/*
 *
 * c h a r . c				-- Characters management
 *
 * Copyright © 1993-1997 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
 * 
 *
 * Permission to use, copy, and/or distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that both the above copyright notice and this permission notice appear in
 * all copies and derived works.  Fees for distribution or use of this
 * software or derived works may only be charged with express written
 * permission of the copyright holder.  
 * This software is provided ``as is'' without express or implied warranty.
 *
 * This software is a derivative work of other copyrighted softwares; the
 * copyright notices of these softwares are placed in the file COPYRIGHTS
 *
 *
 *           Author: Erick Gallesio [eg@kaolin.unice.fr]
 *    Creation date: ??????
 * Last file update: 14-Apr-1997 14:14
 */

#include <ctype.h>
#include "stk.h"

struct charelem {
  char *name;
  unsigned char value;
};

static struct charelem chartable [] = { 
  "null",       '\000',
  "bell",       '\007',
  "backspace",  '\010',
  "newline",    '\012',
  "page",       '\014',
  "return",     '\015',
  "escape",     '\033',
  "space",      '\040',
  "delete",     '\177',

  /* poeticless names */
  "nul",        '\000',
  "soh",        '\001',
  "stx",        '\002',
  "etx",        '\003',
  "eot",        '\004',
  "enq",        '\005',
  "ack",        '\006',
  "bel",        '\007',

  "bs",         '\010',
  "ht",         '\011',
  "tab",        '\011',
  "nl",         '\012',
  "vt",         '\013',
  "np",         '\014',
  "cr",         '\015',
  "so",         '\016',
  "si",         '\017',

  "dle",        '\020',
  "dc1",        '\021',
  "dc2",        '\022',
  "dc3",        '\023',
  "dc4",        '\024',
  "nak",        '\025',
  "syn",        '\026',
  "etb",        '\027',

  "can",        '\030',
  "em",         '\031',
  "sub",        '\032',
  "esc",        '\033',
  "fs",         '\034',
  "gs",         '\035',
  "rs",         '\036',
  "us",         '\037',

  "sp",		'\040',					  
  "del",	'\177',
  
  "",           '\000'};


static int my_strcmpi(register char *p1, register char *p2)
{
  for( ; tolower(*p1) == tolower(*p2); p1++, p2++) 
    if (!*p1) return 0;

  return tolower(*p1) - tolower(*p2);
}



unsigned char STk_string2char(char *s)
/* converts a char name to a char */
{
  register struct charelem *p;
  
  if (s[1] == '\000') return s[0];
  for (p=chartable; *(p->name); p++) {
    if (my_strcmpi(p->name, s) == 0) return p->value;
  }
  Err("Bad char name", NIL);
  return '\0'; /* never reached */
}

char *STk_char2string(unsigned char c)  /* convert a char to it's external rep. */
{
  static unsigned char result[2] = " ";  /* sets the \0 */
  register struct charelem *p;

  for (p=chartable; *(p->name); p++)
    if (p->value == c) return p->name;
  
  /* If we are here it's a "normal" char */
  *result = c;
  return result;
}

SCM STk_makechar(unsigned char c)
{
  SCM z;

#ifndef COMPACT_SMALL_CST
  NEWCELL(z,tc_char);
#endif
  SET_CHARACTER(z, (int) c);
  return z;
}


/**** Section 6.6 ****/

PRIMITIVE STk_charp(SCM obj)
{
  return CHARP(obj) ? Truth: Ntruth;
}

static int charcomp(SCM c1, SCM c2)
{
  if (NCHARP(c1)) Err("comparing char: bad char", c1); 
  if (NCHARP(c2)) Err("comparing char: bad char", c2);
  
  return (CHAR(c1) - CHAR(c2));
}

static int charcompi(SCM c1, SCM c2)
{
  if (NCHARP(c1)) Err("comparing char: bad char", c1); 
  if (NCHARP(c2)) Err("comparing char: bad char", c2);
  
  return (tolower(CHAR(c1)) - tolower(CHAR(c2)));
}
  
PRIMITIVE STk_chareq   (SCM c1, SCM c2){return (charcomp(c1,c2)==0) ?Truth: Ntruth;}
PRIMITIVE STk_charless (SCM c1, SCM c2){return (charcomp(c1,c2)<0)  ?Truth: Ntruth;}
PRIMITIVE STk_chargt   (SCM c1, SCM c2){return (charcomp(c1,c2)>0)  ?Truth: Ntruth;}
PRIMITIVE STk_charlesse(SCM c1, SCM c2){return (charcomp(c1,c2)<=0) ?Truth: Ntruth;}
PRIMITIVE STk_chargte  (SCM c1, SCM c2){return (charcomp(c1,c2)>=0) ?Truth: Ntruth;}

PRIMITIVE STk_chareqi   (SCM c1, SCM c2){return (charcompi(c1,c2)==0)?Truth:Ntruth;}
PRIMITIVE STk_charlessi (SCM c1, SCM c2){return (charcompi(c1,c2)<0) ?Truth:Ntruth;}
PRIMITIVE STk_chargti   (SCM c1, SCM c2){return (charcompi(c1,c2)>0) ?Truth:Ntruth;}
PRIMITIVE STk_charlessei(SCM c1, SCM c2){return (charcompi(c1,c2)<=0)?Truth:Ntruth;}
PRIMITIVE STk_chargtei  (SCM c1, SCM c2){return (charcompi(c1,c2)>=0)?Truth:Ntruth;}

PRIMITIVE STk_char_alphap(SCM c)
{
  if (NCHARP(c)) Err("char-alphabetic?: bad character", c);
  return isalpha(CHAR(c))? Truth: Ntruth;
}

PRIMITIVE STk_char_numericp(SCM c)
{
  if (NCHARP(c)) Err("char-numeric?: bad character", c);
  return isdigit(CHAR(c))? Truth: Ntruth;
}

PRIMITIVE STk_char_whitep(SCM c)
{
  if (NCHARP(c)) Err("char-whitespace?: bad character", c);
  return isspace(CHAR(c))? Truth: Ntruth;
}

PRIMITIVE STk_char_upperp(SCM c)
{
  if (NCHARP(c)) Err("char-upper-case?: bad character", c);
  return isupper(CHAR(c))? Truth: Ntruth;
}

PRIMITIVE STk_char_lowerp(SCM c)
{
  if (NCHARP(c)) Err("char-lower-case?: bad character", c);
  return islower(CHAR(c))? Truth: Ntruth;
}

PRIMITIVE STk_char2integer(SCM c)
{
  if (NCHARP(c)) Err("char->integer: bad character", c);
  return STk_makeinteger((long) CHAR(c));
}

PRIMITIVE STk_integer2char(SCM i)
{
  int c = STk_integer_value(i);

  if (c < 0 || c > MAX_CHAR_CODE) Err("integer->char: bad integer", i);
  return STk_makechar(c);
}

PRIMITIVE STk_char_upper(SCM c)
{
  if (NCHARP(c)) Err("char-upcase: bad character", c);
  return STk_makechar(toupper(CHAR(c)));
}

PRIMITIVE STk_char_lower(SCM c)
{
  if (NCHARP(c)) Err("char-downcase: bad character", c);
  return STk_makechar(tolower(CHAR(c)));
}