An implementation of parser combinators for Rust, inspired by the Haskell library Parsec. As in Parsec the parsers are LL(1) by default but they can opt-in to arbitrary lookahead using the try combinator.
```rust extern crate combine; use combine::{many1, Parser, sep_by}; use combine::char::{letter, space};
// Construct a parser that parses many (and at least 1) *letters let word = many1(letter());
// Construct a parser that parses many words where each word is separated by a (white)space
let mut parser = sepby(word, space())
// Combine can collect into any type implementing Default + Extend so we need to assist rustc
// by telling it that sep_by should collect into a Vec and many1 should collect to a String
.map(|mut words: Vecparse returns Result where Ok contains a tuple of the parsers output and any remaining input.
assert
Larger examples can be found in the examples, tests and benches folders.
A parser combinator is, broadly speaking, a function which takes several parsers as arguments and returns a new parser, created by combining those parsers. For instance, the many parser takes one parser, p, as input and returns a new parser which applies p zero or more times. Thanks to the modularity that parser combinators gives it is possible to define parsers for a wide range of tasks without needing to implement the low level plumbing while still having the full power of Rust when you need it.
The library adheres to semantic versioning.
If you end up trying it I welcome any feedback from your experience with it. I am usually reachable within a day by opening an issue, sending an email or posting a message on gitter.
Since combine aims to crate parsers with little to no overhead streams over &str and &[T] do not carry any extra position information but instead only rely on comparing the pointer of the buffer to check which Stream is further ahead than another Stream. To retrieve a better position, either call translate_position on the PointerOffset which represents the position or wrap your stream with State.
https://github.com/Marwes/combine/issues/73 contains discussion and links to comparisons to nom.
There is an additional crate which has parsers to lex and parse programming languages in combine-language.
You can find older versions of combine (parser-combinators) here.
Current master is the 3.0.0 branch. If you want to submit a fix or feature to the 2.x version of combine then do so to the 2.x branch or submit the PR to master and request that it be backported.
The easiest way to contribute is to just open an issue about any problems you encounter using combine but if you are interested in adding something to the library here is a list of some of the easier things to work on to get started.