flex VS walld

I am using Flex++, which is Flex for C++ and I am having trouble setting the input file. Flex++ uses the FlexLexer class provided in FlexLexer.h to create the lexer object(https://github.com/westes/flex/blob/master/src/FlexLexer.h). In my main function I have

Further applications of DFA and NFA: lex or flex, yacc or bison, and POE :-)

How about writing a programming language using Flex and Bison? There are lots of good tutorials and examples out there.

Some lexer generators (notably Flex) take input from a file handle by default. While you can always read a file into a string before passing it to the generated lexer, this is not seen as "the best" since you have to read in all the data into memory, which can be a lot.

Ages ago, I loved writing domain-specific toy languages, and almost always used flex to generate lexers and GNU bison to generate the parser. I've begun a new toy project and I don't think those two will cut it this time, so I'm looking for other tools that integrate well with C++.

I don't understand :c don't lexers like Flex work off of regex rules? Isn't this the correct first step to parse it?

I wrote a C compiler using flex [1] and bison [2]. The glue between them is a bit hacky.

At some point ANTLR [3] looked promising, but these days I'd probably write a lexer and recursive descent parser by hand, then generate LLVM IR.

[1] https://github.com/westes/flex

github.com/westes/flex/releases

Un commento in flex, uno storico software, tanto per mostrare che anche i migliori fanno le cose alla buona.