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git.saurik.com Git - redis.git/blob - deps/lua/src/llex.c
6dc319358c0f76a88dcc545e8c5375f85f7a569c
2 ** $Id: llex.c,v 2.20.1.1 2007/12/27 13:02:25 roberto Exp $
4 ** See Copyright Notice in lua.h
28 #define next(ls) (ls->current = zgetc(ls->z))
33 #define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r')
37 const char *const luaX_tokens
[] = {
38 "and", "break", "do", "else", "elseif",
39 "end", "false", "for", "function", "if",
40 "in", "local", "nil", "not", "or", "repeat",
41 "return", "then", "true", "until", "while",
42 "..", "...", "==", ">=", "<=", "~=",
43 "<number>", "<name>", "<string>", "<eof>",
48 #define save_and_next(ls) (save(ls, ls->current), next(ls))
51 static void save (LexState
*ls
, int c
) {
52 Mbuffer
*b
= ls
->buff
;
53 if (b
->n
+ 1 > b
->buffsize
) {
55 if (b
->buffsize
>= MAX_SIZET
/2)
56 luaX_lexerror(ls
, "lexical element too long", 0);
57 newsize
= b
->buffsize
* 2;
58 luaZ_resizebuffer(ls
->L
, b
, newsize
);
60 b
->buffer
[b
->n
++] = cast(char, c
);
64 void luaX_init (lua_State
*L
) {
66 for (i
=0; i
<NUM_RESERVED
; i
++) {
67 TString
*ts
= luaS_new(L
, luaX_tokens
[i
]);
68 luaS_fix(ts
); /* reserved words are never collected */
69 lua_assert(strlen(luaX_tokens
[i
])+1 <= TOKEN_LEN
);
70 ts
->tsv
.reserved
= cast_byte(i
+1); /* reserved word */
78 const char *luaX_token2str (LexState
*ls
, int token
) {
79 if (token
< FIRST_RESERVED
) {
80 lua_assert(token
== cast(unsigned char, token
));
81 return (iscntrl(token
)) ? luaO_pushfstring(ls
->L
, "char(%d)", token
) :
82 luaO_pushfstring(ls
->L
, "%c", token
);
85 return luaX_tokens
[token
-FIRST_RESERVED
];
89 static const char *txtToken (LexState
*ls
, int token
) {
95 return luaZ_buffer(ls
->buff
);
97 return luaX_token2str(ls
, token
);
102 void luaX_lexerror (LexState
*ls
, const char *msg
, int token
) {
104 luaO_chunkid(buff
, getstr(ls
->source
), MAXSRC
);
105 msg
= luaO_pushfstring(ls
->L
, "%s:%d: %s", buff
, ls
->linenumber
, msg
);
107 luaO_pushfstring(ls
->L
, "%s near " LUA_QS
, msg
, txtToken(ls
, token
));
108 luaD_throw(ls
->L
, LUA_ERRSYNTAX
);
112 void luaX_syntaxerror (LexState
*ls
, const char *msg
) {
113 luaX_lexerror(ls
, msg
, ls
->t
.token
);
117 TString
*luaX_newstring (LexState
*ls
, const char *str
, size_t l
) {
118 lua_State
*L
= ls
->L
;
119 TString
*ts
= luaS_newlstr(L
, str
, l
);
120 TValue
*o
= luaH_setstr(L
, ls
->fs
->h
, ts
); /* entry for `str' */
122 setbvalue(o
, 1); /* make sure `str' will not be collected */
127 static void inclinenumber (LexState
*ls
) {
128 int old
= ls
->current
;
129 lua_assert(currIsNewline(ls
));
130 next(ls
); /* skip `\n' or `\r' */
131 if (currIsNewline(ls
) && ls
->current
!= old
)
132 next(ls
); /* skip `\n\r' or `\r\n' */
133 if (++ls
->linenumber
>= MAX_INT
)
134 luaX_syntaxerror(ls
, "chunk has too many lines");
138 void luaX_setinput (lua_State
*L
, LexState
*ls
, ZIO
*z
, TString
*source
) {
141 ls
->lookahead
.token
= TK_EOS
; /* no look-ahead token */
147 luaZ_resizebuffer(ls
->L
, ls
->buff
, LUA_MINBUFFER
); /* initialize buffer */
148 next(ls
); /* read first char */
154 ** =======================================================
156 ** =======================================================
161 static int check_next (LexState
*ls
, const char *set
) {
162 if (!strchr(set
, ls
->current
))
169 static void buffreplace (LexState
*ls
, char from
, char to
) {
170 size_t n
= luaZ_bufflen(ls
->buff
);
171 char *p
= luaZ_buffer(ls
->buff
);
173 if (p
[n
] == from
) p
[n
] = to
;
177 static void trydecpoint (LexState
*ls
, SemInfo
*seminfo
) {
178 /* format error: try to update decimal point separator */
179 struct lconv
*cv
= localeconv();
180 char old
= ls
->decpoint
;
181 ls
->decpoint
= (cv
? cv
->decimal_point
[0] : '.');
182 buffreplace(ls
, old
, ls
->decpoint
); /* try updated decimal separator */
183 if (!luaO_str2d(luaZ_buffer(ls
->buff
), &seminfo
->r
)) {
184 /* format error with correct decimal point: no more options */
185 buffreplace(ls
, ls
->decpoint
, '.'); /* undo change (for error message) */
186 luaX_lexerror(ls
, "malformed number", TK_NUMBER
);
192 static void read_numeral (LexState
*ls
, SemInfo
*seminfo
) {
193 lua_assert(isdigit(ls
->current
));
196 } while (isdigit(ls
->current
) || ls
->current
== '.');
197 if (check_next(ls
, "Ee")) /* `E'? */
198 check_next(ls
, "+-"); /* optional exponent sign */
199 while (isalnum(ls
->current
) || ls
->current
== '_')
202 buffreplace(ls
, '.', ls
->decpoint
); /* follow locale for decimal point */
203 if (!luaO_str2d(luaZ_buffer(ls
->buff
), &seminfo
->r
)) /* format error? */
204 trydecpoint(ls
, seminfo
); /* try to update decimal point separator */
208 static int skip_sep (LexState
*ls
) {
211 lua_assert(s
== '[' || s
== ']');
213 while (ls
->current
== '=') {
217 return (ls
->current
== s
) ? count
: (-count
) - 1;
221 static void read_long_string (LexState
*ls
, SemInfo
*seminfo
, int sep
) {
223 (void)(cont
); /* avoid warnings when `cont' is not used */
224 save_and_next(ls
); /* skip 2nd `[' */
225 if (currIsNewline(ls
)) /* string starts with a newline? */
226 inclinenumber(ls
); /* skip it */
228 switch (ls
->current
) {
230 luaX_lexerror(ls
, (seminfo
) ? "unfinished long string" :
231 "unfinished long comment", TK_EOS
);
232 break; /* to avoid warnings */
233 #if defined(LUA_COMPAT_LSTR)
235 if (skip_sep(ls
) == sep
) {
236 save_and_next(ls
); /* skip 2nd `[' */
238 #if LUA_COMPAT_LSTR == 1
240 luaX_lexerror(ls
, "nesting of [[...]] is deprecated", '[');
247 if (skip_sep(ls
) == sep
) {
248 save_and_next(ls
); /* skip 2nd `]' */
249 #if defined(LUA_COMPAT_LSTR) && LUA_COMPAT_LSTR == 2
251 if (sep
== 0 && cont
>= 0) break;
261 if (!seminfo
) luaZ_resetbuffer(ls
->buff
); /* avoid wasting space */
265 if (seminfo
) save_and_next(ls
);
271 seminfo
->ts
= luaX_newstring(ls
, luaZ_buffer(ls
->buff
) + (2 + sep
),
272 luaZ_bufflen(ls
->buff
) - 2*(2 + sep
));
276 static void read_string (LexState
*ls
, int del
, SemInfo
*seminfo
) {
278 while (ls
->current
!= del
) {
279 switch (ls
->current
) {
281 luaX_lexerror(ls
, "unfinished string", TK_EOS
);
282 continue; /* to avoid warnings */
285 luaX_lexerror(ls
, "unfinished string", TK_STRING
);
286 continue; /* to avoid warnings */
289 next(ls
); /* do not save the `\' */
290 switch (ls
->current
) {
291 case 'a': c
= '\a'; break;
292 case 'b': c
= '\b'; break;
293 case 'f': c
= '\f'; break;
294 case 'n': c
= '\n'; break;
295 case 'r': c
= '\r'; break;
296 case 't': c
= '\t'; break;
297 case 'v': c
= '\v'; break;
298 case '\n': /* go through */
299 case '\r': save(ls
, '\n'); inclinenumber(ls
); continue;
300 case EOZ
: continue; /* will raise an error next loop */
302 if (!isdigit(ls
->current
))
303 save_and_next(ls
); /* handles \\, \", \', and \? */
308 c
= 10*c
+ (ls
->current
-'0');
310 } while (++i
<3 && isdigit(ls
->current
));
312 luaX_lexerror(ls
, "escape sequence too large", TK_STRING
);
326 save_and_next(ls
); /* skip delimiter */
327 seminfo
->ts
= luaX_newstring(ls
, luaZ_buffer(ls
->buff
) + 1,
328 luaZ_bufflen(ls
->buff
) - 2);
332 static int llex (LexState
*ls
, SemInfo
*seminfo
) {
333 luaZ_resetbuffer(ls
->buff
);
335 switch (ls
->current
) {
343 if (ls
->current
!= '-') return '-';
344 /* else is a comment */
346 if (ls
->current
== '[') {
347 int sep
= skip_sep(ls
);
348 luaZ_resetbuffer(ls
->buff
); /* `skip_sep' may dirty the buffer */
350 read_long_string(ls
, NULL
, sep
); /* long comment */
351 luaZ_resetbuffer(ls
->buff
);
355 /* else short comment */
356 while (!currIsNewline(ls
) && ls
->current
!= EOZ
)
361 int sep
= skip_sep(ls
);
363 read_long_string(ls
, seminfo
, sep
);
366 else if (sep
== -1) return '[';
367 else luaX_lexerror(ls
, "invalid long string delimiter", TK_STRING
);
371 if (ls
->current
!= '=') return '=';
372 else { next(ls
); return TK_EQ
; }
376 if (ls
->current
!= '=') return '<';
377 else { next(ls
); return TK_LE
; }
381 if (ls
->current
!= '=') return '>';
382 else { next(ls
); return TK_GE
; }
386 if (ls
->current
!= '=') return '~';
387 else { next(ls
); return TK_NE
; }
391 read_string(ls
, ls
->current
, seminfo
);
396 if (check_next(ls
, ".")) {
397 if (check_next(ls
, "."))
398 return TK_DOTS
; /* ... */
399 else return TK_CONCAT
; /* .. */
401 else if (!isdigit(ls
->current
)) return '.';
403 read_numeral(ls
, seminfo
);
411 if (isspace(ls
->current
)) {
412 lua_assert(!currIsNewline(ls
));
416 else if (isdigit(ls
->current
)) {
417 read_numeral(ls
, seminfo
);
420 else if (isalpha(ls
->current
) || ls
->current
== '_') {
421 /* identifier or reserved word */
425 } while (isalnum(ls
->current
) || ls
->current
== '_');
426 ts
= luaX_newstring(ls
, luaZ_buffer(ls
->buff
),
427 luaZ_bufflen(ls
->buff
));
428 if (ts
->tsv
.reserved
> 0) /* reserved word? */
429 return ts
->tsv
.reserved
- 1 + FIRST_RESERVED
;
438 return c
; /* single-char tokens (+ - / ...) */
446 void luaX_next (LexState
*ls
) {
447 ls
->lastline
= ls
->linenumber
;
448 if (ls
->lookahead
.token
!= TK_EOS
) { /* is there a look-ahead token? */
449 ls
->t
= ls
->lookahead
; /* use this one */
450 ls
->lookahead
.token
= TK_EOS
; /* and discharge it */
453 ls
->t
.token
= llex(ls
, &ls
->t
.seminfo
); /* read next token */
457 void luaX_lookahead (LexState
*ls
) {
458 lua_assert(ls
->lookahead
.token
== TK_EOS
);
459 ls
->lookahead
.token
= llex(ls
, &ls
->lookahead
.seminfo
);