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Merged
merged 3 commits into from
May 13, 2018
Merged

Allow keywords in named import/export syntax #107

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5478400
Allow keywords in named import/export syntax
alangpierce May 12, 2018
360ffa3
Switch from booleans to an IdentifierHandling enum
alangpierce May 12, 2018
f1e3c6f
Consolidate into a skip accepting IdentifierHandling
alangpierce May 13, 2018
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19 changes: 10 additions & 9 deletions src/parser.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,8 @@ import {
Tokenizer,
Token,
Range,
CommentHandler
CommentHandler,
IdentifierHandling
} from "./tokenizer";

import {
Expand Down Expand Up @@ -1565,7 +1566,7 @@ export class Parser extends DiagnosticEmitter {
var setStart: i32 = 0;
var setEnd: i32 = 0;
if (tn.skip(Token.GET)) {
if (tn.peek(true, true) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
if (tn.peek(true, IdentifierHandling.PREFER) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
flags |= CommonFlags.GET;
isGetter = true;
setStart = tn.tokenPos;
Expand All @@ -1580,7 +1581,7 @@ export class Parser extends DiagnosticEmitter {
tn.reset(state);
}
} else if (tn.skip(Token.SET)) {
if (tn.peek(true, true) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
if (tn.peek(true, IdentifierHandling.PREFER) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
flags |= CommonFlags.SET | CommonFlags.SET;
isSetter = true;
setStart = tn.tokenPos;
Expand Down Expand Up @@ -1930,7 +1931,7 @@ export class Parser extends DiagnosticEmitter {
let identifier = Node.createIdentifierExpression(tn.readIdentifier(), tn.range());
let asIdentifier: IdentifierExpression | null = null;
if (tn.skip(Token.AS)) {
if (tn.skip(Token.IDENTIFIER)) {
if (tn.skipIdentifierName()) {
asIdentifier = Node.createIdentifierExpression(tn.readIdentifier(), tn.range());
} else {
this.error(
Expand Down Expand Up @@ -2044,7 +2045,7 @@ export class Parser extends DiagnosticEmitter {

// before: Identifier ('as' Identifier)?

if (tn.skip(Token.IDENTIFIER)) {
if (tn.skipIdentifierName()) {
let identifier = Node.createIdentifierExpression(tn.readIdentifier(), tn.range());
let asIdentifier: IdentifierExpression | null = null;
if (tn.skip(Token.AS)) {
Expand Down Expand Up @@ -2242,7 +2243,7 @@ export class Parser extends DiagnosticEmitter {

var identifier: IdentifierExpression | null = null;
if (tn.peek(true) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
tn.next(true);
tn.next(IdentifierHandling.PREFER);
identifier = Node.createIdentifierExpression(tn.readIdentifier(), tn.range());
}
var ret = Node.createBreakStatement(identifier, tn.range());
Expand All @@ -2258,7 +2259,7 @@ export class Parser extends DiagnosticEmitter {

var identifier: IdentifierExpression | null = null;
if (tn.peek(true) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
tn.next(true);
tn.next(IdentifierHandling.PREFER);
identifier = Node.createIdentifierExpression(tn.readIdentifier(), tn.range());
}
var ret = Node.createContinueStatement(identifier, tn.range());
Expand Down Expand Up @@ -2744,7 +2745,7 @@ export class Parser extends DiagnosticEmitter {
tn: Tokenizer
): Expression | null {

var token = tn.next(true);
var token = tn.next(IdentifierHandling.PREFER);
var startPos = tn.tokenPos;
var expr: Expression | null = null;

Expand Down Expand Up @@ -2821,7 +2822,7 @@ export class Parser extends DiagnosticEmitter {
let state = tn.mark();
let again = true;
do {
switch (tn.next(true)) {
switch (tn.next(IdentifierHandling.PREFER)) {

// function expression
case Token.DOT_DOT_DOT: {
Expand Down
50 changes: 43 additions & 7 deletions src/tokenizer.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,12 @@ export enum Token {
ENDOFFILE
}

export enum IdentifierHandling {
DEFAULT,
PREFER,
ALWAYS
}

export function tokenFromKeyword(text: string): Token {
switch (text.length && text.charCodeAt(0)) {
case CharCode.a: {
Expand Down Expand Up @@ -523,12 +529,15 @@ export class Tokenizer extends DiagnosticEmitter {
}
}

next(preferIdentifier: bool = false): Token {
next(identifierHandling: IdentifierHandling = IdentifierHandling.DEFAULT): Token {
this.nextToken = -1;
return this.token = this.unsafeNext(preferIdentifier);
return this.token = this.unsafeNext(identifierHandling);
}

private unsafeNext(preferIdentifier: bool = false, maxTokenLength: i32 = i32.MAX_VALUE): Token {
private unsafeNext(
identifierHandling: IdentifierHandling = IdentifierHandling.DEFAULT,
maxTokenLength: i32 = i32.MAX_VALUE
): Token {
var text = this.source.text;
while (this.pos < this.end) {
this.tokenPos = this.pos;
Expand Down Expand Up @@ -908,7 +917,11 @@ export class Tokenizer extends DiagnosticEmitter {
let keywordToken = tokenFromKeyword(keywordText);
if (
keywordToken != Token.INVALID &&
!(preferIdentifier && tokenIsAlsoIdentifier(keywordToken))
identifierHandling !== IdentifierHandling.ALWAYS &&
!(
identifierHandling === IdentifierHandling.PREFER &&
tokenIsAlsoIdentifier(keywordToken)
)
) {
return keywordToken;
}
Expand All @@ -933,15 +946,15 @@ export class Tokenizer extends DiagnosticEmitter {

peek(
checkOnNewLine: bool = false,
preferIdentifier: bool = false,
identifierHandling: IdentifierHandling = IdentifierHandling.DEFAULT,
maxCompoundLength: i32 = i32.MAX_VALUE
): Token {
var text = this.source.text;
if (this.nextToken < 0) {
let posBefore = this.pos;
let tokenBefore = this.token;
let tokenPosBefore = this.tokenPos;
this.nextToken = this.unsafeNext(preferIdentifier, maxCompoundLength);
this.nextToken = this.unsafeNext(identifierHandling, maxCompoundLength);
this.nextTokenPos = this.tokenPos;
if (checkOnNewLine) {
this.nextTokenOnNewLine = false;
Expand Down Expand Up @@ -970,7 +983,10 @@ export class Tokenizer extends DiagnosticEmitter {
break;
}
}
this.token = this.unsafeNext(token == Token.IDENTIFIER, maxCompoundLength);
this.token = this.unsafeNext(
token == Token.IDENTIFIER ? IdentifierHandling.PREFER : IdentifierHandling.DEFAULT,
maxCompoundLength
);
if (this.token == token) {
this.nextToken = -1;
return true;
Expand All @@ -982,6 +998,26 @@ export class Tokenizer extends DiagnosticEmitter {
}
}

/**
* Skip any name token, whether or not it is a keyword.
*/
skipIdentifierName(): bool {
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Could this become an IdentifierHandling option on skip(), maybe? :)

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Make sense, yeah this copied function is a bit ugly. I guess it felt a bit weird given the special case in skip.

How about this: I get rid of the special case in skip and specify it using an optional param like you suggested. Then, to make the common case the most natural to write, I'll make skipIdentifier as a shorthand for skip(Token.IDENTIFIER, IdentifierHandling.PREFER) and keep skipIdentifierName as a shorthand for skip(Token.IDENTIFIER, IdentifierHandling.ALWAYS). Let me know what you think.

var posBefore = this.pos;
var tokenBefore = this.token;
var tokenPosBefore = this.tokenPos;
var maxCompoundLength = i32.MAX_VALUE;
this.token = this.unsafeNext(IdentifierHandling.ALWAYS, maxCompoundLength);
if (this.token == Token.IDENTIFIER) {
this.nextToken = -1;
return true;
} else {
this.pos = posBefore;
this.token = tokenBefore;
this.tokenPos = tokenPosBefore;
return false;
}
}

mark(): State {
var state: State;
if (reusableState) {
Expand Down
9 changes: 9 additions & 0 deletions tests/compiler/named-export-default.optimized.wat
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Original file line number Diff line number Diff line change
@@ -0,0 +1,9 @@
(module
(type $i (func (result i32)))
(memory $0 1)
(export "default" (func $named-export-default/get3))
(export "memory" (memory $0))
(func $named-export-default/get3 (; 0 ;) (type $i) (result i32)
(i32.const 3)
)
)
5 changes: 5 additions & 0 deletions tests/compiler/named-export-default.ts
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Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
function get3(): i32 {
return 3;
}

export {get3 as default};
12 changes: 12 additions & 0 deletions tests/compiler/named-export-default.untouched.wat
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Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
(module
(type $i (func (result i32)))
(global $HEAP_BASE i32 (i32.const 4))
(memory $0 1)
(export "default" (func $named-export-default/get3))
(export "memory" (memory $0))
(func $named-export-default/get3 (; 0 ;) (type $i) (result i32)
(return
(i32.const 3)
)
)
)
12 changes: 12 additions & 0 deletions tests/compiler/named-import-default.optimized.wat
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Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
(module
(type $i (func (result i32)))
(memory $0 1)
(export "getValue" (func $named-import-default/getValue))
(export "memory" (memory $0))
(func $named-export-default/get3 (; 0 ;) (type $i) (result i32)
(i32.const 3)
)
(func $named-import-default/getValue (; 1 ;) (type $i) (result i32)
(call $named-export-default/get3)
)
)
7 changes: 7 additions & 0 deletions tests/compiler/named-import-default.ts
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Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
import {
default as get3
} from "./named-export-default";

export function getValue(): i32 {
return get3();
}
17 changes: 17 additions & 0 deletions tests/compiler/named-import-default.untouched.wat
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Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
(module
(type $i (func (result i32)))
(global $HEAP_BASE i32 (i32.const 4))
(memory $0 1)
(export "getValue" (func $named-import-default/getValue))
(export "memory" (memory $0))
(func $named-export-default/get3 (; 0 ;) (type $i) (result i32)
(return
(i32.const 3)
)
)
(func $named-import-default/getValue (; 1 ;) (type $i) (result i32)
(return
(call $named-export-default/get3)
)
)
)