rust-peg VS dmd

And some related parser tools: - https://github.com/kevinmehall/rust-peg - https://github.com/pest-parser/pest - https://github.com/lalrpop/lalrpop

Rust is a very nice langage for implementing compilers, and has a nice ecosystem for it (logos, rust-peg, lalrpop, astmaker -- this one is mine --, etc...).

My peg crate is a parser generator that supports arbitrary token types as input. See https://github.com/kevinmehall/rust-peg/blob/master/tests/run-pass/tokens.rs for an example.

The one rust parser-generator I used is PEG

The two parser generators that I am aware of are lalrpop and PEG. There both great, and have seen some use by languages that have been written in Rust.

rust-peg

I wanted to create a parser for Apertium Stream. In 2014, I used Whittle in Ruby. If this year were 2001, I would use Lex/Yacc. Anyway, this year is 2021. I wanted to create this parser in Rust. I tried to find what is similar to Lex/Yacc. I found Rust-Peg. I found a link to Nom from Rust-Peg's document. My first impression was Nom example is easy to read. At least, its document claimed Nom is fast.

The peg crate has a resolved issue about this.

I don't really know that much about parsing and grammars, other than what I've learned about regular languages and expressions and context-free languages in a standard Theory of Comp course from my university. I basically just learned peg by reading the Wikipedia article on PEGs, reading the crate documentation to understand the syntax, and then looking at some of the peg examples on their GitHub to understand how it works in practice.

Here's the pipeline spitting out the same error as on my macbook did.

https://github.com/dlang/dmd/actions/runs/8023469412/job/219...

Not completely on topic (if you read TFA) but my favorite Git commit is by compiler badass and HN frequenter, where he checks in an entire C compiler to the D language repo:

https://github.com/dlang/dmd/pull/12507

https://news.ycombinator.com/item?id=27102584

A new generated code alone is 4000 lines long [1]. The actual code added is just 2000 lines, and some are used to pay debts, I mean, to make a proper code generator (which can be alternatively written in a simpler scripting langauge). In any case it is never comparable to the entier C parser proper.

[1] https://github.com/dlang/dmd/pull/15307/files#diff-3677bcc89...

D is completely opensource already (https://github.com/dlang/dmd). The "open" of OpenD is just ADR saying that OpenD will be more open to new language features than D has historically been.

The reference compiler, DMD, is open source: https://github.com/dlang/dmd

But they don't accept just any Pull Request or features the community submits, understandably. There's a process called DIP for language improvements: https://github.com/dlang/DIPs/blob/master/DIPs/README.md

However, by some accounts, it's really hard to get anything through.

Given D already has so many feature, I find that to be a good thing , to be honest, by not everyone agrees, of course.