Crate frunk_core

Frunk Core

This library forms the core of Frunk. It should ideally be minimalistic, containing only the fundamental building blocks of generic programming.

Examples

let h = hlist![1, false, 42f32];
let folded = h.foldr(hlist![|i, acc| i + acc,
    |_, acc| if acc > 42f32 { 9000 } else { 0 },
    |f, acc| f + acc],
    1f32);
assert_eq!(folded, 9001);

// Reverse
let h1 = hlist![true, "hi"];
assert_eq!(h1.into_reverse(), hlist!["hi", true]);

// foldr (foldl also available)
let h2 = hlist![1, false, 42f32];
let folded = h2.foldr(
            hlist![|i, acc| i + acc,
                   |_, acc| if acc > 42f32 { 9000 } else { 0 },
                   |f, acc| f + acc],
            1f32
    );
assert_eq!(folded, 9001);

// Mapping over an HList
let h3 = hlist![9000, "joe", 41f32];
let mapped = (&h3).map(hlist![|&n| n + 1,
                              |&s| s,
                              |&f| f + 1f32]);
assert_eq!(mapped, hlist![9001, "joe", 42f32]);

// Plucking a value out by type
let h4 = hlist![1, "hello", true, 42f32];
let (t, remainder): (bool, _) = h4.pluck();
assert!(t);
assert_eq!(remainder, hlist![1, "hello", 42f32]);

// Resculpting an HList
let h5 = hlist![9000, "joe", 41f32, true];
let (reshaped, remainder2): (Hlist![f32, i32, &str], _) = h5.sculpt();
assert_eq!(reshaped, hlist![41f32, 9000, "joe"]);
assert_eq!(remainder2, hlist![true]);

Links: 1. Source on Github 2. Crates.io page

Modules

generic	This module holds the machinery behind Generic.
hlist	Module that holds HList data structures, implementations, and typeclasses.
labelled	This module holds the machinery behind LabelledGeneric.

Macros

Hlist	Returns a type signature for an HList of the provided types
field	Used for creating a Field
hlist	Returns an HList based on the values passed in.
hlist_pat	Macro for pattern-matching on HLists.