Pickle 🥒

A parser combinator library for Gleam that supports all targets.

Pickle’s API does heavily rely on pipelines, thus you can create powerful parsers by chaining multiple parsers together with the pipe operator.

Pickle also takes a different approach on its API design. In Pickle you provide an initial value to the parser (e.g., an empty string, list, or AST container) that’s being transformed during parsing. Parsers often come with mapper parameters, which let you control how to transform the current value with the parsed value of the respective parser.

Maintenance Notice 🥒

As of the 11th of August 2024, I won’t be maintaining this project any longer.

I don’t invest time in Gleam anymore, as I encountered too many breaking changes within minor version bumps.

I wish Gleam all the best, but I revert to other (enterprise-y) languages I’m already used to.

Demo 🥒

import gleam/io
import gleam/string
import pickle.{type Parser}

type Point {
  Point(x: Int, y: Int)
}

fn new_point() -> Point {
  Point(0, 0)
}

fn point_parser() -> Parser(Point, Point, String) {
  pickle.string("(", pickle.drop)
  |> pickle.then(pickle.integer(fn(point, x) { Point(..point, x: x) }))
  |> pickle.then(pickle.string(",", pickle.drop))
  |> pickle.then(pickle.integer(fn(point, y) { Point(..point, y: y) }))
  |> pickle.then(pickle.string(")", pickle.drop))
}

pub fn main() {
  let assert Ok(point) =
    pickle.parse("(100,-25)", new_point(), point_parser())

  string.inspect(point) |> io.print() // prints "Point(100, -25)"
}