1,
"column": 26
},
"end": {
"line": 1,
"column": 85
}
},
"typeParameters": {
"type": "TypeParameterDeclaration",
"start": 26,
"end": 42,
"loc": {
"start": {
"line": 1,
"column": 26
},
"end": {
"line": 1,
"column": 42
}
},
"params": [
{
"type": "TypeParameter",
"start": 27,
"end": 28,
"loc": {
"start": {
"line": 1,
"column": 27
},
"end": {
"line": 1,
"column": 28
}
},
"name": "T",
"variance": null
},
{
"type": "TypeParameter",
"start": 30,
"end": 41,
"loc": {
"start": {
"line": 1,
"column": 30
},
"end": {
"line": 1,
"column": 41
}
},
"name": "P",
"variance": null,
"bound": {
"type": "TypeAnnotation",
"start": 31,
"end": 41,
"loc": {
"start": {
"line": 1,
"column": 31
},
"end": {
"line": 1,
"column": 41
}
},
"typeAnnotation": {
"type": "GenericTypeAnnotation",
"start": 33,
"end": 41,
"loc": {
"start": {
"line": 1,
"column": 33
},
"end": {
"line": 1,
"column": 41
}
},
"typeParameters": {
"type": "TypeParameterInstantiation",
"start": 38,
"end": 41,
"loc": {
"start": {
"line": 1,
"column": 38
},
"end": {
"line": 1,
"column": 41
}
},
"params": [
{
"type": "NumericLiteralTypeAnnotation",
"start": 39,
"end": 40,
"loc": {
"start": {
"line": 1,
"column": 39
},
"end": {
"line": 1,
"column": 40
}
},
"value": 1,
"extra": {
"rawValue": 1,
"raw": "1"
}
}
]
},
"id": {
"type": "Identifier",
"start": 33,
"end": 38,
"loc": {
"start": {
"line": 1,
"column": 33
},
"end": {
"line": 1,
"column": 38
},
"identifierName": "$Pred"
},
"name": "$Pred"
}
}
}
}
]
},
"params": [
{
"type": "FunctionTypeParam",
"start": 43,
"end": 54,
"loc": {
"start": {
"line": 1,
"column": 43
},
"end": {
"line": 1,
"column": 54
}
},
"name": {
"type": "Identifier",
"start": 43,
"end": 44,
"loc": {
"start": {
"line": 1,
"column": 43
},
"end": {
"line": 1,
"column": 44
},
"identifierName": "v"
},
"name": "v"
},
"optional": false,
"typeAnnotation": {
"type": "GenericTypeAnnotation",
"start": 46,
"end": 54,
"loc": {
"start": {
"line": 1,
"column": 46
},
"end": {
"line": 1,
"column": 54
}
},
"typeParameters": {
"type": "TypeParameterInstantiation",
"start": 51,
"end": 54,
"loc": {
"start": {
"line": 1,
"column": 51
},
"end": {
"line": 1,
"column": 54
}
},
"params": [
{
"type": "GenericTypeAnnotation",
"start": 52,
"end": 53,
"loc": {
"start": {
"line": 1,
"column": 52
},
"end": {
"line": 1,
"column": 53
}
},
"typeParameters": null,
"id": {
"type": "Identifier",
"start": 52,
"end": 53,
"loc": {
"start": {
"line": 1,
"column": 52
},
"end": {
"line": 1,
"column": 53
},
"identifierName": "T"
},
"name": "T"
}
}
]
},
"id": {
"type": "Identifier",
"start": 46,
"end": 51,
"loc": {
"start": {
"line": 1,
"column": 46
},
"end": {
"line": 1,
"column": 51
},
"identifierName": "Array"
},
"name": "Array"
}
}
},
{
"type": "FunctionTypeParam",
"start": 56,
"end": 61,
"loc": {
"start": {
"line": 1,
"column": 56
},
"end": {
"line": 1,
"column": 61
}
},
"name": {
"type": "Identifier",
"start": 56,
"end": 58,
"loc": {
"start": {
"line": 1,
"column": 56
},
"end": {
"line": 1,
"column": 58
},
"identifierName": "cb"
},
"name": "cb"
},
"optional": false,
"typeAnnotation": {
"type": "GenericTypeAnnotation",
"start": 60,
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