bison

I've written an interpreter for a C-like language, using Flex and Bison for the scanner/parser. It's working fine when executing full program files. Now I'm trying implement a REPL in the interpreter for interactive use. I want it to work like the command line interpreters in Ruby or ML: Show a prompt Accept one or more statements on the line If the expression is incomplete display a continuation prompt allow the user to continue entering lines When the line ends with a complete expression echo the result of evaluating the last expression show the main prompt My grammar starts with a top_level

How much time would it take to write a C++ compiler using lex/yacc? Where can I get started with it? There are many parsing rules that cannot be parsed by a bison/yacc parser (for example, distinguishing between a declaration and a function call in some circumstances). Additionally sometimes the interpretation of tokens requires input from the parser, particularly in C++0x. The handling of the character sequence >> for example is crucially dependent on parsing context. Those two tools are very poor choices for parsing C++ and you would have to put in a lot of special cases that escaped the

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 <stdio.h> #include "opcodes.h" #include "utils.h" void yyerror(const char *s) { fprintf(stderr, "error: %s\n", s); } int counter = 0; extern "C" { int yyparse(void); int yylex(void); int

I'm looking for the C grammar in GCC source code, more specifically for the grammar in the yacc/bison form. Found the C grammar in Yacc specification in the GCC version 3.3 in the file "c-parse.y" You will not find a C grammar yacc/bison file within the current GCC source code. It was done in the past, before the egcs fork stuff. I cannot give you the exact version and location, but i can tell you that it should be in the 2.x release The current version of GCC has its own C parser GCC of version 4.3 did not contain explicitly written C grammar. Parsing and semantical analysis were performed

I'm trying to use flex and bison to create a filter, because I want get certain grammar elements from a complex language. My plan is to use flex + bison to recognise the grammar, and dump out the location of elements of interest. (Then use a script to grab text according the locations dumped.) I found flex can support a bison feature called bison-locations, but how it works in exactly. I tried the example in flex document, it seems the yylloc is not set automatically by flex, I always get (1,0)-(1,0) . Could flex calculate each token's location automatically? If not, what interface function is

I'm doing a simple calculator with flex and bison but it only reads the first line of the input file. this is my bison code: %{ #include <stdio.h> #include <stdlib.h> #include <math.h> #include "symtab.h" extern int yylex(void); extern char *yytext; extern int num_linea; extern FILE *yyin; void yyerror(char *s); %} %union{ struct{ char *lexema; int lenght; int line; }ident; } %union{ struct{ int integer; float real; char *string; int type; }num; } %union{ int num_int; } %union{ float num_float; } %token <ident> IDENT %token <num> LIT_INT %token <num> LIT_FLOAT %token <num> CADENA %token