forked from microsoft/TypeScript
-
Notifications
You must be signed in to change notification settings - Fork 3
/
formattingScanner.ts
309 lines (263 loc) · 12.4 KB
/
formattingScanner.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/* @internal */
namespace ts.formatting {
const standardScanner = createScanner(ScriptTarget.Latest, /*skipTrivia*/ false, LanguageVariant.Standard);
const jsxScanner = createScanner(ScriptTarget.Latest, /*skipTrivia*/ false, LanguageVariant.JSX);
export interface FormattingScanner {
advance(): void;
getStartPos(): number;
isOnToken(): boolean;
isOnEOF(): boolean;
readTokenInfo(n: Node): TokenInfo;
readEOFTokenRange(): TextRangeWithKind;
getCurrentLeadingTrivia(): TextRangeWithKind[] | undefined;
lastTrailingTriviaWasNewLine(): boolean;
skipToEndOf(node: Node | NodeArray<Node>): void;
skipToStartOf(node: Node): void;
}
const enum ScanAction {
Scan,
RescanGreaterThanToken,
RescanSlashToken,
RescanTemplateToken,
RescanJsxIdentifier,
RescanJsxText,
RescanJsxAttributeValue,
}
export function getFormattingScanner<T>(text: string, languageVariant: LanguageVariant, startPos: number, endPos: number, cb: (scanner: FormattingScanner) => T): T {
const scanner = languageVariant === LanguageVariant.JSX ? jsxScanner : standardScanner;
scanner.setText(text);
scanner.setTextPos(startPos);
let wasNewLine = true;
let leadingTrivia: TextRangeWithTriviaKind[] | undefined;
let trailingTrivia: TextRangeWithTriviaKind[] | undefined;
let savedPos: number;
let lastScanAction: ScanAction | undefined;
let lastTokenInfo: TokenInfo | undefined;
const res = cb({
advance,
readTokenInfo,
readEOFTokenRange,
isOnToken,
isOnEOF,
getCurrentLeadingTrivia: () => leadingTrivia,
lastTrailingTriviaWasNewLine: () => wasNewLine,
skipToEndOf,
skipToStartOf,
getStartPos: () => lastTokenInfo?.token.pos ?? scanner.getTokenPos(),
});
lastTokenInfo = undefined;
scanner.setText(undefined);
return res;
function advance(): void {
lastTokenInfo = undefined;
const isStarted = scanner.getStartPos() !== startPos;
if (isStarted) {
wasNewLine = !!trailingTrivia && last(trailingTrivia).kind === SyntaxKind.NewLineTrivia;
}
else {
scanner.scan();
}
leadingTrivia = undefined;
trailingTrivia = undefined;
let pos = scanner.getStartPos();
// Read leading trivia and token
while (pos < endPos) {
const t = scanner.getToken();
if (!isTrivia(t)) {
break;
}
// consume leading trivia
scanner.scan();
const item: TextRangeWithTriviaKind = {
pos,
end: scanner.getStartPos(),
kind: t
};
pos = scanner.getStartPos();
leadingTrivia = append(leadingTrivia, item);
}
savedPos = scanner.getStartPos();
}
function shouldRescanGreaterThanToken(node: Node): boolean {
switch (node.kind) {
case SyntaxKind.GreaterThanEqualsToken:
case SyntaxKind.GreaterThanGreaterThanEqualsToken:
case SyntaxKind.GreaterThanGreaterThanGreaterThanEqualsToken:
case SyntaxKind.GreaterThanGreaterThanGreaterThanToken:
case SyntaxKind.GreaterThanGreaterThanToken:
return true;
}
return false;
}
function shouldRescanJsxIdentifier(node: Node): boolean {
if (node.parent) {
switch (node.parent.kind) {
case SyntaxKind.JsxAttribute:
case SyntaxKind.JsxOpeningElement:
case SyntaxKind.JsxClosingElement:
case SyntaxKind.JsxSelfClosingElement:
// May parse an identifier like `module-layout`; that will be scanned as a keyword at first, but we should parse the whole thing to get an identifier.
return isKeyword(node.kind) || node.kind === SyntaxKind.Identifier;
}
}
return false;
}
function shouldRescanJsxText(node: Node): boolean {
return isJsxText(node) || isJsxElement(node) && lastTokenInfo?.token.kind === SyntaxKind.JsxText;
}
function shouldRescanSlashToken(container: Node): boolean {
return container.kind === SyntaxKind.RegularExpressionLiteral;
}
function shouldRescanTemplateToken(container: Node): boolean {
return container.kind === SyntaxKind.TemplateMiddle ||
container.kind === SyntaxKind.TemplateTail;
}
function shouldRescanJsxAttributeValue(node: Node): boolean {
return node.parent && isJsxAttribute(node.parent) && node.parent.initializer === node;
}
function startsWithSlashToken(t: SyntaxKind): boolean {
return t === SyntaxKind.SlashToken || t === SyntaxKind.SlashEqualsToken;
}
function readTokenInfo(n: Node): TokenInfo {
Debug.assert(isOnToken());
// normally scanner returns the smallest available token
// check the kind of context node to determine if scanner should have more greedy behavior and consume more text.
const expectedScanAction = shouldRescanGreaterThanToken(n) ? ScanAction.RescanGreaterThanToken :
shouldRescanSlashToken(n) ? ScanAction.RescanSlashToken :
shouldRescanTemplateToken(n) ? ScanAction.RescanTemplateToken :
shouldRescanJsxIdentifier(n) ? ScanAction.RescanJsxIdentifier :
shouldRescanJsxText(n) ? ScanAction.RescanJsxText :
shouldRescanJsxAttributeValue(n) ? ScanAction.RescanJsxAttributeValue :
ScanAction.Scan;
if (lastTokenInfo && expectedScanAction === lastScanAction) {
// readTokenInfo was called before with the same expected scan action.
// No need to re-scan text, return existing 'lastTokenInfo'
// it is ok to call fixTokenKind here since it does not affect
// what portion of text is consumed. In contrast rescanning can change it,
// i.e. for '>=' when originally scanner eats just one character
// and rescanning forces it to consume more.
return fixTokenKind(lastTokenInfo, n);
}
if (scanner.getStartPos() !== savedPos) {
Debug.assert(lastTokenInfo !== undefined);
// readTokenInfo was called before but scan action differs - rescan text
scanner.setTextPos(savedPos);
scanner.scan();
}
let currentToken = getNextToken(n, expectedScanAction);
const token = createTextRangeWithKind(
scanner.getStartPos(),
scanner.getTextPos(),
currentToken,
);
// consume trailing trivia
if (trailingTrivia) {
trailingTrivia = undefined;
}
while (scanner.getStartPos() < endPos) {
currentToken = scanner.scan();
if (!isTrivia(currentToken)) {
break;
}
const trivia = createTextRangeWithKind(
scanner.getStartPos(),
scanner.getTextPos(),
currentToken,
);
if (!trailingTrivia) {
trailingTrivia = [];
}
trailingTrivia.push(trivia);
if (currentToken === SyntaxKind.NewLineTrivia) {
// move past new line
scanner.scan();
break;
}
}
lastTokenInfo = { leadingTrivia, trailingTrivia, token };
return fixTokenKind(lastTokenInfo, n);
}
function getNextToken(n: Node, expectedScanAction: ScanAction): SyntaxKind {
const token = scanner.getToken();
lastScanAction = ScanAction.Scan;
switch (expectedScanAction) {
case ScanAction.RescanGreaterThanToken:
if (token === SyntaxKind.GreaterThanToken) {
lastScanAction = ScanAction.RescanGreaterThanToken;
const newToken = scanner.reScanGreaterToken();
Debug.assert(n.kind === newToken);
return newToken;
}
break;
case ScanAction.RescanSlashToken:
if (startsWithSlashToken(token)) {
lastScanAction = ScanAction.RescanSlashToken;
const newToken = scanner.reScanSlashToken();
Debug.assert(n.kind === newToken);
return newToken;
}
break;
case ScanAction.RescanTemplateToken:
if (token === SyntaxKind.CloseBraceToken) {
lastScanAction = ScanAction.RescanTemplateToken;
return scanner.reScanTemplateToken(/* isTaggedTemplate */ false);
}
break;
case ScanAction.RescanJsxIdentifier:
lastScanAction = ScanAction.RescanJsxIdentifier;
return scanner.scanJsxIdentifier();
case ScanAction.RescanJsxText:
lastScanAction = ScanAction.RescanJsxText;
return scanner.reScanJsxToken(/* allowMultilineJsxText */ false);
case ScanAction.RescanJsxAttributeValue:
lastScanAction = ScanAction.RescanJsxAttributeValue;
return scanner.reScanJsxAttributeValue();
case ScanAction.Scan:
break;
default:
Debug.assertNever(expectedScanAction);
}
return token;
}
function readEOFTokenRange(): TextRangeWithKind<SyntaxKind.EndOfFileToken> {
Debug.assert(isOnEOF());
return createTextRangeWithKind(scanner.getStartPos(), scanner.getTextPos(), SyntaxKind.EndOfFileToken);
}
function isOnToken(): boolean {
const current = lastTokenInfo ? lastTokenInfo.token.kind : scanner.getToken();
return current !== SyntaxKind.EndOfFileToken && !isTrivia(current);
}
function isOnEOF(): boolean {
const current = lastTokenInfo ? lastTokenInfo.token.kind : scanner.getToken();
return current === SyntaxKind.EndOfFileToken;
}
// when containing node in the tree is token
// but its kind differs from the kind that was returned by the scanner,
// then kind needs to be fixed. This might happen in cases
// when parser interprets token differently, i.e keyword treated as identifier
function fixTokenKind(tokenInfo: TokenInfo, container: Node): TokenInfo {
if (isToken(container) && tokenInfo.token.kind !== container.kind) {
tokenInfo.token.kind = container.kind;
}
return tokenInfo;
}
function skipToEndOf(node: Node | NodeArray<Node>): void {
scanner.setTextPos(node.end);
savedPos = scanner.getStartPos();
lastScanAction = undefined;
lastTokenInfo = undefined;
wasNewLine = false;
leadingTrivia = undefined;
trailingTrivia = undefined;
}
function skipToStartOf(node: Node): void {
scanner.setTextPos(node.pos);
savedPos = scanner.getStartPos();
lastScanAction = undefined;
lastTokenInfo = undefined;
wasNewLine = false;
leadingTrivia = undefined;
trailingTrivia = undefined;
}
}
}