commit d8d81ba891e32581cb92d4fc89e069dc2cad84f4
parent cf22133b69c9974060d3b488046461a8523b7fe7
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Fri, 16 Apr 2010 09:30:43 -0300
new escape sequence '\*' + several comments + moving options from
switch default into cases (as now locale is fixed)
Diffstat:
| M | llex.c | | | 104 | +++++++++++++++++++++++++++++++++++++++++++++++-------------------------------- |
1 file changed, 62 insertions(+), 42 deletions(-)
diff --git a/llex.c b/llex.c
@@ -1,5 +1,5 @@
/*
-** $Id: llex.c,v 2.35 2010/02/27 21:16:24 roberto Exp roberto $
+** $Id: llex.c,v 2.36 2010/04/05 16:35:37 roberto Exp roberto $
** Lexical Analyzer
** See Copyright Notice in lua.h
*/
@@ -117,21 +117,30 @@ void luaX_syntaxerror (LexState *ls, const char *msg) {
}
+/*
+** creates a new string and anchors it in function's table so that
+** it will not be collected until the end of the function's compilation
+** (by that time it should be anchored in function's prototype)
+*/
TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
lua_State *L = ls->L;
TValue *o; /* entry for `str' */
- TString *ts = luaS_newlstr(L, str, l);
- setsvalue2s(L, L->top++, ts); /* anchor string */
- o = luaH_setstr(L, ls->fs->h, ts);
+ TString *ts = luaS_newlstr(L, str, l); /* create new string */
+ setsvalue2s(L, L->top++, ts); /* temporarily anchor it in stack */
+ o = luaH_setstr(L, ls->fs->h, ts);
if (ttisnil(o)) {
- setbvalue(o, 1); /* make sure `str' will not be collected */
+ setbvalue(o, 1); /* t[string] = true */
luaC_checkGC(L);
}
- L->top--;
+ L->top--; /* remove string from stack */
return ts;
}
+/*
+** increment line number and skips newline sequence (any of
+** \n, \r, \n\r, or \r\n)
+*/
static void inclinenumber (LexState *ls) {
int old = ls->current;
lua_assert(currIsNewline(ls));
@@ -152,7 +161,7 @@ void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source) {
ls->linenumber = 1;
ls->lastline = 1;
ls->source = source;
- ls->envn = luaS_new(L, "_ENV");
+ ls->envn = luaS_new(L, "_ENV"); /* create env name */
luaS_fix(ls->envn); /* never collect this name */
luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */
next(ls); /* read first char */
@@ -176,6 +185,9 @@ static int check_next (LexState *ls, const char *set) {
}
+/*
+** change all characters 'from' in buffer to 'to'
+*/
static void buffreplace (LexState *ls, char from, char to) {
size_t n = luaZ_bufflen(ls->buff);
char *p = luaZ_buffer(ls->buff);
@@ -188,11 +200,14 @@ static void buffreplace (LexState *ls, char from, char to) {
#define getlocaledecpoint() (localeconv()->decimal_point[0])
#endif
+/*
+** in case of format error, try to change decimal point separator to
+** the one defined in the current locale and check again
+*/
static void trydecpoint (LexState *ls, SemInfo *seminfo) {
- /* format error: try to update decimal point separator */
char old = ls->decpoint;
ls->decpoint = getlocaledecpoint();
- buffreplace(ls, old, ls->decpoint); /* try updated decimal separator */
+ buffreplace(ls, old, ls->decpoint); /* try new decimal separator */
if (!luaO_str2d(luaZ_buffer(ls->buff), &seminfo->r)) {
/* format error with correct decimal point: no more options */
buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */
@@ -218,6 +233,10 @@ static void read_numeral (LexState *ls, SemInfo *seminfo) {
}
+/*
+** skip a sequence '[=*=[' or ']=*]' and return its number of '='s or
+** -1 if sequence is malformed
+*/
static int skip_sep (LexState *ls) {
int count = 0;
int s = ls->current;
@@ -248,8 +267,7 @@ static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
}
break;
}
- case '\n':
- case '\r': {
+ case '\n': case '\r': {
save(ls, '\n');
inclinenumber(ls);
if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */
@@ -310,7 +328,7 @@ static int readdecesc (LexState *ls) {
static void read_string (LexState *ls, int del, SemInfo *seminfo) {
- save_and_next(ls);
+ save_and_next(ls); /* keep delimiter (for error messages) */
while (ls->current != del) {
switch (ls->current) {
case EOZ:
@@ -335,6 +353,14 @@ static void read_string (LexState *ls, int del, SemInfo *seminfo) {
case '\n':
case '\r': save(ls, '\n'); inclinenumber(ls); continue;
case EOZ: continue; /* will raise an error next loop */
+ case '*': { /* skip following span of spaces */
+ next(ls); /* skip the '*' */
+ while (lisspace(ls->current)) {
+ if (currIsNewline(ls)) inclinenumber(ls);
+ else next(ls);
+ }
+ continue; /* do not save 'c' */
+ }
default: {
if (!lisdigit(ls->current))
c = ls->current; /* handles \\, \", \', and \? */
@@ -361,31 +387,34 @@ static int llex (LexState *ls, SemInfo *seminfo) {
luaZ_resetbuffer(ls->buff);
for (;;) {
switch (ls->current) {
- case '\n':
- case '\r': {
+ case '\n': case '\r': { /* line breaks */
inclinenumber(ls);
break;
}
- case '-': {
+ case ' ': case '\f': case '\t': case '\v': { /* spaces */
+ next(ls);
+ break;
+ }
+ case '-': { /* '-' or '--' (comment) */
next(ls);
if (ls->current != '-') return '-';
/* else is a comment */
next(ls);
- if (ls->current == '[') {
+ if (ls->current == '[') { /* long comment? */
int sep = skip_sep(ls);
luaZ_resetbuffer(ls->buff); /* `skip_sep' may dirty the buffer */
if (sep >= 0) {
- read_long_string(ls, NULL, sep); /* long comment */
- luaZ_resetbuffer(ls->buff);
+ read_long_string(ls, NULL, sep); /* skip long comment */
+ luaZ_resetbuffer(ls->buff); /* previous call may dirty the buff. */
break;
}
}
/* else short comment */
while (!currIsNewline(ls) && ls->current != EOZ)
- next(ls);
+ next(ls); /* skip until end of line (or end of file) */
break;
}
- case '[': {
+ case '[': { /* long string or simply '[' */
int sep = skip_sep(ls);
if (sep >= 0) {
read_long_string(ls, seminfo, sep);
@@ -414,39 +443,30 @@ static int llex (LexState *ls, SemInfo *seminfo) {
if (ls->current != '=') return '~';
else { next(ls); return TK_NE; }
}
- case '"':
- case '\'': {
+ case '"': case '\'': { /* short literal strings */
read_string(ls, ls->current, seminfo);
return TK_STRING;
}
- case '.': {
+ case '.': { /* '.', '..', '...', or number */
save_and_next(ls);
if (check_next(ls, ".")) {
if (check_next(ls, "."))
- return TK_DOTS; /* ... */
- else return TK_CONCAT; /* .. */
+ return TK_DOTS; /* '...' */
+ else return TK_CONCAT; /* '..' */
}
else if (!lisdigit(ls->current)) return '.';
- else {
- read_numeral(ls, seminfo);
- return TK_NUMBER;
- }
+ /* else go through */
+ }
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9': {
+ read_numeral(ls, seminfo);
+ return TK_NUMBER;
}
case EOZ: {
return TK_EOS;
}
default: {
- if (lisspace(ls->current)) {
- lua_assert(!currIsNewline(ls));
- next(ls);
- break;
- }
- else if (lisdigit(ls->current)) {
- read_numeral(ls, seminfo);
- return TK_NUMBER;
- }
- else if (lislalpha(ls->current)) {
- /* identifier or reserved word */
+ if (lislalpha(ls->current)) { /* identifier or reserved word? */
TString *ts;
do {
save_and_next(ls);
@@ -460,10 +480,10 @@ static int llex (LexState *ls, SemInfo *seminfo) {
return TK_NAME;
}
}
- else {
+ else { /* single-char tokens (+ - / ...) */
int c = ls->current;
next(ls);
- return c; /* single-char tokens (+ - / ...) */
+ return c;
}
}
}
