# include "y2.h"     
# include <string.h> 
# include <ctype.h>  

extern int peekline; /* number of '\n' seen in lookahead */

int gettok( )
{
  register i,
           base;
  register c,
           match,
           reserve;

  begin : reserve = 0;
  lineno          += peekline;
  peekline        = 0;
  c               = unix_getc( finput );
  while ( c == ' ' || c == '\n' || c == '\t' || c == '\f' || c == '\r' )
    {
      if ( c == '\n' )
        ++lineno;
      c = unix_getc( finput );
    }
  if ( c == '/' )
    {
      /* skip comment */
      lineno += skipcom( );
      goto begin;
    }

  switch ( c )
    {

      case -1 :         /* EOF */
        return ( ENDFILE );
      case '{' :
        yacc_ungetc( c );
        return ( '=' ); /* action ... */
      case '<' :        /* get, and look up, a type name (union member name) */
        i     = 0;
        while ( ( c = unix_getc( finput ) ) != '>' &&
                c >= 0 &&
                c != '\n' )
          {
            tokname[ i ] = c;
            if ( ++i >= NAMESIZE )
              --i;
          }
        if ( c != '>' )
          error( "unterminated < ... > clause" );
        tokname[ i ] = '\0';
        for ( i = 1; i <= ntypes; ++i )
          {
            if ( !strcmp( typeset[ i ], tokname ) )
              {
                numbval = i;
                return ( TYPENAME );
              }
          }
        typeset[ numbval = ++ntypes ] = cstash( tokname );
        return ( TYPENAME );

      case '"' :
      case '\'' :
        match = c;
        tokname[ 0 ] = ' ';
        i     = 1;
        for ( ; ; )
          {
            c = unix_getc( finput );
            if ( c == '\n' || c == EOF )
              error( "illegal or missing ' or \"" );
            if ( c == '\\' )
              {
                c = unix_getc( finput );
                tokname[ i ] = '\\';
                if ( ++i >= NAMESIZE )
                  --i;
              }
            else
              if ( c == match )
                break ;
            tokname[ i ] = c;
            if ( ++i >= NAMESIZE )
              --i;
          }
        break ;

      case '%' :
      case '\\' :

        switch ( c = unix_getc( finput ) )
          {

            case '0' :
              return ( TERM );
            case '<' :
              return ( LEFT );
            case '2' :
              return ( BINARY );
            case '>' :
              return ( RIGHT );
            case '%' :
            case '\\' :
              return ( MARK );
            case '=' :
              return ( PREC );
            case '{' :
              return ( LCURLY );
            default :
              reserve = 1;
          }

      default :

        if ( isdigit( c ) )
          {
            /* number */
            numbval = c - '0';
            base    = ( c == '0' ) ? 8 : 10;
            for ( c = unix_getc( finput );
                  isdigit( c );\
                  c = getc( finput ) )
              {
                numbval = numbval * base + c - '0';
              }
            yacc_ungetc( c );
            return ( NUMBER );
          }
        else
          if ( islower( c ) ||\
               isupper( c ) ||\
               c == '_' ||\
               c == '.' ||\
               c == '$' )
            {
              i = 0;
              while ( islower( c ) ||\
                      isupper( c ) ||\
                      isdigit( c ) ||\
                      c == '_' ||\
                      c == '.' ||\
                      c == '$' )
                {
                  tokname[ i ] = c;
                  if ( reserve && isupper( c ) )
                    tokname[ i ] += 'a' - 'A';
                  if ( ++i >= NAMESIZE )
                    --i;
                  c = unix_getc( finput );
                }
            }
          else
            return ( c );

        yacc_ungetc( c );
    }

  tokname[ i ]    = '\0';

  if ( reserve )
    {
      /* find a reserved word */
      if ( !strcmp( tokname, "term" ) )
        return ( TERM );
      if ( !strcmp( tokname, "token" ) )
        return ( TERM );
      if ( !strcmp( tokname, "left" ) )
        return ( LEFT );
      if ( !strcmp( tokname, "nonassoc" ) )
        return ( BINARY );
      if ( !strcmp( tokname, "binary" ) )
        return ( BINARY );
      if ( !strcmp( tokname, "right" ) )
        return ( RIGHT );
      if ( !strcmp( tokname, "prec" ) )
        return ( PREC );
      if ( !strcmp( tokname, "start" ) )
        return ( START );
      if ( !strcmp( tokname, "type" ) )
        return ( TYPEDEF );
      if ( !strcmp( tokname, "union" ) )
        return ( UNION );
      error( "invalid escape, or illegal reserved word: %s", tokname );
    }

    /* look ahead to distinguish IDENTIFIER from C_IDENTIFIER */

  c               = unix_getc( finput );
  while ( c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '/' )
    {
      if ( c == '\n' )
        ++peekline;
      else
        if ( c == '/' )
          {
            /* look for comments */
            peekline += skipcom( );
          }
      c = unix_getc( finput );
    }
  if ( c == ':' )
    return ( C_IDENTIFIER );
  yacc_ungetc( c );
  return ( IDENTIFIER );
}