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Diffstat (limited to 'gnu/usr.bin/bc/scan.l')
| -rw-r--r-- | gnu/usr.bin/bc/scan.l | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/gnu/usr.bin/bc/scan.l b/gnu/usr.bin/bc/scan.l new file mode 100644 index 0000000..8189364 --- /dev/null +++ b/gnu/usr.bin/bc/scan.l @@ -0,0 +1,196 @@ +%{ +/* 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. */ +} |
