215 lines
5.6 KiB
JavaScript
215 lines
5.6 KiB
JavaScript
import { pipe } from './function';
|
|
// -------------------------------------------------------------------------------------
|
|
// constructors
|
|
// -------------------------------------------------------------------------------------
|
|
/**
|
|
* @category constructors
|
|
* @since 2.0.0
|
|
*/
|
|
export var fromEquals = function (equals) { return ({
|
|
equals: function (x, y) { return x === y || equals(x, y); }
|
|
}); };
|
|
// -------------------------------------------------------------------------------------
|
|
// combinators
|
|
// -------------------------------------------------------------------------------------
|
|
/**
|
|
* @since 2.10.0
|
|
*/
|
|
export var struct = function (eqs) {
|
|
return fromEquals(function (first, second) {
|
|
for (var key in eqs) {
|
|
if (!eqs[key].equals(first[key], second[key])) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
});
|
|
};
|
|
/**
|
|
* Given a tuple of `Eq`s returns a `Eq` for the tuple
|
|
*
|
|
* @example
|
|
* import { tuple } from 'fp-ts/Eq'
|
|
* import * as S from 'fp-ts/string'
|
|
* import * as N from 'fp-ts/number'
|
|
* import * as B from 'fp-ts/boolean'
|
|
*
|
|
* const E = tuple(S.Eq, N.Eq, B.Eq)
|
|
* assert.strictEqual(E.equals(['a', 1, true], ['a', 1, true]), true)
|
|
* assert.strictEqual(E.equals(['a', 1, true], ['b', 1, true]), false)
|
|
* assert.strictEqual(E.equals(['a', 1, true], ['a', 2, true]), false)
|
|
* assert.strictEqual(E.equals(['a', 1, true], ['a', 1, false]), false)
|
|
*
|
|
* @since 2.10.0
|
|
*/
|
|
export var tuple = function () {
|
|
var eqs = [];
|
|
for (var _i = 0; _i < arguments.length; _i++) {
|
|
eqs[_i] = arguments[_i];
|
|
}
|
|
return fromEquals(function (first, second) { return eqs.every(function (E, i) { return E.equals(first[i], second[i]); }); });
|
|
};
|
|
/* istanbul ignore next */
|
|
var contramap_ = function (fa, f) { return pipe(fa, contramap(f)); };
|
|
/**
|
|
* A typical use case for `contramap` would be like, given some `User` type, to construct an `Eq<User>`.
|
|
*
|
|
* We can do so with a function from `User -> X` where `X` is some value that we know how to compare
|
|
* for equality (meaning we have an `Eq<X>`)
|
|
*
|
|
* For example, given the following `User` type, we want to construct an `Eq<User>` that just looks at the `key` field
|
|
* for each user (since it's known to be unique).
|
|
*
|
|
* If we have a way of comparing `UUID`s for equality (`eqUUID: Eq<UUID>`) and we know how to go from `User -> UUID`,
|
|
* using `contramap` we can do this
|
|
*
|
|
* @example
|
|
* import { contramap, Eq } from 'fp-ts/Eq'
|
|
* import { pipe } from 'fp-ts/function'
|
|
* import * as S from 'fp-ts/string'
|
|
*
|
|
* type UUID = string
|
|
*
|
|
* interface User {
|
|
* readonly key: UUID
|
|
* readonly firstName: string
|
|
* readonly lastName: string
|
|
* }
|
|
*
|
|
* const eqUUID: Eq<UUID> = S.Eq
|
|
*
|
|
* const eqUserByKey: Eq<User> = pipe(
|
|
* eqUUID,
|
|
* contramap((user) => user.key)
|
|
* )
|
|
*
|
|
* assert.deepStrictEqual(
|
|
* eqUserByKey.equals(
|
|
* { key: 'k1', firstName: 'a1', lastName: 'b1' },
|
|
* { key: 'k2', firstName: 'a1', lastName: 'b1' }
|
|
* ),
|
|
* false
|
|
* )
|
|
* assert.deepStrictEqual(
|
|
* eqUserByKey.equals(
|
|
* { key: 'k1', firstName: 'a1', lastName: 'b1' },
|
|
* { key: 'k1', firstName: 'a2', lastName: 'b1' }
|
|
* ),
|
|
* true
|
|
* )
|
|
*
|
|
* @since 2.0.0
|
|
*/
|
|
export var contramap = function (f) { return function (fa) {
|
|
return fromEquals(function (x, y) { return fa.equals(f(x), f(y)); });
|
|
}; };
|
|
/**
|
|
* @category type lambdas
|
|
* @since 2.0.0
|
|
*/
|
|
export var URI = 'Eq';
|
|
/**
|
|
* @category instances
|
|
* @since 2.5.0
|
|
*/
|
|
export var eqStrict = {
|
|
equals: function (a, b) { return a === b; }
|
|
};
|
|
var empty = {
|
|
equals: function () { return true; }
|
|
};
|
|
/**
|
|
* @category instances
|
|
* @since 2.10.0
|
|
*/
|
|
export var getSemigroup = function () { return ({
|
|
concat: function (x, y) { return fromEquals(function (a, b) { return x.equals(a, b) && y.equals(a, b); }); }
|
|
}); };
|
|
/**
|
|
* @category instances
|
|
* @since 2.6.0
|
|
*/
|
|
export var getMonoid = function () { return ({
|
|
concat: getSemigroup().concat,
|
|
empty: empty
|
|
}); };
|
|
/**
|
|
* @category instances
|
|
* @since 2.7.0
|
|
*/
|
|
export var Contravariant = {
|
|
URI: URI,
|
|
contramap: contramap_
|
|
};
|
|
// -------------------------------------------------------------------------------------
|
|
// deprecated
|
|
// -------------------------------------------------------------------------------------
|
|
/**
|
|
* Use [`tuple`](#tuple) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var getTupleEq = tuple;
|
|
/**
|
|
* Use [`struct`](#struct) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var getStructEq = struct;
|
|
/**
|
|
* Use [`eqStrict`](#eqstrict) instead
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var strictEqual = eqStrict.equals;
|
|
/**
|
|
* This instance is deprecated, use small, specific instances instead.
|
|
* For example if a function needs a `Contravariant` instance, pass `E.Contravariant` instead of `E.eq`
|
|
* (where `E` is from `import E from 'fp-ts/Eq'`)
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var eq = Contravariant;
|
|
/**
|
|
* Use [`Eq`](./boolean.ts.html#eq) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var eqBoolean = eqStrict;
|
|
/**
|
|
* Use [`Eq`](./string.ts.html#eq) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var eqString = eqStrict;
|
|
/**
|
|
* Use [`Eq`](./number.ts.html#eq) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var eqNumber = eqStrict;
|
|
/**
|
|
* Use [`Eq`](./Date.ts.html#eq) instead.
|
|
*
|
|
* @category zone of death
|
|
* @since 2.0.0
|
|
* @deprecated
|
|
*/
|
|
export var eqDate = {
|
|
equals: function (first, second) { return first.valueOf() === second.valueOf(); }
|
|
};
|