https://github.com/purpleclay/chomp
A parser combinator library for Go that makes parsing text intuitive and maintainable
https://github.com/purpleclay/chomp
chomp go parser parser-combinators runes strings
Last synced: 5 months ago
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A parser combinator library for Go that makes parsing text intuitive and maintainable
- Host: GitHub
- URL: https://github.com/purpleclay/chomp
- Owner: purpleclay
- License: mit
- Created: 2023-12-29T16:11:19.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2026-01-31T07:24:22.000Z (5 months ago)
- Last Synced: 2026-01-31T20:52:51.415Z (5 months ago)
- Topics: chomp, go, parser, parser-combinators, runes, strings
- Language: Go
- Homepage:
- Size: 166 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Codeowners: .github/CODEOWNERS
Awesome Lists containing this project
README
# Chomp
[](LICENSE)
A parser combinator library for Go that makes parsing text intuitive and maintainable. Stop wrestling with regex and start writing parsers that read like natural grammar.
> Inspired by [nom](https://github.com/rust-bakery/nom) 💜.
## Why Chomp?
Parser combinators offer significant advantages over regular expressions:
| | Chomp | Regex |
|---|-------|-------|
| **Readability** | Reads like grammar rules | Often "write-only" patterns |
| **Composability** | Build complex parsers from simple, reusable pieces | Monolithic patterns that resist reuse |
| **Error Messages** | Clear context on what failed and where | Generic "no match" or cryptic positions |
| **Maintainability** | Easy to modify and extend | Small changes can break everything |
| **Nested Structures** | Natural support for recursion | Struggles or impossible |
| **Type Safety** | Compile-time guarantees | Runtime string manipulation |
## Installation
```sh
go get github.com/purpleclay/chomp
```
## How It Works
At the heart of `chomp` is the **combinator** - a function that attempts to parse text and returns a tuple `(rem, ext, err)`:
```
input
│
▼
┌─────────────────────┐
│ Combinator │
└─────────────────────┘
│
┌──────────────┼──────────────┐
▼ ▼ ▼
┌───────────┐ ┌───────────┐ ┌───────────┐
│ rem │ │ ext │ │ err │
└───────────┘ └───────────┘ └───────────┘
remaining extracted error (if any)
text text
```
```go
// Parse a simple tag
rem, ext, _ := chomp.Tag("Hello")("Hello, World!")
// ext: "Hello"
// rem: ", World!"
```
Combinators can be composed together to build sophisticated parsers:
```go
// Parse a key-value pair like "name=alice"
func KeyValue() chomp.Combinator[[]string] {
return chomp.SepPair(
chomp.While(chomp.IsLetter), // key: letters
chomp.Tag("="), // separator (discarded)
chomp.While(chomp.IsLetter), // value: letters
)
}
rem, kv, _ := KeyValue()("name=alice&age=30")
// kv: ["name", "alice"]
// rem: "&age=30"
```
## Examples
Real-world parser examples:
- [GPG Private Key Parser](examples/gpg/main.go) - Parse GPG key metadata
- [Git Diff Parser](examples/git-diff/main.go) - Parse unified diff output
## Documentation
- [Combinator Reference](docs/combinators.md) - All available combinators
- [Benchmarks](docs/benchmarks.md) - Performance benchmarks