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![|acc, i| i + acc,
    |acc, _| if acc > 42f32 { 9000 } else { 0 },
    |acc, f| 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![|acc, i| i + acc,
                   |acc, _| if acc > 42f32 { 9000 } else { 0 },
                   |acc, f| f + acc],
            1f32
    );
assert_eq!(folded, 9001);

// Mapping over an HList
let h3 = hlist![9000, "joe", 41f32];
let mapped = h3.to_ref().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

• coproduct
  Module that holds Coproduct data structures, traits, and implementations
• generic
  This module holds the machinery behind Generic.
• hlist
  Module that holds HList data structures, implementations, and typeclasses.
• indices
  Types used for indexing into HLists and coproducts.
• labelled
  This module holds the machinery behind LabelledGeneric.
• path
  Holds models, traits, and logic for generic traversal of models
• traits
  Traits that provide generic functionality for multiple types in frunk

Macros

• Coprod
  Returns a type signature for a Coproduct of the provided types
• 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.
• poly_fn
  Returns a polymorphic function for use with mapping/folding heterogeneous types.