Lua enhancement
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- Subject: Lua enhancement
- From: "Ilja V.Levinson" <lev@...>
- Date: Mon, 28 Jul 97 15:39:03 -0500
Hi,
At this moment Lua lexer accepts only decimal numeric constants. I think,
that using octal/hexadecimal digits would be more comfortable for some
users. So, I wrote a simple patch to lex.c to implement this feature. It
seems, there is only one bug - a token '0x' is interpereted as number '0'.
I also think about to implement binary arithmetic commands like '&' - binary
AND, '|' - binary OR and '^' - binary XOR. I have a look into sources - this
will be a non-trivial work. '^' symbol also will conflict with pow()
function. May be, a '^^' or '**' (Ada-like) would be more suitable for pow()
?
Any suggestions?
Regards,
Ilja
---------------------------------------------------------------
All changes are between #ifdef _OSK/#endif
------------------------ cut here -----------------------------
*** orig/lex.c Mon Jul 28 14:29:00 1997
--- lex.c Mon Jul 28 15:19:00 1997
***************
*** 20,26 ****
--- 20,30 ----
#define next() (current = zgetc(lex_z))
+ #ifdef _OSK /* possible a bug too - yytext[] is not zeroed
automatically */
+ #define save(x) (yytext[tokensize++] = (x), yytext[tokensize] = '0円')
+ #else
#define save(x) (yytext[tokensize++] = (x))
+ #endif
#define save_and_next() (save(current), next())
***************
*** 272,277 ****
--- 276,284 ----
{
static int linelasttoken = 0;
double a;
+ #ifdef _OSK
+ double base;
+ #endif
int buffsize = MINBUFF;
char *yytext = luaI_buffer(buffsize);
yytext[1] = yytext[2] = yytext[3] = 0;
***************
*** 288,294 ****
--- 295,305 ----
linelasttoken = lua_linenumber;
continue;
+ #ifdef _OSK /* only OS-9 related, ignore this */
+ case ' ': case '\t': case '012円': /* CR: to avoid problems with DOS
*/
+ #else
case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS
*/
+ #endif
next();
continue;
***************
*** 412,423 ****
--- 423,471 ----
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
a=0.0;
+ #ifdef _OSK /* The main code */
+ base = 10.0;
+ if(current == '0') {
+ save_and_next();
+ if(current == 'x' || current == 'X') {
+ base = 16.0;
+ save_and_next();
+ }
+ else {
+ base = 8.0;
+ }
+ }
+
+ while (isxdigit((unsigned char)current)) {
+ int digit;
+
+ if(isdigit((unsigned char)current))
+ digit = current - '0';
+ else if(current >= 'a')
+ digit = current -'a' + 10;
+ else
+ digit = current -'A' + 10;
+
+ if(digit >= base)
+ luaI_syntaxerror(
+ "numeric constant contains digit beyond the radix");
+ a = base*a+digit;
+ save_and_next();
+ }
+ #else
do {
a=10.0*a+(current-'0');
save_and_next();
} while (isdigit((unsigned char)current));
+ #endif
+
if (current == '.') {
save_and_next();
+ #ifdef _OSK
+ if(base != 10.0)
+ luaI_syntaxerror(
+ "floating constant must be in radix 10 only");
+ #endif
if (current == '.')
luaI_syntaxerror(
"ambiguous syntax (decimal point x string concatenation)");
---------------------------------- cut here -----------------------
--
-----------------------------------------------------------------
Ilja V.Levinson | If fifty million people say a foolish
Yekaterinburg, Russia | thing, it is still a foolish thing.
lev@odusv.oduurl.ru | **********
-----------------------------------------------------------------