Formattable.flix

/*
 * Copyright 2025 Magnus Madsen
 *
 * Use of this source code is governed by the Apache 2.0 license
 * that can be found in the LICENSE.md file.
 */

pub mod Formattable {

    ///
    /// A trait for types that can be formatted as a `RichString`.
    ///
    pub trait Formattable[a] {
        ///
        /// The associated effect of the Formattable which represents the effect of formatting.
        ///
        type Aef[a]: Eff = {}

        pub def format(x: a): RichString \ Formattable.Aef[a]
    }

    instance Formattable[Unit] {
        pub def format(x: Unit): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Bool] {
        pub def format(x: Bool): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Char] {
        pub def format(x: Char): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Int8] {
        pub def format(x: Int8): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Int16] {
        pub def format(x: Int16): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Int32] {
        pub def format(x: Int32): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Int64] {
        pub def format(x: Int64): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Float32] {
        pub def format(x: Float32): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[Float64] {
        pub def format(x: Float64): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[String] {
        pub def format(x: String): RichString = RichString.fromString(x)
    }

    instance Formattable[BigInt] {
        pub def format(x: BigInt): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[BigDecimal] {
        pub def format(x: BigDecimal): RichString = RichString.fromString(ToString.toString(x))
    }

    instance Formattable[(a1, a2)] with Formattable[a1], Formattable[a2] {
        type Aef[(a1, a2)] = Formattable.Aef[a1] + Formattable.Aef[a2]

        pub def format(x: (a1, a2)): RichString \ Formattable.Aef[a1] + Formattable.Aef[a2] =
            let (v1, v2) = x;
            RichString.fromString("(") + Formattable.format(v1) + RichString.fromString(", ") + Formattable.format(v2) + RichString.fromString(")")
    }

}