Hi, I need to tokenize some strings which will be splitted of according to operators like = and !=. I was successful using regex until the string has != operator. In my case, string was seperated into two parts, which is expected but ! mark is in the left side even it is part of given operator. Therefore, I believe that regex is not sui...
I am attempting to parse, not evaluate, rails ERB files in a Hpricot/Nokogiri type manner. The files I am attempting to parse contain HTML fragments intermixed with dynamic content generated using ERB (standard rails view files) I am looking for a library that will not only parse the surrounding content, much the way that Hpricot or No...
When I attempt to compile the output of this trivial lex program: # lex.l integer printf("found keyword INT"); using: $ gcc lex.yy.c I get: Undefined symbols: "_yywrap", referenced from: _yylex in ccMsRtp7.o _input in ccMsRtp7.o "_main", referenced from: start in crt1.10.6.o ld: symbol(s) not found collect2...
I'm totally new to flex. I'm getting a build error when using flex. That is, I've generated a .c file using flex, and, when running it, am getting this error: 1>lextest.obj : error LNK2001: unresolved external symbol "int __cdecl isatty(int)" (?isatty@@YAHH@Z) 1>C:\...\lextest.exe : fatal error LNK1120: 1 unresolved externals here i...
how to parse from command line arguements in yacc ? of course i undefined input in both lex & yacc and then wrote int input(void) { printf("in input\n:"); char c; if(target > limit) return 0; if((c = target[0][offset++]) != '\0') return (c); target++; offset =0; return (' '); } where target contains the command line arguements. But ...
#include<stdio.h> int main() { int a,b; a=a+b; printf("%d",a); return 0; } what should be the output if this code is passed through a lexer ...
hallo, i have a problem, the followed program gives back an error, error:: Undeclared(first use in function), why this error appears all tokens are declared, but this error comes, can anyone help me, here are the lex and yac files.thanks lex: %{ int yylinenu= 1; int yycolno= 1; %} %x STR DIGIT [0-9] ALPHA ...
#include<stdio.h> #include<ctype.h> #include<string.h> /* this is a lexer which recognizes constants , variables ,symbols, identifiers , functions , comments and also header files . It stores the lexemes in 3 different files . One file contains all the headers and the comments . Another file will contain all the variables , another will...
I am experimenting with lex and yacc and have run into a strange issue, but I think it would be best to show you my code before detailing the issue. This is my lexer: %{ #include <stdlib.h> #include <string.h> #include "y.tab.h" void yyerror(char *); %} %% [a-zA-Z]+ { yylval.strV = yytext; return ID; } [0-9]+ { yylval.intV...
i want to parse a command line using a yacc but i want to call it from a c file. how it is possible ? ...
I'm writing a program in lex, and it gives me the following error: scanner.l:49: unrecognized rule Line 49 is: {number} {return(NUM);} EDIT: However, the error seems related to the line directly before that, {id} {return(ID);}. It will list the line directly after that rule as the source of the error, even if it's blank. Here's...
Hi. I'm running a lexical analyzer using lex, and I've got it mostly correct, but my terminal gives strange output once I take out an ECHO statement I was using to help debug the code. With that statement, my output looks like this: max@Max-Ubuntu:~/Desktop/Compiler Project/project2$ ./a.out <../cmmFiles/expression.cmm VOIDID(){ INT...
Hello, I'm developing a small python like language using flex, byacc (for lexical and parsing) and C++, but i have a few questions regarding scope control. just as python it uses white spaces (or tabs) for indentation, not only that but i want to implement index breaking like for instance if you type "break 2" inside a while loop that'...
Do Lex and Yacc provide optimized code or is it required that we write our own code manually for higher performance? ...
For a school project, I need to implement a parser for a (probably XML-based) markup language for User Interfaces. Based on the input it generates a HTML document with various UI components (textareas, inputs, panels, dialogs etc.) Do you have any suggestions for tools/libraries I might use for this? (At school we use Flex and Bison, b...
Anybody knows from where I can download a Lex and Yacc program(the source code) for complete syntax checking of a C program? Pls post the link as comment ...
I need to format some hexdump like this: 00010: 02 03 04 05 00020: 02 03 04 08 00030: 02 03 04 08 00010: 02 03 04 05 00020: 02 03 04 05 02 03 04 05 02 03 04 08 to 02 03 04 05 02 03 04 08 02 03 04 02 03 04 05 02 03 04 05 02 03 04 05 02 03 04 remove the address fields, if present remove any 08 at the end of a paragraph (followed ...
%{ #include "y.tab.h" extern int yylval; %} %% [0-9]+ {yylval = atoi (yytext); return NUM;} [ \t] ; \n return 0; . return yytext[0]; %% When I use yylval which is pointing to the value, why should I return the NUM? I mean what does NUM represent (NUM is decalred in YACC section)? Is NUM storing any val...
I am presently learning Lexical Analysis in Compiler Design. In order to learn how really a lexical analyzer works I am trying to build one myself. I am planning to build it in Java. The input to the lexical analyzer is a .tex file which is of the following format. \begin{document} \chapter{Introduction} \section{Scope} ...
Hi, I am trying to do a sintax text corrector for my compilers' class. The idea is: I have some rules, which are inherent to the language (in my case, Portuguese), like "A valid phrase is SUBJECT VERB ADJECTIVE", as in "Ruby is great". Ok, so first I have to tokenize the input "Ruby is great". So I have a text file "verbs", with a lot ...