gtk/glib/gscanner.c

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * GScanner: Flexible lexical scanner for general purpose.
 * Copyright (C) 1997 Tim Janik
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#define		__gscanner_c__

#include	<stdlib.h>
#include	<string.h>
#include	<unistd.h>
#include	<errno.h>
#include	"glib.h"



/* --- defines --- */
#define	to_lower(c)				( \
	(guchar) (							\
	  ( (((guchar)(c))>='A' && ((guchar)(c))<='Z') * ('a'-'A') ) +	\
	  ( (((guchar)(c))>=192 && ((guchar)(c))<=214) * (224-192) ) +	\
	  ( (((guchar)(c))>=216 && ((guchar)(c))<=222) * (248-216) ) +	\
	  ((guchar)(c))							\
	)								\
)


/* --- typedefs --- */
typedef	struct	_GScannerHashVal	GScannerHashVal;

struct	_GScannerHashVal
{
  gchar		*key;
  gpointer	value;
};



/* --- variables --- */
static	GScannerConfig	g_scanner_config_template =
{
  (
   " \t\n"
   )			/* cset_skip_characters */,
  (
   G_CSET_a_2_z
   "_"
   G_CSET_A_2_Z
   )			/* cset_identifier_first */,
  (
   G_CSET_a_2_z
   "_0123456789"
   G_CSET_A_2_Z
   G_CSET_LATINS
   G_CSET_LATINC
   )			/* cset_identifier_nth */,
  ( "#\n" )		/* cpair_comment_single */,
  
  FALSE			/* case_sensitive */,
  
  TRUE			/* skip_comment_multi */,
  TRUE			/* skip_comment_single */,
  TRUE			/* scan_comment_multi */,
  TRUE			/* scan_identifier */,
  FALSE			/* scan_identifier_1char */,
  FALSE			/* scan_identifier_NULL */,
  TRUE			/* scan_symbols */,
  FALSE			/* scan_binary */,
  TRUE			/* scan_octal */,
  TRUE			/* scan_float */,
  TRUE			/* scan_hex */,
  FALSE			/* scan_hex_dollar */,
  TRUE			/* scan_string_sq */,
  TRUE			/* scan_string_dq */,
  TRUE			/* numbers_2_int */,
  FALSE			/* int_2_float */,
  FALSE			/* identifier_2_string */,
  TRUE			/* char_2_token */,
  FALSE			/* symbol_2_token */,
};


/* --- prototypes --- */
static	GScannerHashVal* g_scanner_lookup_internal (GScanner	*scanner,
						    const gchar	*symbol);
static	void	g_scanner_get_token_ll	(GScanner	*scanner,
					 GTokenType	*token_p,
					 GValue		*value_p,
					 guint		*line_p,
					 guint		*position_p);
static	void	g_scanner_get_token_i	(GScanner	*scanner,
					 GTokenType	*token_p,
					 GValue		*value_p,
					 guint		*line_p,
					 guint		*position_p);
static	void	g_scanner_free_value	(GTokenType	*token_p,
					 GValue		*value_p);

static	__inline__
gint		g_scanner_char_2_num	(guchar		c,
					 guchar		base);
static	guchar	g_scanner_peek_next_char(GScanner	*scanner);
static	guchar	g_scanner_get_char	(GScanner	*scanner,
					 guint		*line_p,
					 guint		*position_p);


/* --- functions --- */
static gint
g_scanner_char_2_num (guchar	c,
		      guchar	base)
{
  if (c >= '0' && c <= '9')
    c -= '0';
  else if (c >= 'A' && c <= 'Z')
    c -= 'A' - 10;
  else if (c >= 'a' && c <= 'z')
    c -= 'a' - 10;
  else
    return -1;
  
  if (c < base)
    return c;
  
  return -1;
}

GScanner*
g_scanner_new (GScannerConfig	*config_templ)
{
  register GScanner	*scanner;
  
  if (!config_templ)
    config_templ = &g_scanner_config_template;
  
  scanner = g_new0 (GScanner, 1);
  
  scanner->user_data = NULL;
  scanner->input_name = NULL;
  scanner->parse_errors	= 0;
  scanner->max_parse_errors = 0;
  
  scanner->config = g_new0 (GScannerConfig, 1);
  
  scanner->config->case_sensitive	= config_templ->case_sensitive;
  scanner->config->cset_skip_characters	= config_templ->cset_skip_characters;
  scanner->config->cset_identifier_first= config_templ->cset_identifier_first;
  scanner->config->cset_identifier_nth	= config_templ->cset_identifier_nth;
  scanner->config->cpair_comment_single	= config_templ->cpair_comment_single;
  scanner->config->skip_comment_multi	= config_templ->skip_comment_multi;
  scanner->config->skip_comment_single	= config_templ->skip_comment_single;
  scanner->config->scan_comment_multi	= config_templ->scan_comment_multi;
  scanner->config->scan_identifier	= config_templ->scan_identifier;
  scanner->config->scan_identifier_1char= config_templ->scan_identifier_1char;
  scanner->config->scan_identifier_NULL	= config_templ->scan_identifier_NULL;
  scanner->config->scan_symbols		= config_templ->scan_symbols;
  scanner->config->scan_binary		= config_templ->scan_binary;
  scanner->config->scan_octal		= config_templ->scan_octal;
  scanner->config->scan_float		= config_templ->scan_float;
  scanner->config->scan_hex		= config_templ->scan_hex;
  scanner->config->scan_hex_dollar	= config_templ->scan_hex_dollar;
  scanner->config->scan_string_sq	= config_templ->scan_string_sq;
  scanner->config->scan_string_dq	= config_templ->scan_string_dq;
  scanner->config->numbers_2_int	= config_templ->numbers_2_int;
  scanner->config->int_2_float		= config_templ->int_2_float;
  scanner->config->identifier_2_string	= config_templ->identifier_2_string;
  scanner->config->char_2_token		= config_templ->char_2_token;
  scanner->config->symbol_2_token	= config_templ->symbol_2_token;
  
  scanner->token = G_TOKEN_NONE;
  scanner->value.v_int = 0;
  scanner->line = 1;
  scanner->position = 0;
  
  scanner->next_token = G_TOKEN_NONE;
  scanner->next_value.v_int = 0;
  scanner->next_line = 1;
  scanner->next_position = 0;
  
  scanner->symbol_table = g_hash_table_new (g_string_hash, g_string_equal);
  scanner->text = NULL;
  scanner->text_len = 0;
  scanner->input_fd = -1;
  scanner->peeked_char = -1;
  
  return scanner;
}

void
g_scanner_destroy (GScanner	*scanner)
{
  g_return_if_fail (scanner != NULL);
  
  g_hash_table_destroy (scanner->symbol_table);
  g_scanner_free_value (&scanner->token, &scanner->value);
  g_scanner_free_value (&scanner->next_token, &scanner->next_value);
  g_free (scanner->config);
  g_free (scanner);
}

void
g_scanner_input_file (GScanner	*scanner,
		      gint	input_fd)
{
  g_return_if_fail (input_fd >= 0);
  
  scanner->token = G_TOKEN_NONE;
  scanner->value.v_int = 0;
  scanner->line = 1;
  scanner->position = 0;
  scanner->next_token = G_TOKEN_NONE;
  
  scanner->text = NULL;
  scanner->text_len = 0;
  scanner->input_fd = input_fd;
  scanner->peeked_char = -1;
}

void
g_scanner_input_text (GScanner	     *scanner,
		      const  gchar   *text,
		      guint	     text_len)
{
  g_return_if_fail (text != NULL);
  
  scanner->token = G_TOKEN_NONE;
  scanner->value.v_int = 0;
  scanner->line = 1;
  scanner->position = 0;
  scanner->next_token = G_TOKEN_NONE;
  
  scanner->text = text;
  scanner->text_len = text_len;
  scanner->input_fd = -1;
  scanner->peeked_char = -1;
}

void
g_scanner_add_symbol (GScanner		*scanner,
		      const gchar	*symbol,
		      gpointer		value)
{
  register GScannerHashVal	*hash_val;
  
  g_return_if_fail (symbol != NULL);
  g_return_if_fail (scanner != NULL);
  
  hash_val = g_scanner_lookup_internal (scanner, symbol);
  
  if (!hash_val)
    {
      hash_val = g_new (GScannerHashVal, 1);
      hash_val->key = g_strdup (symbol);
      hash_val->value = value;
      if (!scanner->config->case_sensitive)
	{
	  register guint	i, l;
	  
	  l = strlen (hash_val->key);
	  for (i = 0; i < l; i++)
	    hash_val->key[i] = to_lower (hash_val->key[i]);
	}
      g_hash_table_insert (scanner->symbol_table, hash_val->key, hash_val);
    }
  else
    hash_val->value = value;
}

gpointer
g_scanner_lookup_symbol (GScanner	*scanner,
			 const gchar	*symbol)
{
  register GScannerHashVal	*hash_val;
  
  g_return_val_if_fail (scanner != NULL, NULL);
  
  if (!symbol)
    return NULL;
  
  hash_val = g_scanner_lookup_internal (scanner, symbol);
  
  if (hash_val)
    return hash_val->value;
  else
    return NULL;
}

void
g_scanner_remove_symbol (GScanner	*scanner,
			 const gchar	*symbol)
{
  register GScannerHashVal	*hash_val;
  
  hash_val = g_scanner_lookup_internal (scanner, symbol);
  
  if (hash_val)
    {
      g_hash_table_remove (scanner->symbol_table, hash_val->key);
      g_free (hash_val->key);
      g_free (hash_val);
    }
}

GTokenType
g_scanner_peek_next_token (GScanner	*scanner)
{
  g_return_val_if_fail (scanner != NULL, G_TOKEN_EOF);
  
  if (scanner->next_token == G_TOKEN_NONE)
    {
      scanner->next_line = scanner->line;
      scanner->next_position = scanner->position;
      g_scanner_get_token_i (scanner,
			     &scanner->next_token,
			     &scanner->next_value,
			     &scanner->next_line,
			     &scanner->next_position);
    }
  
  return scanner->next_token;
}

GTokenType
g_scanner_get_next_token (GScanner	*scanner)
{
  g_return_val_if_fail (scanner != NULL, G_TOKEN_EOF);
  
  if (scanner->next_token != G_TOKEN_NONE)
    {
      g_scanner_free_value (&scanner->token, &scanner->value);
      
      scanner->token = scanner->next_token;
      scanner->value = scanner->next_value;
      scanner->line = scanner->next_line;
      scanner->position = scanner->next_position;
      scanner->next_token = G_TOKEN_NONE;
    }
  else
    g_scanner_get_token_i (scanner,
			   &scanner->token,
			   &scanner->value,
			   &scanner->line,
			   &scanner->position);
  
  return scanner->token;
}

GTokenType
g_scanner_cur_token (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, G_TOKEN_EOF);
  
  return scanner->token;
}

GValue
g_scanner_cur_value (GScanner *scanner)
{
  register GValue v;
  
  v.v_int = 0;
  g_return_val_if_fail (scanner != NULL, v);
  
  return scanner->value;
}

guint
g_scanner_cur_line (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, 0);
  
  return scanner->line;
}

guint
g_scanner_cur_position (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, 0);
  
  return scanner->position;
}

gboolean
g_scanner_eof (GScanner	*scanner)
{
  g_return_val_if_fail (scanner != NULL, TRUE);
  
  return scanner->token == G_TOKEN_EOF;
}

static GScannerHashVal*
g_scanner_lookup_internal (GScanner	*scanner,
			   const gchar	*symbol)
{
  register GScannerHashVal	*hash_val;
  
  if (!scanner->config->case_sensitive)
    {
      register gchar *buffer;
      register guint i, l;
      
      l = strlen (symbol);
      buffer = g_new (gchar, l + 1);
      for (i = 0; i < l; i++)
	buffer[i] = to_lower (symbol[i]);
      buffer[i] = 0;
      hash_val = g_hash_table_lookup (scanner->symbol_table, buffer);
      g_free (buffer);
    }
  else
    hash_val = g_hash_table_lookup (scanner->symbol_table, (gchar*) symbol);
  
  return hash_val;
}

static guchar
g_scanner_peek_next_char (GScanner *scanner)
{
  guchar fchar;
  
  if (scanner->text_len)
    {
      fchar = scanner->text[0];
    }
  else if (scanner->input_fd >= 0)
    {
      if (scanner->peeked_char < 0)
	{
	  register gint count;
	  
	  do
	    {
	      count = read (scanner->input_fd, &fchar, 1);
	    }
	  while (count == -1 &&
		 (errno == EINTR ||
		  errno == EAGAIN));
	  
	  if (count != 1)
	    fchar = 0;
	  
	  scanner->peeked_char = fchar;
	}
      else
	fchar = scanner->peeked_char;
    }
  else
    fchar = 0;
  
  return fchar;
}

static guchar
g_scanner_get_char (GScanner	*scanner,
		    guint	*line_p,
		    guint	*position_p)
{
  guchar fchar;
  
  if (scanner->text_len)
    {
      fchar = *(scanner->text++);
      scanner->text_len--;
    }
  else if (scanner->input_fd >= 0)
    {
      if (scanner->peeked_char < 0)
	{
	  register gint count;
	  
	  do
	    {
	      count = read (scanner->input_fd, &fchar, 1);
	    }
	  while (count == -1 &&
		 (errno == EINTR ||
		  errno == EAGAIN));
	  if (count != 1 || fchar == 0)
	    {
	      fchar = 0;
	      scanner->peeked_char = 0;
	    }
	}
      else
	{
	  fchar = scanner->peeked_char;
	  if (fchar)
	    scanner->peeked_char = -1;
	}
    }
  else
    fchar = 0;
  
  if (fchar == '\n')
    {
      (*position_p) = 0;
      (*line_p)++;
    }
  else if (fchar)
    {
      (*position_p)++;
    }
  
  return fchar;
}

static void
g_scanner_free_value (GTokenType     *token_p,
		      GValue	     *value_p)
{
  switch (*token_p)
    {
    case  G_TOKEN_STRING:
    case  G_TOKEN_IDENTIFIER:
    case  G_TOKEN_IDENTIFIER_NULL:
    case  G_TOKEN_COMMENT_SINGLE:
    case  G_TOKEN_COMMENT_MULTI:
      g_free (value_p->v_string);
      break;
      
    default:
      break;
    }
  
  *token_p = G_TOKEN_NONE;
}

static void
g_scanner_get_token_i (GScanner	*scanner,
		       GTokenType	*token_p,
		       GValue		*value_p,
		       guint		*line_p,
		       guint		*position_p)
{
  do
    {
      g_scanner_free_value (token_p, value_p);
      g_scanner_get_token_ll (scanner, token_p, value_p, line_p, position_p);
    }
  while (((*token_p > 0 && *token_p < 256) &&
	  strchr (scanner->config->cset_skip_characters, *token_p)) ||
	 (*token_p == G_TOKEN_CHAR &&
	  strchr (scanner->config->cset_skip_characters, value_p->v_char)) ||
	 (*token_p == G_TOKEN_COMMENT_MULTI &&
	  scanner->config->skip_comment_multi) ||
	 (*token_p == G_TOKEN_COMMENT_SINGLE &&
	  scanner->config->skip_comment_single));
  
  switch (*token_p)
    {
    case	G_TOKEN_IDENTIFIER:
      if (scanner->config->identifier_2_string)
	*token_p = G_TOKEN_STRING;
      break;
      
    case	G_TOKEN_SYMBOL:
      if (scanner->config->symbol_2_token)
	*token_p = (GTokenType) value_p->v_symbol;
      break;
      
    case	G_TOKEN_BINARY:
    case	G_TOKEN_OCTAL:
    case	G_TOKEN_HEX:
      if (scanner->config->numbers_2_int)
	*token_p = G_TOKEN_INT;
      break;
      
    default:
      break;
    }
  
  if (*token_p == G_TOKEN_INT &&
      scanner->config->int_2_float)
    {
      *token_p = G_TOKEN_FLOAT;
      value_p->v_float = value_p->v_int;
    }
  
  errno = 0;
}

static void
g_scanner_get_token_ll	(GScanner	*scanner,
			 GTokenType	*token_p,
			 GValue		*value_p,
			 guint		*line_p,
			 guint		*position_p)
{
  register GScannerConfig	*config;
  register gboolean		in_comment_multi;
  register gboolean		in_comment_single;
  register gboolean		in_string_sq;
  register gboolean		in_string_dq;
  static   guchar		ch;
  register GTokenType		token;
  register GValue		value;
  register GString		*gstring;
  
  config = scanner->config;
  (*value_p).v_int = 0;
  
  if (scanner->token == G_TOKEN_EOF ||
      (!scanner->text_len &&
       (scanner->input_fd < 0 ||
	scanner->peeked_char == 0)))
    {
      *token_p = G_TOKEN_EOF;
      return;
    }
  
  in_comment_multi = FALSE;
  in_comment_single = FALSE;
  in_string_sq = FALSE;
  in_string_dq = FALSE;
  gstring = NULL;
  
  do
    {
      ch = g_scanner_get_char (scanner, line_p, position_p);
      
      value.v_int = 0;
      token = G_TOKEN_NONE;
      
      /* this is *evil*, but needed ;(
       * we first check for identifier first character, because	 it
       * might interfere with other key chars like slashes or numbers
       */
      if (config->scan_identifier &&
	  ch && strchr (config->cset_identifier_first, ch))
	goto identifier_precedence;
      
      switch (ch)
	{
	  register gboolean	in_number;
	  static	 gchar		*endptr;
	  
	case  0:
	  token = G_TOKEN_EOF;
	  (*position_p)++;
	  ch = 0;
	  break;
	  
	case  '/':
	  if (!config->scan_comment_multi ||
	      g_scanner_peek_next_char (scanner) != '*')
	    goto default_case;
	  g_scanner_get_char (scanner, line_p, position_p);
	  token = G_TOKEN_COMMENT_MULTI;
	  in_comment_multi = TRUE;
	  gstring = g_string_new ("");
	  while ((ch = g_scanner_get_char (scanner, line_p, position_p)) != 0)
	    {
	      if (ch == '*' && g_scanner_peek_next_char (scanner) == '/')
		{
		  g_scanner_get_char (scanner, line_p, position_p);
		  in_comment_multi = FALSE;
		  break;
		}
	      else
		gstring = g_string_append_c (gstring, ch);
	    }
	  ch = 0;
	  break;
	  
	case  '\'':
	  if (!config->scan_string_sq)
	    goto default_case;
	  token = G_TOKEN_STRING;
	  in_string_sq = TRUE;
	  gstring = g_string_new ("");
	  while ((ch = g_scanner_get_char (scanner, line_p, position_p)) != 0)
	    {
	      if (ch == '\'')
		{
		  in_string_sq = FALSE;
		  break;
		}
	      else
		gstring = g_string_append_c (gstring, ch);
	    }
	  ch = 0;
	  break;
	  
	case  '"':
	  if (!config->scan_string_dq)
	    goto default_case;
	  token = G_TOKEN_STRING;
	  in_string_dq = TRUE;
	  gstring = g_string_new ("");
	  while ((ch = g_scanner_get_char (scanner, line_p, position_p)) != 0)
	    {
	      if (ch == '"')
		{
		  in_string_dq = FALSE;
		  break;
		}
	      else
		{
		  if (ch == '\\')
		    {
		      ch = g_scanner_get_char (scanner, line_p, position_p);
		      switch (ch)
			{
			  register guint	i;
			  register guint	fchar;
			  
			case  0:
			  break;
			  
			case  '\\':
			  gstring = g_string_append_c (gstring, '\\');
			  break;
			  
			case  'n':
			  gstring = g_string_append_c (gstring, '\n');
			  break;
			  
			case  't':
			  gstring = g_string_append_c (gstring, '\t');
			  break;
			  
			case  'r':
			  gstring = g_string_append_c (gstring, '\r');
			  break;
			  
			case  'b':
			  gstring = g_string_append_c (gstring, '\b');
			  break;
			  
			case  'f':
			  gstring = g_string_append_c (gstring, '\f');
			  break;
			  
			case  '0':
			case  '1':
			case  '2':
			case  '3':
			case  '4':
			case  '5':
			case  '6':
			case  '7':
			  i = ch - '0';
			  fchar = g_scanner_peek_next_char (scanner);
			  if (fchar >= '0' && fchar <= '7')
			    {
			      ch = g_scanner_get_char (scanner, line_p, position_p);
			      i= i * 8 + ch - '0';
			      fchar = g_scanner_peek_next_char (scanner);
			      if (fchar >= '0' && fchar <= '7')
				{
				  ch = g_scanner_get_char (scanner, line_p, position_p);
				  i = i * 8 + ch - '0';
				}
			    }
			  gstring = g_string_append_c (gstring, i);
			  break;
			  
			default:
			  gstring = g_string_append_c (gstring, ch);
			  break;
			}
		    }
		  else
		    gstring = g_string_append_c (gstring, ch);
		}
	    }
	  ch = 0;
	  break;
	  
	case  '.':
	  if (!config->scan_float)
	    goto default_case;
	  token = G_TOKEN_FLOAT;
	  ch = g_scanner_get_char (scanner, line_p, position_p);
	  goto number_parsing;
	  
	case  '$':
	  if (!config->scan_hex_dollar)
	    goto default_case;
	  token = G_TOKEN_HEX;
	  ch = g_scanner_get_char (scanner, line_p, position_p);
	  goto number_parsing;
	  
	case  '0':
	  if (config->scan_octal)
	    token = G_TOKEN_OCTAL;
	  else
	    token = G_TOKEN_INT;
	  ch = g_scanner_peek_next_char (scanner);
	  if (config->scan_hex && (ch == 'x' || ch == 'X'))
	    {
	      token = G_TOKEN_HEX;
	      g_scanner_get_char (scanner, line_p, position_p);
	      ch = g_scanner_get_char (scanner, line_p, position_p);
	      if (ch == 0)
		{
		  token = G_TOKEN_ERROR;
		  value.v_error = G_ERR_UNEXP_EOF;
		  (*position_p)++;
		  break;
		}
	      if (g_scanner_char_2_num (ch, 16) < 0)
		{
		  token = G_TOKEN_ERROR;
		  value.v_error = G_ERR_DIGIT_RADIX;
		  ch = 0;
		  break;
		}
	    }
	  else if (config->scan_binary && (ch == 'b' || ch == 'B'))
	    {
	      token = G_TOKEN_BINARY;
	      g_scanner_get_char (scanner, line_p, position_p);
	      ch = g_scanner_get_char (scanner, line_p, position_p);
	      if (ch == 0)
		{
		  token = G_TOKEN_ERROR;
		  value.v_error = G_ERR_UNEXP_EOF;
		  (*position_p)++;
		  break;
		}
	      if (g_scanner_char_2_num (ch, 10) < 0)
		{
		  token = G_TOKEN_ERROR;
		  value.v_error = G_ERR_NON_DIGIT_IN_CONST;
		  ch = 0;
		  break;
		}
	    }
	  else
	    ch = '0';
	  /* fall through */
	case  '1':
	case  '2':
	case  '3':
	case  '4':
	case  '5':
	case  '6':
	case  '7':
	case  '8':
	case  '9':
	number_parsing:
	if (token == G_TOKEN_NONE)
	  token = G_TOKEN_INT;
	
	gstring = g_string_new ("");
	gstring = g_string_append_c (gstring, ch);
	in_number = TRUE;
	while (in_number)
	  {
	    register gboolean is_E;
	    
	    is_E = (ch == 'e' || ch == 'E') && token == G_TOKEN_FLOAT;
	    ch = g_scanner_peek_next_char (scanner);
	    
	    if (g_scanner_char_2_num (ch, 36) >= 0 ||
		(config->scan_float && ch == '.') ||
		(is_E && ch == '+') ||
		(is_E && ch == '-') )
	      ch = g_scanner_get_char (scanner, line_p, position_p);
	    else
	      in_number = FALSE;
	    
	    if (in_number)
	      switch (ch)
		{
		case  '.':
		  if (token != G_TOKEN_INT &&
		      token != G_TOKEN_OCTAL)
		    {
		      token = G_TOKEN_ERROR;
		      if (token == G_TOKEN_FLOAT)
			value.v_error = G_ERR_FLOAT_MALFORMED;
		      else
			value.v_error = G_ERR_FLOAT_RADIX;
		      in_number = FALSE;
		    }
		  else
		    {
		      token = G_TOKEN_FLOAT;
		      gstring = g_string_append_c (gstring, ch);
		    }
		  break;
		  
		case	'0':
		case  '1':
		case  '2':
		case  '3':
		case  '4':
		case  '5':
		case  '6':
		case  '7':
		case  '8':
		case  '9':
		  gstring = g_string_append_c (gstring, ch);
		  break;
		  
		case	'-':
		case	'+':
		  if (token != G_TOKEN_FLOAT)
		    {
		      token = G_TOKEN_ERROR;
		      value.v_error = G_ERR_NON_DIGIT_IN_CONST;
		      in_number = FALSE;
		    }
		  else
		    gstring = g_string_append_c (gstring, ch);
		  break;
		  
		case	'e':
		case	'E':
		  if ((token != G_TOKEN_HEX && !config->scan_float) ||
		      (token != G_TOKEN_HEX &&
		       token != G_TOKEN_OCTAL &&
		       token != G_TOKEN_FLOAT &&
		       token != G_TOKEN_INT))
		    {
		      token = G_TOKEN_ERROR;
		      value.v_error = G_ERR_NON_DIGIT_IN_CONST;
		      in_number = FALSE;
		    }
		  else
		    {
		      if (token != G_TOKEN_HEX)
			token = G_TOKEN_FLOAT;
		      gstring = g_string_append_c (gstring, ch);
		    }
		  break;
		  
		default:
		  if (token != G_TOKEN_HEX)
		    {
		      token = G_TOKEN_ERROR;
		      value.v_error = G_ERR_NON_DIGIT_IN_CONST;
		      in_number = FALSE;
		    }
		  else
		    gstring = g_string_append_c (gstring, ch);
		  break;
		}
	  }
	endptr = NULL;
	switch (token)
	  {
	  case	G_TOKEN_BINARY:
	    value.v_binary = strtoul (gstring->str, &endptr, 2);
	    break;
	    
	  case	G_TOKEN_OCTAL:
	    value.v_octal = strtoul (gstring->str, &endptr, 8);
	    break;
	    
	  case	G_TOKEN_INT:
	    value.v_int = strtoul (gstring->str, &endptr, 10);
	    break;
	    
	  case	G_TOKEN_FLOAT:
	    value.v_float = g_strtod (gstring->str, &endptr);
	    break;
	    
	  case	G_TOKEN_HEX:
	    value.v_hex = strtoul (gstring->str, &endptr, 16);
	    break;
	    
	  default:
	    break;
	  }
	if (endptr && *endptr)
	  {
	    token = G_TOKEN_ERROR;
	    if (*endptr == 'e' || *endptr == 'E')
	      value.v_error = G_ERR_NON_DIGIT_IN_CONST;
	    else
	      value.v_error = G_ERR_DIGIT_RADIX;
	  }
	g_string_free (gstring, TRUE);
	gstring = NULL;
	ch = 0;
	break;
	
	default:
	default_case:
	if (config->cpair_comment_single &&
	    ch == config->cpair_comment_single[0])
	  {
	    token = G_TOKEN_COMMENT_SINGLE;
	    in_comment_single = TRUE;
	    gstring = g_string_new ("");
	    while ((ch = g_scanner_get_char (scanner,
					     line_p,
					     position_p)) != 0)
	      {
		if (ch == config->cpair_comment_single[1])
		  {
		    in_comment_single = FALSE;
		    ch = 0;
		    break;
		  }
		
		gstring = g_string_append_c (gstring, ch);
		ch = 0;
	      }
	  }
	else if (config->scan_identifier && ch &&
		 strchr (config->cset_identifier_first, ch))
	  {
	  identifier_precedence:
	    
	    if (config->cset_identifier_nth && ch &&
		strchr (config->cset_identifier_nth,
			g_scanner_peek_next_char (scanner)))
	      {
		token = G_TOKEN_IDENTIFIER;
		gstring = g_string_new ("");
		gstring = g_string_append_c (gstring, ch);
		do
		  {
		    ch = g_scanner_get_char (scanner, line_p, position_p);
		    gstring = g_string_append_c (gstring, ch);
		    ch = g_scanner_peek_next_char (scanner);
		  }
		while (ch && strchr (config->cset_identifier_nth, ch));
		ch = 0;
	      }
	    else if (config->scan_identifier_1char)
	      {
		token = G_TOKEN_IDENTIFIER;
		value.v_identifier = g_new0 (gchar, 2);
		value.v_identifier[0] = ch;
		ch = 0;
	      }
	  }
	if (ch)
	  {
	    if (config->char_2_token)
	      token = ch;
	    else
	      {
		token = G_TOKEN_CHAR;
		value.v_char = ch;
	      }
	    ch = 0;
	  }
	break;
	}
      g_assert (ch == 0 && token != G_TOKEN_NONE);
    }
  while (ch != 0);
  
  if (in_comment_multi ||
      in_comment_single ||
      in_string_sq ||
      in_string_dq)
    {
      token = G_TOKEN_ERROR;
      if (gstring)
	{
	  g_string_free (gstring, TRUE);
	  gstring = NULL;
	}
      (*position_p)++;
      if (in_comment_multi || in_comment_single)
	value.v_error = G_ERR_UNEXP_EOF_IN_COMMENT;
      else if (in_string_sq || in_string_dq)
	value.v_error = G_ERR_UNEXP_EOF_IN_STRING;
    }
  
  if (gstring)
    {
      value.v_string = gstring->str;
      g_string_free (gstring, FALSE);
      gstring = NULL;
    }
  
  if (token == G_TOKEN_IDENTIFIER &&
      config->scan_symbols)
    {
      register GScannerHashVal	*hash_val;
      
      hash_val = g_scanner_lookup_internal (scanner, value.v_identifier);
      
      if (hash_val)
	{
	  g_free (value.v_identifier);
	  token = G_TOKEN_SYMBOL;
	  value.v_symbol = hash_val->value;
	}
    }

  if (token == G_TOKEN_IDENTIFIER &&
      config->scan_identifier_NULL &&
      strlen (value.v_identifier) == 4)
    {
      gchar *null_upper = "NULL";
      gchar *null_lower = "null";
      
      if (scanner->config->case_sensitive)
	{
	  if (value.v_identifier[0] == null_upper[0] &&
	      value.v_identifier[1] == null_upper[1] &&
	      value.v_identifier[2] == null_upper[2] &&
	      value.v_identifier[3] == null_upper[3])
	    token = G_TOKEN_IDENTIFIER_NULL;
	}
      else
	{
	  if ((value.v_identifier[0] == null_upper[0] ||
	       value.v_identifier[0] == null_lower[0]) &&
	      (value.v_identifier[1] == null_upper[1] ||
	       value.v_identifier[1] == null_lower[1]) &&
	      (value.v_identifier[2] == null_upper[2] ||
	       value.v_identifier[2] == null_lower[2]) &&
	      (value.v_identifier[3] == null_upper[3] ||
	       value.v_identifier[3] == null_lower[3]))
	    token = G_TOKEN_IDENTIFIER_NULL;
	}
    }
  
  *token_p = token;
  *value_p = value;
}