compiler/
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std/
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collections/
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module/
parser/
resolver/
scanner/
alloc.rad
4.2 KiB
ast.rad
22.4 KiB
gen.rad
489 B
il.rad
15.1 KiB
lower.rad
259.5 KiB
module.rad
13.4 KiB
package.rad
1.2 KiB
parser.rad
78.5 KiB
resolver.rad
244.3 KiB
scanner.rad
18.1 KiB
sexpr.rad
6.3 KiB
strings.rad
2.2 KiB
sys/
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65 B
collections.rad
36 B
fmt.rad
3.8 KiB
intrinsics.rad
399 B
io.rad
1.2 KiB
lang.rad
222 B
mem.rad
2.1 KiB
sys.rad
167 B
testing.rad
2.3 KiB
tests.rad
11.6 KiB
vec.rad
3.1 KiB
std.rad
231 B
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353 B
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112 B
LICENSE
1.1 KiB
Makefile
3.0 KiB
README
2.5 KiB
std.lib
1.0 KiB
std.lib.test
252 B
lib/std/lang/scanner.rad
raw
| 1 | //! Lexical scanner for the Radiance programming language. |
| 2 | //! |
| 3 | //! This module implements a hand-written scanner that tokenizes Radiance |
| 4 | //! source code into a stream of tokens for consumption by the parser. |
| 5 | @test mod tests; |
| 6 | |
| 7 | use std::mem; |
| 8 | use std::lang::strings; |
| 9 | |
| 10 | /// Token kinds representing all lexical elements in Radiance. |
| 11 | /// |
| 12 | /// This enum covers operators, keywords, literals, and structural |
| 13 | /// elements used by the parser to build the AST. |
| 14 | pub union TokenKind { |
| 15 | /// Special end of file token generated when the input is exhausted. |
| 16 | Eof, |
| 17 | /// Special invalid token. |
| 18 | Invalid, |
| 19 | |
| 20 | LParen, // ( |
| 21 | RParen, // ) |
| 22 | LBrace, // { |
| 23 | RBrace, // } |
| 24 | LBracket, // [ |
| 25 | RBracket, // ] |
| 26 | Comma, // , |
| 27 | Dot, // . |
| 28 | DotDot, // .. |
| 29 | Minus, // - |
| 30 | Plus, // + |
| 31 | Colon, // : |
| 32 | ColonColon, // :: |
| 33 | Semicolon, // ; |
| 34 | Slash, // / |
| 35 | Star, // * |
| 36 | Percent, // % |
| 37 | Amp, // & |
| 38 | Pipe, // | |
| 39 | Caret, // ^ |
| 40 | Tilde, // ~ |
| 41 | Underscore, // _ |
| 42 | Question, // ? |
| 43 | Bang, // ! |
| 44 | BangEqual, // != |
| 45 | Equal, // = |
| 46 | EqualEqual, // == |
| 47 | Gt, // > |
| 48 | GtEqual, // >= |
| 49 | Lt, // < |
| 50 | LtEqual, // <= |
| 51 | LtLt, // << |
| 52 | GtGt, // >> |
| 53 | Arrow, // -> |
| 54 | FatArrow, // => |
| 55 | |
| 56 | // Compound assignment operators. |
| 57 | PlusEqual, // += |
| 58 | MinusEqual, // -= |
| 59 | StarEqual, // *= |
| 60 | SlashEqual, // /= |
| 61 | PercentEqual, // %= |
| 62 | AmpEqual, // &= |
| 63 | PipeEqual, // |= |
| 64 | CaretEqual, // ^= |
| 65 | LtLtEqual, // <<= |
| 66 | GtGtEqual, // >>= |
| 67 | |
| 68 | // Boolean operators. |
| 69 | Not, And, Or, |
| 70 | |
| 71 | /// Eg. `fnord` |
| 72 | Ident, |
| 73 | /// Eg. `@default` |
| 74 | AtIdent, |
| 75 | /// The `log` keyword. |
| 76 | Log, |
| 77 | |
| 78 | // Literals. |
| 79 | String, // "fnord" |
| 80 | Char, // 'f' |
| 81 | Number, // 42 |
| 82 | True, // true |
| 83 | False, // false |
| 84 | Nil, // nil |
| 85 | Undefined, // undefined |
| 86 | |
| 87 | // Control flow tokens. |
| 88 | If, Else, Return, Break, |
| 89 | Continue, While, For, In, |
| 90 | Loop, Match, Case, Try, Catch, |
| 91 | Throw, Throws, Panic, Assert, |
| 92 | |
| 93 | // Variable binding tokens. |
| 94 | Let, Mut, Const, Align, |
| 95 | |
| 96 | // Module-related tokens. |
| 97 | Mod, Use, Super, |
| 98 | |
| 99 | // Type or function attributes. |
| 100 | Pub, Extern, Static, |
| 101 | |
| 102 | // Trait-related tokens. |
| 103 | Trait, Instance, |
| 104 | |
| 105 | // Type-related tokens. |
| 106 | I8, I16, I32, I64, U8, U16, U32, U64, |
| 107 | Opaque, Fn, Bool, Union, Record, As |
| 108 | } |
| 109 | |
| 110 | /// A reserved keyword. |
| 111 | record Keyword { |
| 112 | /// Keyword string. |
| 113 | name: *[u8], |
| 114 | /// Corresponding token. |
| 115 | tok: TokenKind, |
| 116 | } |
| 117 | |
| 118 | /// Sorted keyword table for binary search. |
| 119 | const KEYWORDS: [Keyword; 51] = [ |
| 120 | { name: "align", tok: TokenKind::Align }, |
| 121 | { name: "and", tok: TokenKind::And }, |
| 122 | { name: "as", tok: TokenKind::As }, |
| 123 | { name: "assert", tok: TokenKind::Assert }, |
| 124 | { name: "bool", tok: TokenKind::Bool }, |
| 125 | { name: "break", tok: TokenKind::Break }, |
| 126 | { name: "case", tok: TokenKind::Case }, |
| 127 | { name: "catch", tok: TokenKind::Catch }, |
| 128 | { name: "const", tok: TokenKind::Const }, |
| 129 | { name: "continue", tok: TokenKind::Continue }, |
| 130 | { name: "else", tok: TokenKind::Else }, |
| 131 | { name: "extern", tok: TokenKind::Extern }, |
| 132 | { name: "false", tok: TokenKind::False }, |
| 133 | { name: "fn", tok: TokenKind::Fn }, |
| 134 | { name: "for", tok: TokenKind::For }, |
| 135 | { name: "i16", tok: TokenKind::I16 }, |
| 136 | { name: "i32", tok: TokenKind::I32 }, |
| 137 | { name: "i64", tok: TokenKind::I64 }, |
| 138 | { name: "i8", tok: TokenKind::I8 }, |
| 139 | { name: "if", tok: TokenKind::If }, |
| 140 | { name: "in", tok: TokenKind::In }, |
| 141 | { name: "instance", tok: TokenKind::Instance }, |
| 142 | { name: "let", tok: TokenKind::Let }, |
| 143 | { name: "log", tok: TokenKind::Log }, |
| 144 | { name: "loop", tok: TokenKind::Loop }, |
| 145 | { name: "match", tok: TokenKind::Match }, |
| 146 | { name: "mod", tok: TokenKind::Mod }, |
| 147 | { name: "mut", tok: TokenKind::Mut }, |
| 148 | { name: "nil", tok: TokenKind::Nil }, |
| 149 | { name: "not", tok: TokenKind::Not }, |
| 150 | { name: "opaque", tok: TokenKind::Opaque }, |
| 151 | { name: "or", tok: TokenKind::Or }, |
| 152 | { name: "panic", tok: TokenKind::Panic }, |
| 153 | { name: "pub", tok: TokenKind::Pub }, |
| 154 | { name: "record", tok: TokenKind::Record }, |
| 155 | { name: "return", tok: TokenKind::Return }, |
| 156 | { name: "static", tok: TokenKind::Static }, |
| 157 | { name: "super", tok: TokenKind::Super }, |
| 158 | { name: "throw", tok: TokenKind::Throw }, |
| 159 | { name: "throws", tok: TokenKind::Throws }, |
| 160 | { name: "trait", tok: TokenKind::Trait }, |
| 161 | { name: "true", tok: TokenKind::True }, |
| 162 | { name: "try", tok: TokenKind::Try }, |
| 163 | { name: "u16", tok: TokenKind::U16 }, |
| 164 | { name: "u32", tok: TokenKind::U32 }, |
| 165 | { name: "u64", tok: TokenKind::U64 }, |
| 166 | { name: "u8", tok: TokenKind::U8 }, |
| 167 | { name: "undefined", tok: TokenKind::Undefined }, |
| 168 | { name: "union", tok: TokenKind::Union }, |
| 169 | { name: "use", tok: TokenKind::Use }, |
| 170 | { name: "while", tok: TokenKind::While }, |
| 171 | ]; |
| 172 | |
| 173 | /// Describes where source code originated from. |
| 174 | pub union SourceLoc { |
| 175 | /// Source loaded from a file at the given path. |
| 176 | File(*[u8]), |
| 177 | /// Source provided as an inline string (no file path). |
| 178 | String, |
| 179 | } |
| 180 | |
| 181 | /// Lexical scanner state for tokenizing Radiance source code. |
| 182 | /// |
| 183 | /// Maintains position information and source buffer reference. |
| 184 | pub record Scanner { |
| 185 | /// Origin of the source being scanned. |
| 186 | sourceLoc: SourceLoc, |
| 187 | /// Source buffer. |
| 188 | source: *[u8], |
| 189 | /// Offset of current token into buffer. |
| 190 | token: u32, |
| 191 | /// Offset of current character being scanned. |
| 192 | cursor: u32, |
| 193 | /// Interned string pool. |
| 194 | pool: *mut strings::Pool, |
| 195 | } |
| 196 | |
| 197 | /// Individual token with kind, source text, and position. |
| 198 | /// |
| 199 | /// Represents a single lexical element extracted from source, |
| 200 | /// including its original text and byte offset for error reporting. |
| 201 | pub record Token { |
| 202 | /// Token kind. |
| 203 | kind: TokenKind, |
| 204 | /// Token source string. |
| 205 | source: *[u8], |
| 206 | /// Byte offset of `source` in input buffer. |
| 207 | offset: u32, |
| 208 | } |
| 209 | |
| 210 | /// Source code location with line/column information. |
| 211 | /// |
| 212 | /// Used for error reporting and debugging. |
| 213 | pub record Location { |
| 214 | /// Origin of the source. |
| 215 | source: SourceLoc, |
| 216 | /// Line number. |
| 217 | line: u16, |
| 218 | /// Column number. |
| 219 | col: u16, |
| 220 | } |
| 221 | |
| 222 | /// Create a new scanner object. |
| 223 | pub fn scanner(sourceLoc: SourceLoc, source: *[u8], pool: *mut strings::Pool) -> Scanner { |
| 224 | // Intern built-in functions and attributes. |
| 225 | strings::intern(pool, "@sizeOf"); |
| 226 | strings::intern(pool, "@alignOf"); |
| 227 | strings::intern(pool, "@sliceOf"); |
| 228 | strings::intern(pool, "@default"); |
| 229 | strings::intern(pool, "@intrinsic"); |
| 230 | strings::intern(pool, "@test"); |
| 231 | // Intern built-in slice methods. |
| 232 | strings::intern(pool, "append"); |
| 233 | strings::intern(pool, "delete"); |
| 234 | |
| 235 | return Scanner { sourceLoc, source, token: 0, cursor: 0, pool }; |
| 236 | } |
| 237 | |
| 238 | /// Check if we've reached the end of input. |
| 239 | pub fn isEof(s: *Scanner) -> bool { |
| 240 | return s.cursor >= s.source.len; |
| 241 | } |
| 242 | |
| 243 | /// Get the current character, if any. |
| 244 | pub fn current(s: *Scanner) -> ?u8 { |
| 245 | if isEof(s) { |
| 246 | return nil; |
| 247 | } |
| 248 | return s.source[s.cursor]; |
| 249 | } |
| 250 | |
| 251 | /// Peek at the next character without advancing the scanner. |
| 252 | fn peek(s: *Scanner) -> ?u8 { |
| 253 | if s.cursor + 1 >= s.source.len { |
| 254 | return nil; |
| 255 | } |
| 256 | return s.source[s.cursor + 1]; |
| 257 | } |
| 258 | |
| 259 | /// Advance scanner and return the character that was consumed. |
| 260 | fn advance(s: *mut Scanner) -> u8 { |
| 261 | s.cursor += 1; |
| 262 | return s.source[s.cursor - 1]; |
| 263 | } |
| 264 | |
| 265 | /// Consume the expected character if it matches the current position. |
| 266 | fn consume(s: *mut Scanner, expected: u8) -> bool { |
| 267 | if let c = current(s); c == expected { |
| 268 | advance(s); |
| 269 | return true; |
| 270 | } |
| 271 | return false; |
| 272 | } |
| 273 | |
| 274 | /// Create a token from the current scanner state. |
| 275 | fn tok(s: *Scanner, kind: TokenKind) -> Token { |
| 276 | return Token { kind, source: &s.source[s.token..s.cursor], offset: s.token }; |
| 277 | } |
| 278 | |
| 279 | /// Create an invalid token with the given message. |
| 280 | pub fn invalid(offset: u32, message: *[u8]) -> Token { |
| 281 | return Token { kind: TokenKind::Invalid, source: message, offset }; |
| 282 | } |
| 283 | |
| 284 | /// Skip whitespace characters and line comments. |
| 285 | fn skipWhitespace(s: *mut Scanner) { |
| 286 | while let ch = current(s) { |
| 287 | match ch { |
| 288 | case ' ', '\n', '\r', '\t' => advance(s), |
| 289 | case '/' => { |
| 290 | if let c = peek(s); c == '/' { |
| 291 | while let ch = current(s); ch != '\n' { |
| 292 | advance(s); |
| 293 | } |
| 294 | } else { |
| 295 | return; |
| 296 | } |
| 297 | } |
| 298 | else => return, |
| 299 | } |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | /// Check if character is an ASCII digit (0-9). |
| 304 | fn isDigit(c: u8) -> bool { |
| 305 | return c >= '0' and c <= '9'; |
| 306 | } |
| 307 | |
| 308 | /// Check if character is a hexadecimal digit (0-9, a-f, A-F). |
| 309 | fn isHexDigit(c: u8) -> bool { |
| 310 | return (c >= '0' and c <= '9') |
| 311 | or (c >= 'a' and c <= 'f') |
| 312 | or (c >= 'A' and c <= 'F'); |
| 313 | } |
| 314 | |
| 315 | /// Check if character is a binary digit (0 or 1). |
| 316 | fn isBinDigit(c: u8) -> bool { |
| 317 | return c == '0' or c == '1'; |
| 318 | } |
| 319 | |
| 320 | /// Check if character is alphabetic. |
| 321 | fn isAlpha(c: u8) -> bool { |
| 322 | return (c >= 'a' and c <= 'z') |
| 323 | or (c >= 'A' and c <= 'Z'); |
| 324 | } |
| 325 | |
| 326 | /// Check if character is printable ASCII. |
| 327 | fn isPrint(c: u8) -> bool { |
| 328 | return c >= ' ' and c <= '~'; |
| 329 | } |
| 330 | |
| 331 | /// Scan numeric literal (decimal, hex, or binary). |
| 332 | fn scanNumber(s: *mut Scanner) -> Token { |
| 333 | let first = s.source[s.cursor - 1]; |
| 334 | if first == '-' or first == '+' { |
| 335 | advance(s); |
| 336 | } |
| 337 | // Check for hex literal (`0x` or `0X` prefix). |
| 338 | if s.source[s.cursor - 1] == '0' { |
| 339 | if let ch = current(s); ch == 'x' or ch == 'X' { |
| 340 | advance(s); |
| 341 | // Must have at least one hex digit after `0x`. |
| 342 | if let ch = current(s); not isHexDigit(ch) { |
| 343 | return invalid(s.token, "invalid hex literal"); |
| 344 | } |
| 345 | while let ch = current(s); isHexDigit(ch) { |
| 346 | advance(s); |
| 347 | } |
| 348 | return tok(s, TokenKind::Number); |
| 349 | } |
| 350 | // Check for binary literal (`0b` or `0B` prefix). |
| 351 | if let ch = current(s); ch == 'b' or ch == 'B' { |
| 352 | advance(s); |
| 353 | // Must have at least one binary digit after `0b`. |
| 354 | if let ch = current(s); not isBinDigit(ch) { |
| 355 | return invalid(s.token, "invalid binary literal"); |
| 356 | } |
| 357 | while let ch = current(s); isBinDigit(ch) { |
| 358 | advance(s); |
| 359 | } |
| 360 | return tok(s, TokenKind::Number); |
| 361 | } |
| 362 | } |
| 363 | |
| 364 | // Regular decimal number. |
| 365 | while let ch = current(s); isDigit(ch) { |
| 366 | advance(s); |
| 367 | } |
| 368 | |
| 369 | // Look for decimal part. |
| 370 | if let ch = current(s); ch == '.' { |
| 371 | if let p = peek(s); isDigit(p) { |
| 372 | advance(s); // Consume the "." |
| 373 | while let ch = current(s); isDigit(ch) { |
| 374 | advance(s); |
| 375 | } |
| 376 | } |
| 377 | } |
| 378 | return tok(s, TokenKind::Number); |
| 379 | } |
| 380 | |
| 381 | fn scanDelimited(s: *mut Scanner, delim: u8, kind: TokenKind) -> ?Token { |
| 382 | while let ch = current(s); ch != delim { |
| 383 | if not isPrint(ch) { |
| 384 | return invalid(s.token, "invalid character"); |
| 385 | } |
| 386 | consume(s, '\\'); // Consume escapes |
| 387 | advance(s); |
| 388 | } |
| 389 | if not consume(s, delim) { |
| 390 | return nil; |
| 391 | } |
| 392 | return tok(s, kind); |
| 393 | } |
| 394 | |
| 395 | /// Scan string literal enclosed in double quotes. |
| 396 | fn scanString(s: *mut Scanner) -> Token { |
| 397 | if let tok = scanDelimited(s, '"', TokenKind::String) { |
| 398 | return tok; |
| 399 | } |
| 400 | return invalid(s.token, "unterminated string"); |
| 401 | } |
| 402 | |
| 403 | /// Scan character literal enclosed in single quotes. |
| 404 | fn scanChar(s: *mut Scanner) -> Token { |
| 405 | if let tok = scanDelimited(s, '\'', TokenKind::Char) { |
| 406 | return tok; |
| 407 | } |
| 408 | return invalid(s.token, "unterminated character"); |
| 409 | } |
| 410 | |
| 411 | /// Scan a keyword or an identifier. |
| 412 | fn keywordOrIdent(src: *[u8]) -> TokenKind { |
| 413 | let mut left: u32 = 0; |
| 414 | let mut right: u32 = KEYWORDS.len; |
| 415 | |
| 416 | while left < right { |
| 417 | let mid = left + ((right - left) / 2); |
| 418 | let kw = KEYWORDS[mid]; |
| 419 | let cmp = mem::cmp(src, kw.name); |
| 420 | |
| 421 | match cmp { |
| 422 | case -1 => right = mid, |
| 423 | case 1 => left = mid + 1, |
| 424 | else => return kw.tok, |
| 425 | } |
| 426 | } |
| 427 | return TokenKind::Ident; |
| 428 | } |
| 429 | |
| 430 | /// Scan an identifier, keyword, or label. |
| 431 | fn scanIdentifier(s: *mut Scanner) -> Token { |
| 432 | while let ch = current(s); isAlpha(ch) or isDigit(ch) or ch == '_' or ch == '#' { |
| 433 | advance(s); |
| 434 | } |
| 435 | let ident = &s.source[s.token..s.cursor]; |
| 436 | let kind = keywordOrIdent(ident); |
| 437 | |
| 438 | // Only intern actual identifiers, not keywords. |
| 439 | if kind == TokenKind::Ident { |
| 440 | return Token { kind, source: strings::intern(s.pool, ident), offset: s.token }; |
| 441 | } |
| 442 | return tok(s, kind); |
| 443 | } |
| 444 | |
| 445 | /// Scan the next token. |
| 446 | pub fn next(s: *mut Scanner) -> Token { |
| 447 | skipWhitespace(s); // Skip any whitespace between tokens. |
| 448 | s.token = s.cursor; // Token starts at current position. |
| 449 | |
| 450 | if isEof(s) { |
| 451 | return tok(s, TokenKind::Eof); |
| 452 | } |
| 453 | let c: u8 = advance(s); |
| 454 | |
| 455 | if isDigit(c) { |
| 456 | return scanNumber(s); |
| 457 | } |
| 458 | if isAlpha(c) { |
| 459 | return scanIdentifier(s); |
| 460 | } |
| 461 | match c { |
| 462 | case '\'' => return scanChar(s), |
| 463 | case '"' => return scanString(s), |
| 464 | case '(' => return tok(s, TokenKind::LParen), |
| 465 | case ')' => return tok(s, TokenKind::RParen), |
| 466 | case '{' => return tok(s, TokenKind::LBrace), |
| 467 | case '}' => return tok(s, TokenKind::RBrace), |
| 468 | case '[' => return tok(s, TokenKind::LBracket), |
| 469 | case ']' => return tok(s, TokenKind::RBracket), |
| 470 | case ';' => return tok(s, TokenKind::Semicolon), |
| 471 | case ',' => return tok(s, TokenKind::Comma), |
| 472 | case '.' => { |
| 473 | if consume(s, '.') { |
| 474 | return tok(s, TokenKind::DotDot); |
| 475 | } |
| 476 | return tok(s, TokenKind::Dot); |
| 477 | } |
| 478 | case ':' => { |
| 479 | if consume(s, ':') { |
| 480 | return tok(s, TokenKind::ColonColon); |
| 481 | } |
| 482 | return tok(s, TokenKind::Colon); |
| 483 | } |
| 484 | case '-' => { |
| 485 | if consume(s, '>') { |
| 486 | return tok(s, TokenKind::Arrow); |
| 487 | } |
| 488 | if consume(s, '=') { |
| 489 | return tok(s, TokenKind::MinusEqual); |
| 490 | } |
| 491 | // If followed by a digit, scan as negative number |
| 492 | if let ch = current(s); isDigit(ch) { |
| 493 | return scanNumber(s); |
| 494 | } |
| 495 | return tok(s, TokenKind::Minus); |
| 496 | } |
| 497 | case '+' => { |
| 498 | if consume(s, '=') { |
| 499 | return tok(s, TokenKind::PlusEqual); |
| 500 | } |
| 501 | if let ch = current(s); isDigit(ch) { |
| 502 | return scanNumber(s); |
| 503 | } |
| 504 | return tok(s, TokenKind::Plus); |
| 505 | } |
| 506 | case '/' => { |
| 507 | if consume(s, '=') { |
| 508 | return tok(s, TokenKind::SlashEqual); |
| 509 | } |
| 510 | return tok(s, TokenKind::Slash); |
| 511 | } |
| 512 | case '*' => { |
| 513 | if consume(s, '=') { |
| 514 | return tok(s, TokenKind::StarEqual); |
| 515 | } |
| 516 | return tok(s, TokenKind::Star); |
| 517 | } |
| 518 | case '%' => { |
| 519 | if consume(s, '=') { |
| 520 | return tok(s, TokenKind::PercentEqual); |
| 521 | } |
| 522 | return tok(s, TokenKind::Percent); |
| 523 | } |
| 524 | case '&' => { |
| 525 | if consume(s, '=') { |
| 526 | return tok(s, TokenKind::AmpEqual); |
| 527 | } |
| 528 | return tok(s, TokenKind::Amp); |
| 529 | } |
| 530 | case '?' => return tok(s, TokenKind::Question), |
| 531 | case '|' => { |
| 532 | if consume(s, '=') { |
| 533 | return tok(s, TokenKind::PipeEqual); |
| 534 | } |
| 535 | return tok(s, TokenKind::Pipe); |
| 536 | } |
| 537 | case '^' => { |
| 538 | if consume(s, '=') { |
| 539 | return tok(s, TokenKind::CaretEqual); |
| 540 | } |
| 541 | return tok(s, TokenKind::Caret); |
| 542 | } |
| 543 | case '~' => return tok(s, TokenKind::Tilde), |
| 544 | case '!' => { |
| 545 | if consume(s, '=') { |
| 546 | return tok(s, TokenKind::BangEqual); |
| 547 | } |
| 548 | return tok(s, TokenKind::Bang); |
| 549 | } |
| 550 | case '=' => { |
| 551 | if consume(s, '>') { |
| 552 | return tok(s, TokenKind::FatArrow); |
| 553 | } |
| 554 | if consume(s, '=') { |
| 555 | return tok(s, TokenKind::EqualEqual); |
| 556 | } |
| 557 | return tok(s, TokenKind::Equal); |
| 558 | } |
| 559 | case '<' => { |
| 560 | if consume(s, '<') { |
| 561 | if consume(s, '=') { |
| 562 | return tok(s, TokenKind::LtLtEqual); |
| 563 | } |
| 564 | return tok(s, TokenKind::LtLt); |
| 565 | } |
| 566 | if consume(s, '=') { |
| 567 | return tok(s, TokenKind::LtEqual); |
| 568 | } |
| 569 | return tok(s, TokenKind::Lt); |
| 570 | } |
| 571 | case '>' => { |
| 572 | if consume(s, '>') { |
| 573 | if consume(s, '=') { |
| 574 | return tok(s, TokenKind::GtGtEqual); |
| 575 | } |
| 576 | return tok(s, TokenKind::GtGt); |
| 577 | } |
| 578 | if consume(s, '=') { |
| 579 | return tok(s, TokenKind::GtEqual); |
| 580 | } |
| 581 | return tok(s, TokenKind::Gt); |
| 582 | } |
| 583 | case '@' => { |
| 584 | // Scan `@identifier` as a single token. |
| 585 | while let ch = current(s); isAlpha(ch) { |
| 586 | advance(s); |
| 587 | } |
| 588 | // Must have at least one character after `@`. |
| 589 | if s.cursor - s.token <= 1 { |
| 590 | return invalid(s.token, "expected identifier after `@`"); |
| 591 | } |
| 592 | let name = &s.source[s.token..s.cursor]; |
| 593 | return Token { |
| 594 | kind: TokenKind::AtIdent, |
| 595 | source: strings::intern(s.pool, name), |
| 596 | offset: s.token, |
| 597 | }; |
| 598 | } |
| 599 | case '_' => { |
| 600 | if let ch = current(s); isAlpha(ch) or isDigit(ch) or ch == '_' { |
| 601 | // This is part of an identifier like `_foo` or `__start` |
| 602 | return scanIdentifier(s); |
| 603 | } |
| 604 | return tok(s, TokenKind::Underscore); |
| 605 | } |
| 606 | else => return invalid(s.token, "unexpected character"), |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | /// Get the source code location from a byte offset. |
| 611 | pub fn getLocation(sourceLoc: SourceLoc, source: *[u8], offset: u32) -> ?Location { |
| 612 | let mut l: u16 = 1; |
| 613 | let mut c: u16 = 1; |
| 614 | |
| 615 | if offset >= source.len { |
| 616 | return nil; |
| 617 | } |
| 618 | for ch in &source[..offset] { |
| 619 | if ch == '\n' { |
| 620 | c = 1; |
| 621 | l += 1; |
| 622 | } else { |
| 623 | c += 1; |
| 624 | } |
| 625 | } |
| 626 | return Location { source: sourceLoc, line: l, col: c }; |
| 627 | } |