%{/* scan.l: the (f)lex description file for the scanner. *//*  This file is part of bc written for MINIX.    Copyright (C) 1991, 1992 Free Software Foundation, Inc.    This program is free software; you can redistribute it and/or modify    it under the terms of the GNU General Public License as published by    the Free Software Foundation; either version 2 of the License , or    (at your option) any later version.    This program 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 General Public License for more details.    You should have received a copy of the GNU General Public License    along with this program; see the file COPYING.  If not, write to    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.    You may contact the author by:       e-mail:  phil@cs.wwu.edu      us-mail:  Philip A. Nelson                Computer Science Department, 9062                Western Washington University                Bellingham, WA 98226-9062       *************************************************************************/#include "bcdefs.h"#include "y.tab.h"#include "global.h"#include "proto.h"/* Using flex, we can ask for a smaller input buffer.  With lex, this   does nothing! */#ifdef SMALL_BUF#undef YY_READ_BUF_SIZE#define YY_READ_BUF_SIZE 512#endif/* We want to define our own yywrap. */#undef yywrap_PROTOTYPE(int yywrap, (void));/* MINIX returns from read with < 0 if SIGINT is  encountered.   In flex, we can redefine YY_INPUT to the following.  In lex, this   does nothing! */#include <errno.h>#undef  YY_INPUT#define YY_INPUT(buf,result,max_size) \	while ( (result = read( fileno(yyin), (char *) buf, max_size )) < 0 ) \	    if (errno != EINTR) \		YY_FATAL_ERROR( "read() in flex scanner failed" );%}DIGIT [0-9A-F]LETTER [a-z]%%define return(Define);break  return(Break);quit   return(Quit);length return(Length);return return(Return);for    return(For);if     return(If);while  return(While);sqrt   return(Sqrt);scale  return(Scale);ibase  return(Ibase);obase  return(Obase);auto   return(Auto);else   return(Else);read   return(Read);halt   return(Halt);last   return(Last);warranty return(Warranty);continue return(Continue);print  return(Print);limits return(Limits);"+"|"-"|";"|"("|")"|"{"|"}"|"["|"]"|","|"^" { yylval.c_value = yytext[0]; 					      return((int)yytext[0]); }&& { return(AND); }\|\| { return(OR); }"!" { return(NOT); }"*"|"/"|"%" { yylval.c_value = yytext[0]; return(MUL_OP); }"="|\+=|-=|\*=|\/=|%=|\^=  { yylval.c_value = yytext[0]; return(ASSIGN_OP); }=\+|=-|=\*|=\/|=%|=\^  { #ifdef OLD_EQ_OP			 char warn_save;			 warn_save = warn_not_std;			 warn_not_std = TRUE;			 warn ("Old fashioned =<op>");			 warn_not_std = warn_save;			 yylval.c_value = yytext[1];#else			 yylval.c_value = '=';			 yyless (1);#endif			 return(ASSIGN_OP);		       }==|\<=|\>=|\!=|"<"|">" { yylval.s_value = strcopyof(yytext); return(REL_OP); }\+\+|-- { yylval.c_value = yytext[0]; return(INCR_DECR); }"\n" { line_no++; return(NEWLINE); }\\\n {  line_no++;  /* ignore a "quoted" newline */ }[ \t]+  { /* ignore spaces and tabs */ }"/*"  {	int c;	for (;;)	  {	    while ( ((c=input()) != '*') && (c != EOF)) 	      /* eat it */	      if (c == '\n') line_no++;	    if (c == '*') 	      {		while ( (c=input()) == '*') /* eat it*/;		if (c == '/') break; /* at end of comment */		if (c == '\n') line_no++;	      }	    if (c == EOF)	      {		fprintf (stderr,"EOF encountered in a comment.\n");		break;	      }	  }      }[a-z][a-z0-9_]* { yylval.s_value = strcopyof(yytext); return(NAME); }\"[^\"]*\"  { 	      unsigned char *look;	      int count = 0;	      yylval.s_value = strcopyof(yytext);	      for (look = yytext; *look != 0; look++)		{		  if (*look == '\n') line_no++;		  if (*look == '"')  count++;		}	      if (count != 2) yyerror ("NUL character in string.");	      return(STRING);	    }{DIGIT}({DIGIT}|\\\n)*("."({DIGIT}|\\\n)*)?|"."(\\\n)*{DIGIT}({DIGIT}|\\\n)* {	      unsigned char *src, *dst;	      int len;	      /* remove a trailing decimal point. */	      len = strlen(yytext);	      if (yytext[len-1] == '.')	        yytext[len-1] = 0;	      /* remove leading zeros. */	      src = yytext;	      dst = yytext;	      while (*src == '0') src++;	      if (*src == 0) src--;	      /* Copy strings removing the newlines. */	      while (*src != 0)		{	          if (*src == '\\')		    {		      src++; src++;		      line_no++;		    }		  else		    *dst++ = *src++;	        }	      *dst = 0;	      yylval.s_value = strcopyof(yytext); 	      return(NUMBER);	    }.       {	  if (yytext[0] < ' ')	    yyerror ("illegal character: ^%c",yytext[0] + '@');	  else	    if (yytext[0] > '~')	      yyerror ("illegal character: \\%3d", (int) yytext[0]);	    else	      yyerror ("illegal character: %s",yytext);	}%%/* This is the way to get multiple files input into lex. */intyywrap(){  if (!open_new_file ()) return (1);	/* EOF on standard in. */  return (0);				/* We have more input. */}