problem about lex-Collection of common programming errors

• 
  Charles Bailey
  c++ yacc bison lex
  I already looked for my answer but I didn’t get any quick response for a simple example.I want to compile a flex/bison scanner+parser using g++ just because I want to use C++ classes to create AST and similar things.Searching over internet I’ve found some exploits, all saying that the only needed thing is to declare some function prototypes using extern “C” in lex file.So my shady.y file is%{ #include #include “opcodes.h” #include “utils.h”void yyerror(const char *s) {fprintf(stderr, “error: %s\
• 
  user2764421
  python parsing calculator lex ply
  I would like to ask for help for an exercise to do a calculator which recognizes the English words and numbers in Python but now using PLY (Python Lex-Yacc)The numbers and the operators can be given in two forms written as a string using English words, “plus” = “+”, “two” = 2, “hundred twelve” = 112, etc… An example could be these entries: “twenty five divided by 5” or “25 / 5” or “twenty five divided by five” the result should be the same, a number 5 (not a string). ” -3 times 4″ will give -12 Division by 0 will give “Error” ” 34 divided by 0″ will give “Error”This should work for several basic operators “-“,”+”,”x” and “/”
• 
  N mol
  c compiler yacc lex
  I am trying to develop a program which converts infix expression to postfix expression using lex and yacc tools. Here is the source code :(Lex program: ipi.l)ALPHA [A-Z a-z]DIGIT [0-9]%%{ALPHA}({ALPHA}|{DIGIT})* return ID;{DIGIT}+ {yylval=atoi(yytext); return ID;}[\n \t]
• 
  Kavya L
  android ubuntu android-emulator lex
  When I run. build/envsetup.sh lunch full-eng makeI get the following errortarget Executable: tcpdump (out/target/product/generic/obj/EXECUTABLES/tcpdump_intermediates/LINKED/tcpdump) p
• 
  lesmana
• 
  Mat
  c linker yacc lex
  hi i recieve the follwing error main.c: undefined reference to yyin main.c: undefined reference to yyparsethis is what i am doing i have a lex file a.l a yacc file b.ymain.c is :#include #include #i
• 
  dstnbrkr
  gcc lex lexer
  When I attempt to compile the output of this trivial lex program:# lex.l integer printf(“found keyword INT”);using:
• 
  user205688
  yacc lex
  how to parse from command line arguements in yacc ?of course i undefined input in both lex & yacc and the
• 
  bias
  arrays gcc lex
  So, copying the code from Introduction to Compiler Construction in Unix I wind up with the snippet:/* samplec.l snipped */ static struct rwtable { /* reserved word table */char *rw_name; /* representation */int rw_yylex; /* yylex() value */} rwtable[] = { /* sorted */”break”, token(BREAK),”continue”, token(CONTINUE),”else”, token(ELSE),”if”,
• 
  lesmana
  linker-error lex flex-lexer
  I apologize if this is a straightforward question, but I’m running into some linker errors with flex when I try compiling the resulting scanner with g++. If I give flex the followi
• 
  lesmana
  c++ c linux lex flex-lexer
  How can I use a scanner I’ve written using Flex as part of a program I’m designing? Specifically, within a c++ class as a method of the class, and from a separate file with just a main method to perform testing.
• 
  alibenmessaoud
  linux ubuntu grammar yacc lex
  I’d like to write down a formal grammar for describing the command line usage of some GNU/Linux tools. First, I would like to define a gra
• 
  Udi
  yacc lex
  I’m new to yacc/lex and I’m working on a parser that was written by som
• 
  lesmana
  c path windows-xp lex flex-lexer
  I’m trying to use flex and have installed in c:\gnuwin32\bin have added such to PATH as well as c:\dev-cpp\bin.Calls to gcc work
• 
  ptwiggerl
  gcc bison yacc lex
  Lex and Yacc work, but when I try to compile the y.tab.c file, I’m getting the following error. I have a feeling its a linking issue where compiler can’t find t
• 
  lesmana
  lex flex-lexer
  I am writing a lex program. The objective of this problem is that I enter a string Exemple Name@Phon
• 
  Nemo
  posix lex
  Say i have some rules and actions, like so, { do something; } \. { do_something; } \(
• 
  Sileno Brito
  c reference makefile yacc lex
  I’m trying to use flex and bison to create a simple calc, but i receive errors when i try compile, i don’t experience in YACC or FLEX this is my first program.flex 2.5.35, bison (GNU bison) 2.3, gcc (Debian 4.3.2-1.1) 4.3.2, linux 2.6.26-1-686this is the error:bison -d -y math.yacc -b math lex -P math math.lex gcc lex.math.c math.tab.c -g -Wall -lfl -ll -o math.parse.so math.tab.c: In function ‘yyparse’: math.tab.c:1244: warning: implicit declaration of function ‘yylex’ /tmp/ccOhwzV0.o: In function `yyparse’: /root/.netbeans/remote/192.168.56.101/silenobrito-nb-Windows-x86_64/D/source/lib- math/src/model/math.tab.c:1244: undefined reference to `yylex’ collect2: ld returned 1 exit statu
• 
  lesmana
  g++ bison lex undefined-reference flex-lexer
  I’m trying to use flex and bison to create a simple scripting language. Right now, I’m just trying to get a calculator working.I can’t get it to compile, though. When I run this makefile:OBJECTS = hug.tab.o hug.yy.o PROGRAM = hug.exeCPP = g++ LEX = flex YACC = bison
• 
  Peter Lang
  c lex
  #include #include #include/* 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 contain all the symbols. */int main() {int i=0,j,k,count=0;char a,b[100],c[10000],d[100];memset ( d, 0, 100 );j=30;FILE *fp1,*fp2;fp1=fopen(“source.txt”,”r”); //the source file is opened in read only mode which will passed through the lexerfp2=fopen(“lext.txt”,”w”);//now lets remove all the white spaces and store the rest of the words in a fileif(fp1==NULL){perror(“failed to open source.txt”);//return EXIT_FAILURE;}i=0;k=0;while(!feof(fp1)){a=fgetc(fp1);if(a!=’ ‘&&a!=’\n’){if (!isalpha(a)){switch(a){case ‘+’:{fprintf(fp2,”+ —-> PLUS \n”);i=0;break;}case ‘-‘:{fprintf(fp2,”- —> MINUS \n”);i=0;break;}case ‘*’:{fprintf(fp2, “* —>MULT \n”);i=0;break;}case ‘/’:{fprintf(fp2, “/ —>DIV \n”);i=0;break;}//case ‘+=’:fprintf(fp2, “%.20s
• 
  Jonathan Leffler
  bison yacc lex flex-lexer
  I’m trying a implement a flex/bison calculator which can do floating point arithmetic. My flex code looks like this%{ #include “calc.tab.h” #include void yyerror(char *s); %}digit [0-9] integer {digit}+ real ({digit}+[.]{digit}*)|({digit}*[.]{digit}+) exp ({integer}|{real})[eE]-?{integer}%%({integer}|{real}|{exp}) { yylval = atof(yytext); return NUMBER; } [-+*/\n] { return *yytext; } [ \t\v\f\r]
• 
  lesmana
  c++ lex flex-lexer flex++
  Note: Someone with over 1500 rep.. please add flex++ and bison++ as tags :).Seems like people all over the Internet have been getting the following errors with Flex++:scanner.l:1: bad character: % scanner.l:1: unknown error processing section 1This happens on any example I give Flex++. The version I have is from here and I have t
• 
  Omnifarious
  c gcc lex
  I am doing the complier project of CS143 of Stanford. It is about implementing a lexical analyzer with the help of flex. Here is the link: https://github.com/dunecn/cs143-pp1I downloaded the source code and wanted to complie the file of scanner.l, it occured

Originally posted 2013-11-09 22:45:43.