Roger-luo/Moshi.jl

nextgen MLStyle: Generic Algebraic Data Type + Pattern Match

Moshi

Moshi is the pattern in Chinese （模式）. This package is the refactor of MLStyle with

• more correct pattern language for pattern match with @match
• type-stable algebra data type/tagged union with generics via @data
• traits, derive macro @derive from rust

Important

This project is in the early stage of development. The macro syntax has been iterated acorss several packages including Expronicon, MLStyle. The syntax are mostly stable. However, the API and features are subject to change.

Installation

Moshi is a   Julia Language   package. To install Moshi, please open Julia's interactive session (known as REPL) and press ] key in the REPL to use the package mode, then type the following command

pkg> add Moshi

Quick Example

Here is a quick example of defining a simple algebraic data type:

using Moshi.Data: @data

@data Message begin
    Quit
    struct Move
        x::Int
        y::Int
    end

    Write(String)
    ChangeColor(Int, Int, Int)
end

For pattern matching, if you already used MLStyle, the syntax is very similar:

using Moshi.Match: @match

@match [1.0, 2, 3] begin
    [1, xs::Float64...] => xs
end

@match (1, 2.0, "a") begin
    (1, x::Int, y::String) => x
    (1, x::Real, y::String) => y
end

Benchmark

License

MIT License