File size: 4,586 Bytes
3ce1a40 | 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 | /**
* Lexer for the CUDA-like kernel language.
*
* Emits a token stream with source offsets so parser and lowering errors can point
* at a line. Whitespace and comments are skipped; nothing is evaluated here.
*/
export const TokenType = {
IDENT: 'ident',
KEYWORD: 'keyword',
INT: 'int',
FLOAT: 'float',
PUNCT: 'punct',
EOF: 'eof',
};
const KEYWORDS = new Set([
'__global__',
'__device__',
'__shared__',
'void',
'int',
'uint',
'float',
'double',
'const',
'return',
'if',
'else',
'while',
'for',
'break',
'continue',
'true',
'false',
]);
/** Multi-character operators are matched before single-character ones. */
const PUNCTUATORS = [
'&&', '||', '==', '!=', '<=', '>=', '<<', '>>', '+=', '-=', '*=', '/=', '%=',
'++', '--', '->',
'{', '}', '(', ')', '[', ']', ';', ',', '<', '>', '=', '+', '-', '*', '/', '%', '!', '&', '|', '^', '~', '.',
];
export class LexError extends Error {
constructor(message, line, column) {
super(`${message} (line ${line}, column ${column})`);
this.name = 'LexError';
this.line = line;
this.column = column;
}
}
const isDigit = (c) => c >= '0' && c <= '9';
const isIdentStart = (c) => /[A-Za-z_]/.test(c);
const isIdentPart = (c) => /[A-Za-z0-9_]/.test(c);
export function tokenize(source) {
const tokens = [];
let i = 0;
let line = 1;
let lineStart = 0;
const column = (offset) => offset - lineStart + 1;
while (i < source.length) {
const c = source[i];
if (c === '\n') {
i += 1;
line += 1;
lineStart = i;
continue;
}
if (c === ' ' || c === '\t' || c === '\r') {
i += 1;
continue;
}
// Comments run to end of line.
if (c === '/' && source[i + 1] === '/') {
while (i < source.length && source[i] !== '\n') i += 1;
continue;
}
if (c === '/' && source[i + 1] === '*') {
const startLine = line;
const startColumn = column(i);
i += 2;
for (;;) {
if (i >= source.length) throw new LexError('Unterminated block comment', startLine, startColumn);
if (source[i] === '\n') {
line += 1;
i += 1;
lineStart = i;
continue;
}
if (source[i] === '*' && source[i + 1] === '/') {
i += 2;
break;
}
i += 1;
}
continue;
}
// Identifiers, keywords and __global__-style qualifiers.
if (isIdentStart(c)) {
const start = i;
while (i < source.length && isIdentPart(source[i])) i += 1;
const value = source.slice(start, i);
tokens.push({
type: KEYWORDS.has(value) ? TokenType.KEYWORD : TokenType.IDENT,
value,
line,
column: column(start),
offset: start,
});
continue;
}
// Numbers: decimal and 0x hex, with optional fractional part and f suffix.
if (isDigit(c) || (c === '.' && isDigit(source[i + 1]))) {
const start = i;
let isFloat = false;
if (c === '0' && (source[i + 1] === 'x' || source[i + 1] === 'X')) {
i += 2;
while (i < source.length && /[0-9a-fA-F]/.test(source[i])) i += 1;
} else {
while (i < source.length && isDigit(source[i])) i += 1;
if (source[i] === '.') {
isFloat = true;
i += 1;
while (i < source.length && isDigit(source[i])) i += 1;
}
if (source[i] === 'e' || source[i] === 'E') {
isFloat = true;
i += 1;
if (source[i] === '+' || source[i] === '-') i += 1;
while (i < source.length && isDigit(source[i])) i += 1;
}
}
if (source[i] === 'f' || source[i] === 'F') {
isFloat = true;
i += 1;
}
const text = source.slice(start, i);
if (i < source.length && isIdentStart(source[i])) {
throw new LexError(`Malformed numeric literal '${text}${source[i]}'`, line, column(start));
}
tokens.push({ type: isFloat ? TokenType.FLOAT : TokenType.INT, value: text, line, column: column(start), offset: start });
continue;
}
// Punctuators, longest match first.
const punct = PUNCTUATORS.find((p) => source.startsWith(p, i));
if (punct) {
const start = i;
i += punct.length;
tokens.push({ type: TokenType.PUNCT, value: punct, line, column: column(start), offset: start });
continue;
}
throw new LexError(`Unexpected character '${c}'`, line, column(i));
}
tokens.push({ type: TokenType.EOF, value: '<end of input>', line, column: column(i), offset: i });
return tokens;
}
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