src/lobject.c

   1 /*
   2 ** $Id: lobject.c,v 1.19 1999/04/13 19:28:49 roberto Exp $
   3 ** Some generic functions over Lua objects
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9
  10 #include "lobject.h"
  11 #include "lua.h"
  12
  13
  14 char *luaO_typenames[] = { /* ORDER LUA_T */
  15     "userdata", "number", "string", "table", "function", "function",
  16     "nil", "function", "mark", "mark", "mark", "line", NULL
  17 };
  18
  19
  20 TObject luaO_nilobject = {LUA_T_NIL, {NULL}};
  21
  22
  23
  24 /* hash dimensions values */
  25 static long dimensions[] =
  26  {5L, 11L, 23L, 47L, 97L, 197L, 397L, 797L, 1597L, 3203L, 6421L,
  27   12853L, 25717L, 51437L, 102811L, 205619L, 411233L, 822433L,
  28   1644817L, 3289613L, 6579211L, 13158023L, MAX_INT};
  29
  30
  31 int luaO_redimension (int oldsize)
  32 {
  33   int i;
  34   for (i=0; dimensions[i]<MAX_INT; i++) {
  35     if (dimensions[i] > oldsize)
  36       return dimensions[i];
  37   }
  38   lua_error("tableEM");
  39   return 0;  /* to avoid warnings */
  40 }
  41
  42
  43 int luaO_equalval (TObject *t1, TObject *t2) {
  44   switch (ttype(t1)) {
  45     case LUA_T_NIL: return 1;
  46     case LUA_T_NUMBER: return nvalue(t1) == nvalue(t2);
  47     case LUA_T_STRING: case LUA_T_USERDATA: return svalue(t1) == svalue(t2);
  48     case LUA_T_ARRAY: return avalue(t1) == avalue(t2);
  49     case LUA_T_PROTO: return tfvalue(t1)  == tfvalue(t2);
  50     case LUA_T_CPROTO: return fvalue(t1)  == fvalue(t2);
  51     case LUA_T_CLOSURE: return t1->value.cl == t2->value.cl;
  52     default:
  53      LUA_INTERNALERROR("invalid type");
  54      return 0; /* UNREACHABLE */
  55   }
  56 }
  57
  58
  59 void luaO_insertlist (GCnode *root, GCnode *node)
  60 {
  61   node->next = root->next;
  62   root->next = node;
  63   node->marked = 0;
  64 }
  65
  66
  67 #ifdef OLD_ANSI
  68 void luaO_memup (void *dest, void *src, int size) {
  69   while (size--)
  70     ((char *)dest)[size]=((char *)src)[size];
  71 }
  72
  73 void luaO_memdown (void *dest, void *src, int size) {
  74   int i;
  75   for (i=0; i<size; i++)
  76     ((char *)dest)[i]=((char *)src)[i];
  77 }
  78 #endif
  79
  80
  81
  82 static double expten (unsigned int e) {
  83   double exp = 10.0;
  84   double res = 1.0;
  85   for (; e; e>>=1) {
  86     if (e & 1) res *= exp;
  87     exp *= exp;
  88   }
  89   return res;
  90 }
  91
  92
  93 double luaO_str2d (char *s) {  /* LUA_NUMBER */
  94   double a = 0.0;
  95   int point = 0;
  96   while (isdigit((unsigned char)*s)) {
  97     a = 10.0*a + (*(s++)-'0');
  98   }
  99   if (*s == '.') {
 100     s++;
 101     while (isdigit((unsigned char)*s)) {
 102       a = 10.0*a + (*(s++)-'0');
 103       point++;
 104     }
 105   }
 106   if (toupper((unsigned char)*s) == 'E') {
 107     int e = 0;
 108     int sig = 1;
 109     s++;
 110     if (*s == '-') {
 111       s++;
 112       sig = -1;
 113     }
 114     else if (*s == '+') s++;
 115     if (!isdigit((unsigned char)*s)) return -1;  /* no digit in the exponent? */
 116     do {
 117       e = 10*e + (*(s++)-'0');
 118     } while (isdigit((unsigned char)*s));
 119     point -= sig*e;
 120   }
 121   while (isspace((unsigned char)*s)) s++;
 122   if (*s != '\0') return -1;  /* invalid trailing characters? */
 123   if (point > 0)
 124     a /= expten(point);
 125   else if (point < 0)
 126     a *= expten(-point);
 127   return a;
 128 }
 129