I have some bison grammar: input: /* empty */ | input command ; command: builtin | external ; builtin: CD { printf("Changing to home directory...\n"); } | CD WORD { printf("Changing to directory %s\n", $2); } ; I'm wondering how I get Bison to not accept (YYACCEPT?) something as a command until...
Hello, I have a scientific application for which I want to input initial values at runtime. I have an option to get them from the command line, or to get them from an input file. Either of these options are input to a generic parser that uses strtod to return a linked list of initial values for each simulation run. I either use the co...
Hallo Rudi, I dont get the error, please can you help me out, here is the .l and .y file.thanks. %{ #include "ifanw.tab.h" extern int yylval; %} %% "=" { return EQ; } "!=" { return NE; } "<" { return LT; } "<=" { return LE; } ">" { return GT; } ">=" { return GE; } "+" { return PLUS; } "-" { return MI...
I'm writing a calculator with an ability to accept new function definitions. Being aware of the need of newbies to try recursive functions such as Fibonacci, I would like my calculator to be able to recognize Tail-recursive functions with Flex + Bison and convert code to an Iterative form. I'm using Flex & Bison to do the job. If you hav...
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 ...
Hi there .. i'm using GNU Bison 2.4.2 to write a grammar for a new language i'm working on and i have a question. When i specify a rule, let's say : statement : T_CLASS T_IDENT '{' T_CLASS_MEMBERS '}' { // create a node for the statement ... } If i have a variation on the rule, for instance statement : T_CLASS T_IDENT T_E...
Is there a way to force bison and/or flex to restart scanning after I replace some token with something else? My particular example would be with replacement for a specific word/string. If I want a word of hello to be replaced by echo hello, how can I get flex or bison to replace hello and then start parsing again (to pick up 2 words i...
Hi Is there any existing tool to strip all the action code from bison grammar files, leaving only the {} around it? ...
Hallo everybody, Can someone help me out of my situation, im searching for a instrucior that implements the JMP (Jump) instructior like in Assembler. I've found out that it could be withe the goto function of Flex/Bison but i have no really idea how to do. Have got anyone idea. Im very grateful of yours help. Thanks. Here is an example ...
I'm looking for the C grammar in GCC source code, more specifically for the grammar in the yacc/bison form. ...
I compiled my bison-generated files in Visual Studio and got these errors: ...\position.hh(83): error C2589: '(' : illegal token on right side of '::' ...\position.hh(83): error C2059: syntax error : '::' ...\position.hh(83): error C2589: '(' : illegal token on right side of '::' ...\position.hh(83): error C2059: syntax error :...
I'm using bison & flex (downloaded via cygwin) with vc++. When I compile the program I got an error: ...: fatal error C1083: Cannot open include file: 'unistd.h': No such file or directory The corresponding code in the flex-generated file is: #ifndef YY_NO_UNISTD_H /* Special case for "unistd.h", since it is non-ANSI. We include it w...
Hallo, I need help in Lex/Yacc Programming. I wrote a compiler for a syntactical analysis for inputs of many statements. Now i have a special problem. In case of an Input the compiler gives the right output, which statement is uses, constant operator or a jmp instructor to which label, now i have to write so, if now a if statement com...
Hy guys, i'm developing a scripting engine with flex and bison and now i'm implementing the eval and load functions for this language. Just to give you an example, the syntax is like : import std.*; load( "some_script.hy" ); eval( "foo = 123;" ); println( foo ); So, in my lexer i've implemented the function : void hyb_parse_string...
Hi All, I am very new to Flex/Bison, So it is very navie question. Pardon me if so. May look like homework question - but I need to implement project based on below concept. My question is related to two parts, Question 1 In Bison parser, How do I provide rules for optional input. Like, I need to parse the statment Example : ...
I need some help in bison grammar construction. From my another question: I'm trying to make a meta-language for writing markup code (such as xml and html) wich can be directly embedded into C/C++ code. Here is a simple sample written in this language, I call it WDI (Web Development Interface): /* * Simple wdi/html sample source cod...
I've never done Bison or Wisent before. how can I get started? My real goal is to produce a working Wisent/Semantic grammar for C#, to allow C# to be edited in emacs with code-completion, and all the other CEDET goodies. (For those who don't know, Wisent is a emacs-lisp port of GNU Bison, which is included into CEDET. The Wisent appar...
Hey, I would like to create simple C++ calculator using bison and flex. Please note I'm new to the creating parsers. I already found few examples in bison/flex but they were all written in C. My goal is to create C++ code, where classes would contain nodes of values, operations, funcs - to create AST (evaluation would be done just afte...
Hello there: Do you folks know of any GNU/Linux utility to format a Bison grammar file, containing C code, nicely? I'm thinking of something along the lines of GNU Indent, but designed to beautify grammar files rather than C code. ...
I would like to write myself a pretty printer for java using bison and flex. I have written a pretty printer for a script language, but I was only writing visitors, which made the printing. How can I turn a program using my formal grammar into a tree of nodes (made using C++ classes), that afterwards I could visit using my visitor? Maybe...