new API function 'lua_cvtonum' to convert a value (number or string)

to a number, following the rules of the language to create integers
or floats
This commit is contained in:
Roberto Ierusalimschy 2013-05-14 13:00:11 -03:00
parent 36e8771076
commit b5ec26101f
2 changed files with 26 additions and 2 deletions

24
lapi.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lapi.c,v 2.178 2013/04/29 17:12:50 roberto Exp roberto $
** $Id: lapi.c,v 2.179 2013/05/02 12:37:24 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@ -331,6 +331,28 @@ LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
}
LUA_API int lua_cvtonum (lua_State *L, int idx) {
TValue *o = index2addr(L, idx);
if (ttisnumber(o)) return 1; /* already a number? */
else if (!ttisstring(o)) return 0; /* only strings can be converted */
else {
lua_Integer i; lua_Number n;
const char *s = svalue(o);
size_t len = tsvalue(o)->len;
if (luaO_str2int(s, len, &i)) {
setivalue(o, i);
return 1;
}
else if (luaO_str2d(s, len, &n)) {
setivalue(o, i);
setnvalue(o, n);
return 1;
}
else return 0;
}
}
LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) {
lua_Number n;
const TValue *o = index2addr(L, idx);

4
lua.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lua.h,v 1.287 2013/04/26 13:07:53 roberto Exp roberto $
** $Id: lua.h,v 1.288 2013/04/26 15:39:25 roberto Exp roberto $
** Lua - A Scripting Language
** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
** See Copyright Notice at the end of this file
@ -307,6 +307,8 @@ LUA_API int (lua_next) (lua_State *L, int idx);
LUA_API void (lua_concat) (lua_State *L, int n);
LUA_API void (lua_len) (lua_State *L, int idx);
LUA_API int (lua_cvtonum) (lua_State *L, int idx);
LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);
LUA_API void (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);