mirror of https://github.com/lua/lua
115 lines
2.6 KiB
C
115 lines
2.6 KiB
C
/*
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** $Id: lobject.c,v 1.44 2000/08/09 19:16:57 roberto Exp roberto $
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** Some generic functions over Lua objects
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** See Copyright Notice in lua.h
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*/
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#include <ctype.h>
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#include <stdlib.h>
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#include "lua.h"
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#include "lobject.h"
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/*
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** you can use the fact that the 3rd letter or each name is always different
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** (e-m-r-b-n-l) to compare and switch these strings
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*/
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const char *const luaO_typenames[] = { /* ORDER LUA_T */
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"userdata", "number", "string", "table", "function", "function", "nil",
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"function", "function"
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};
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const TObject luaO_nilobject = {TAG_NIL, {NULL}};
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/*
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** returns smaller power of 2 larger than `n' (minimum is MINPOWER2)
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*/
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lint32 luaO_power2 (lint32 n) {
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lint32 p = MINPOWER2;
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while (p<=n) p<<=1;
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return p;
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}
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int luaO_equalObj (const TObject *t1, const TObject *t2) {
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if (ttype(t1) != ttype(t2)) return 0;
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switch (ttype(t1)) {
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case TAG_NUMBER:
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return nvalue(t1) == nvalue(t2);
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case TAG_STRING: case TAG_USERDATA:
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return tsvalue(t1) == tsvalue(t2);
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case TAG_TABLE:
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return hvalue(t1) == hvalue(t2);
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case TAG_CCLOSURE: case TAG_LCLOSURE:
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return clvalue(t1) == clvalue(t2);
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default:
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LUA_ASSERT(ttype(t1) == TAG_NIL, "invalid type");
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return 1; /* TAG_NIL */
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}
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}
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static double expten (unsigned int e) {
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double exp = 10.0;
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double res = 1.0;
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for (; e; e>>=1) {
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if (e & 1) res *= exp;
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exp *= exp;
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}
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return res;
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}
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int luaO_str2d (const char *s, Number *result) { /* LUA_NUMBER */
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double a = 0.0;
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int point = 0; /* number of decimal digits */
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int sig;
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while (isspace((unsigned char)*s)) s++;
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sig = 0;
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switch (*s) {
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case '-': sig = 1; /* go through */
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case '+': s++;
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}
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if (! (isdigit((unsigned char)*s) ||
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(*s == '.' && isdigit((unsigned char)*(s+1)))))
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return 0; /* not (at least one digit before or after the point) */
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while (isdigit((unsigned char)*s))
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a = 10.0*a + (*(s++)-'0');
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if (*s == '.') {
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s++;
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while (isdigit((unsigned char)*s)) {
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a = 10.0*a + (*(s++)-'0');
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point++;
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}
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}
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if (sig) a = -a;
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if (*s == 'e' || *s == 'E') {
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int e = 0;
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s++;
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sig = 0;
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switch (*s) {
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case '-': sig = 1; /* go through */
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case '+': s++;
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}
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if (!isdigit((unsigned char)*s)) return 0; /* no digit in the exponent? */
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do {
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e = 10*e + (*(s++)-'0');
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} while (isdigit((unsigned char)*s));
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if (sig) e = -e;
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point -= e;
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}
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while (isspace((unsigned char)*s)) s++;
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if (*s != '\0') return 0; /* invalid trailing characters? */
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if (point != 0) {
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if (point > 0) a /= expten(point);
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else a *= expten(-point);
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}
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*result = a;
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return 1;
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}
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