flex VS Cwerg

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.

Perhaps these have already been dealt with and I'm missing critical information. If so, my apologies. Great work, in any case.

[1] https://github.com/robertmuth/Cwerg/tree/master/FrontEnd#dis...

Cwerg has backend that can be used as JIT and is written with readability in mind. Additional documentation can be found here: https://github.com/robertmuth/Cwerg/tree/master/Docs

I defined a basic ISA-like IR for Cwerg. It has unlimited registers and no constraints on immediates.

entire compiler front end ast nodes

I was also going down the path of bike shedding concrete syntax for my language Cwerg before pulling the plug on that effort and just using s-exprs. I managed to make the s-expr quite succinct by carefully choosing the order of arguments so I can omit optional ones. Also very helpful was to use square brackets for list, e.g. (call fun-name [arg1 arg2]). This simplifies parsing a little bit and is easier on the eye. Here are some Code Examples

I am iterating over the languages features for Cwerg's Frontend which aims to be a low level language with about the complexity of C but with some of the comforts of modern languages. I am especially happy with the choice of adding sum types. Relative to C the current feature set looks like this: Removed: * arrays decay to pointers * bitfields * separate compilation (more of a backend issue) * pre-processor * varargs * implcit type conversions * (untagged) unions * ++/-- * comma operator * implicitly nullable pointers * goto