I have developed a interpreted programming language. It is strongly based on C. The problem is, I want to add a foreach directive and have no clue how to. I am using Bison and Flex as the parser and lexer generator. ...
I wounder how to implement indentation as block delimiters in bison + flex. Just like in python. I'm writing my own programming language ( mostly for fun, but I intend to use it together with a game engine ), I'll try to come up with something special that minimizes boilerplate and maximizes dev speed. I have already written an compiler...
From the Bison Manual: In a simple interactive command parser where each input is one line, it may be sufficient to allow yyparse to return 1 on error and have the caller ignore the rest of the input line when that happens (and then call yyparse again). This is pretty much what I want, but I am having trouble getting to...
Wikipedia's Interpolation Definition I am just learning flex / bison and I am writing my own shell with it. I am trying to figure out a good way to do variable interpolation. My initial approach to this was to have flex scan for something like ~ for my home directory, or $myVar , and then set what the yyval.stringto what is returned u...
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.exe CPP = g++ LEX = flex YACC = bison .PHONY: all clean all: $(OBJECTS) $(CPP) $^ -o $(PROGRAM) clean...
Hello all :) I've been looking to recognise a language which does not fit the general Flex/Bison paradigm. It has completely different token rules depending on semantic context. For example: main() { batchblock { echo Hello World! set batchvar=Something echo %batchvar% } } Bison apparently supports recognition of these ty...
When compiling my project with gcc and the -Wall option, I get a warning about a statement with no effect in the non-existant last line of my flex file: Warning: gcc -Wall -O0 -ggdb3 -DNOSUDO -DJOBC -DDEBUG -c lex.yy.c tokenizer.l: In function ‘yylex’: tokenizer.l:179: warning: statement with no effect Shell Command: $ wc -l tokeniz...
Okay, in my quest to figure out the necessary stuff to write a compiler, I've reached a bit of a roadblock. It seems that every technology or tool that I find has some opposition somewhere. I use Bison and Flex right now but I'm getting the feeling that this method is outdated. Is this true? Is this a good forward-compatible way to p...
Dear Overflowns: I have an executable whose input is contained in an ASCII file with format: $ GENERAL INPUTS $ PARAM1 = 123.456 PARAM2=456,789,101112 PARAM3(1)=123,456,789 PARAM4 = 1234,5678,91011E2 PARAM5(1,2)='STRING','STRING2' $ NEW INSTANCE NEW(1)=.TRUE. PAR1=123 [More data here] $ NEW INSTANCE NEW(2)=.TRUE. [etcetera] In ...
Hello I want to define char (ie 'a AND 'a') but I am having issues in checking errors. Here how I write the rule and check: char " ' " {letter} code {char} { int x =input() ; //printf("%d",'a'); if(x == 10) { return(tCharunterm); } ...
How to call a flex parser in c ? ...
I am storing the arguments passed to main in yacc in a file. Now I want the lex to read its input from this file rather than the terminal. I know I can point yyin to a file like yyin = fopen("fn","r"); but this works only when main is in lex. When I use this yyin declaration in main in yacc, it shows an error so please suggest something...
guyz i need to pass an integer array from lex to yacc.i know v can pass an integer using union of yylval but how to pass an array ...pls help me ...
I'm reading Flex & Bison from O'Reilly, and would like to know if learning Regular Expressions beforehand will help in developing a programming language? ...
I have a simple "language" that I'm using Flex(Lexical Analyzer), it's like this: /* Just like UNIX wc */ %{ int chars = 0; int words = 0; int lines = 0; %} %% [a-zA-Z]+ { words++; chars += strlen(yytext); } \n { chars++; lines++; } . { chars++; } %% int main() { yylex(); printf("%8d%8d%8d\n", lines, words, char...
Hello, I'm building my own language using Flex, but I want to know some things: Why use lexical analyzers? There are going to help me in something? Are they obligatory? Thanks. ...
Suppose I want my Lex and Yacc program to parse the command line arguments like: ./a.out show memory I want lex to parse the string "show memory". How do I accomplish this? ...
i want to parse from a string rather than a file. i know that v can use yy_scan_string fn to do it.but for me it's not working properly so pls help me ...
what libraries should be linked in lex & yacc (solaris) to include YY_BUFFER_STATE. when i use YY_BUFFER_STATE in lex and compile it .i get an error saying tat it is undeclared.but when i do it in unix i am getting the output so pls help me. ...
I wanted to experiment with the Shakespeare programming language, so I downloaded it from here and executed the Makefile using cd spl-1.2.1 Make. The compilation of spl2c executes with a couple warnings: scanner.l:600: warning, rule cannot be matched <stdout>:5808: warning: ‘yyunput’ defined but not used And then when it at...