fp_library/classes/
pointed.rs

1//! Contexts that can be initialized with a value via the [`pure`] operation.
2//!
3//! ### Examples
4//!
5//! ```
6//! use fp_library::{functions::*, brands::*};
7//!
8//! let x = pure::<OptionBrand, _>(5);
9//! assert_eq!(x, Some(5));
10//! ```
11
12use crate::{Apply, kinds::*};
13use fp_macros::doc_params;
14use fp_macros::doc_type_params;
15use fp_macros::hm_signature;
16
17/// A type class for contexts that can be initialized with a value.
18pub trait Pointed: Kind_cdc7cd43dac7585f {
19	/// The value wrapped in the context.
20	///
21	/// This method wraps a value in a context.
22	///
23	/// ### Type Signature
24	///
25	#[hm_signature(Pointed)]
26	///
27	/// ### Type Parameters
28	///
29	#[doc_type_params("The lifetime of the value.", "The type of the value to wrap.")]
30	///
31	/// ### Parameters
32	///
33	#[doc_params("The value to wrap.")]
34	///
35	/// ### Returns
36	///
37	/// A new context containing the value.
38	///
39	/// ### Examples
40	///
41	/// ```
42	/// use fp_library::{functions::*, brands::*};
43	///
44	/// let x = pure::<OptionBrand, _>(5);
45	/// assert_eq!(x, Some(5));
46	/// ```
47	fn pure<'a, A: 'a>(a: A) -> Apply!(<Self as Kind!( type Of<'a, T: 'a>: 'a; )>::Of<'a, A>);
48}
49
50/// The value wrapped in the context.
51///
52/// Free function version that dispatches to [the type class' associated function][`Pointed::pure`].
53///
54/// ### Type Signature
55///
56#[hm_signature(Pointed)]
57///
58/// ### Type Parameters
59///
60#[doc_type_params(
61	"The lifetime of the value.",
62	"The brand of the context.",
63	"The type of the value to wrap."
64)]
65///
66/// ### Parameters
67///
68#[doc_params("The value to wrap.")]
69///
70/// ### Returns
71///
72/// A new context containing the value.
73///
74/// ### Examples
75///
76/// ```
77/// use fp_library::{functions::*, brands::*};
78///
79/// let x = pure::<OptionBrand, _>(5);
80/// assert_eq!(x, Some(5));
81/// ```
82pub fn pure<'a, Brand: Pointed, A: 'a>(
83	a: A
84) -> Apply!(<Brand as Kind!( type Of<'a, T: 'a>: 'a; )>::Of<'a, A>) {
85	Brand::pure(a)
86}
fp_library/classes/pointed.rs

fp_library/classes/
pointed.rs
