lua/lobject.c

/*
** $Id: lobject.c,v 1.54 2000/10/10 19:53:20 roberto Exp roberto $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lmem.h"
#include "lobject.h"
#include "lstate.h"



const TObject luaO_nilobject = {LUA_TNIL, {NULL}};


const char *const luaO_typenames[] = {
  "userdata", "nil", "number", "string", "table", "function"
};



/*
** returns smaller power of 2 larger than `n' (minimum is MINPOWER2) 
*/
lint32 luaO_power2 (lint32 n) {
  lint32 p = MINPOWER2;
  while (p<=n) p<<=1;
  return p;
}


int luaO_equalObj (const TObject *t1, const TObject *t2) {
  if (ttype(t1) != ttype(t2)) return 0;
  switch (ttype(t1)) {
    case LUA_TNUMBER:
      return nvalue(t1) == nvalue(t2);
    case LUA_TSTRING: case LUA_TUSERDATA:
      return tsvalue(t1) == tsvalue(t2);
    case LUA_TTABLE: 
      return hvalue(t1) == hvalue(t2);
    case LUA_TFUNCTION:
      return clvalue(t1) == clvalue(t2);
    default:
      LUA_ASSERT(ttype(t1) == LUA_TNIL, "invalid type");
      return 1; /* LUA_TNIL */
  }
}


char *luaO_openspace (lua_State *L, size_t n) {
  if (n > L->Mbuffsize) {
    luaM_reallocvector(L, L->Mbuffer, n, char);
    L->nblocks += (n - L->Mbuffsize)*sizeof(char);
    L->Mbuffsize = n;
  }
  return L->Mbuffer;
}


int luaO_str2d (const char *s, Number *result) {  /* LUA_NUMBER */
  char *endptr;
  Number res = lua_str2number(s, &endptr);
  if (endptr == s) return 0;  /* no conversion */
  while (isspace((unsigned char)*endptr)) endptr++;
  if (*endptr != '\0') return 0;  /* invalid trailing characters? */
  *result = res;
  return 1;
}


/* maximum length of a string format for `luaO_verror' */
#define MAX_VERROR	280

/* this function needs to handle only '%d' and '%.XXs' formats */
void luaO_verror (lua_State *L, const char *fmt, ...) {
  va_list argp;
  char buff[MAX_VERROR];  /* to hold formatted message */
  va_start(argp, fmt);
  vsprintf(buff, fmt, argp);
  va_end(argp);
  lua_error(L, buff);
}


void luaO_chunkid (char *out, const char *source, int bufflen) {
  if (*source == '=') {
    strncpy(out, source+1, bufflen);  /* remove first char */
    out[bufflen-1] = '\0';  /* ensures null termination */
  }
  else {
    if (*source == '@') {
      int l;
      source++;  /* skip the `@' */
      bufflen -= sizeof("file `...%s'");
      l = strlen(source);
      if (l>bufflen) {
        source += (l-bufflen);  /* get last part of file name */
        sprintf(out, "file `...%.99s'", source);
      }
      else
        sprintf(out, "file `%.99s'", source);
    }
    else {
      int len = strcspn(source, "\n");  /* stop at first newline */
      bufflen -= sizeof("string \"%.*s...\"");
      if (len > bufflen) len = bufflen;
      if (source[len] != '\0') {  /* must truncate? */
        strcpy(out, "string \"");
        out += strlen(out);
        strncpy(out, source, len);
        strcpy(out+len, "...\"");
      }
      else
        sprintf(out, "string \"%.99s\"", source);
    }
  }
}