karpal-profunctor 0.6.1

Profunctor hierarchy (Profunctor, Strong, Choice) for the Industrial Algebra ecosystem
Documentation 
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// Copyright (C) 2026 Industrial Algebra
// SPDX-License-Identifier: Apache-2.0

use crate::profunctor::Profunctor;

/// A `Choice` profunctor can lift a `P<A, B>` into `P<Result<A, C>, Result<B, C>>`.
///
/// This is the key ingredient for profunctor-encoded prisms.
/// Uses `Result<L, R>` as the sum type (idiomatic Rust, no custom `Either`).
pub trait Choice: Profunctor {
    fn left<A, B, C>(pab: Self::P<A, B>) -> Self::P<Result<A, C>, Result<B, C>>
    where
        A: 'static,
        B: 'static,
        C: 'static;

    fn right<A, B, C>(pab: Self::P<A, B>) -> Self::P<Result<C, A>, Result<C, B>>
    where
        A: 'static,
        B: 'static,
        C: 'static;
}