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%{
/* scan.l: the (f)lex description file for the scanner. */
/* This file is part of bc written for MINIX.
Copyright (C) 1991, 1992, 1993, 1994 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);
"." {
#ifdef DOT_IS_LAST
return(Last);
#else
yyerror ("illegal character: %s",yytext);
#endif
}
"+"|"-"|";"|"("|")"|"{"|"}"|"["|"]"|","|"^" { 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. */
int
yywrap()
{
if (!open_new_file ()) return (1); /* EOF on standard in. */
return (0); /* We have more input. */
}
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