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Lissityyppei
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import * as L from "partial.lenses"; | |
interface State { | |
foo: { | |
lol: number; | |
bal: string; | |
}; | |
items: Item[]; | |
} | |
interface Item { | |
num: number; | |
} | |
// typeof state1 extends State | |
const state1 = { | |
foo: { | |
lol: 123, | |
bal: "asd" | |
}, | |
items: [{ num: 1, extra: "asdf" }, { num: 2 }], | |
extra: "asd" | |
}; | |
// typeof state1 extends State | |
const state2 = { | |
foo: { | |
lol: 123, | |
bal: "asd", | |
extra: "adasd" | |
}, | |
items: [] | |
}; | |
// perus linssi | |
const stateBal = L.compose( | |
L.identity<State>(), | |
L.prop("foo"), | |
L.prop("bal") | |
); | |
// traversal | |
const stateItemNums = L.compose( | |
L.identity<State>(), | |
L.prop("items"), | |
L.elems(), | |
L.prop("num") | |
); | |
const t11 = L.set(stateBal, "tsers", state1); | |
const t12 = L.set(stateBal, "tsers", state2) | |
t11.extra; // toimii | |
t12.foo.extra; // toimii | |
const t21 = L.set(stateItemNums, 2, state1); | |
t21.items[0].extra; // toimii |
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declare module "partial.lenses" { | |
// Tyypit | |
export interface Lens<S, T> { | |
__s: S; | |
__t: T; | |
} | |
export interface Traversal<E> extends Lens<E[], E> { | |
__t: E; | |
} | |
// Operaattorit | |
export function get<S, T, D extends S>(lens: Lens<S, T>, data: D): T; | |
export function set<S, T, V extends T, D extends S>( | |
lens: Lens<S, T>, | |
value: V, | |
data: D | |
): D; | |
export function modify<S, T, V extends T, D extends S>( | |
lens: Lens<S, T>, | |
f: (value: V) => V, | |
data: D | |
): D; | |
// Kompositio | |
export function compose<A, B, C>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C> | |
): Lens<A, C>; | |
export function compose<A, B, C, D>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D> | |
): Lens<A, D>; | |
export function compose<A, B, C, D, E>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D>, | |
d2e: Lens<D, E> | |
): Lens<A, E>; | |
export function compose<A, B, C, D, E, F>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D>, | |
d2e: Lens<D, E>, | |
e2f: Lens<E, F> | |
): Lens<A, F>; | |
export function compose<A, B, C, D, E, F, G>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D>, | |
d2e: Lens<D, E>, | |
e2f: Lens<E, F>, | |
f2g: Lens<F, G> | |
): Lens<A, G>; | |
export function compose<A, B, C, D, E, F, G, H>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D>, | |
d2e: Lens<D, E>, | |
e2f: Lens<E, F>, | |
f2g: Lens<F, G>, | |
g2h: Lens<G, H> | |
): Lens<A, H>; | |
export function compose<A, B, C, D, E, F, G, H, I>( | |
a2b: Lens<A, B>, | |
b2c: Lens<B, C>, | |
c2d: Lens<C, D>, | |
d2e: Lens<D, E>, | |
e2f: Lens<E, F>, | |
f2g: Lens<F, G>, | |
g2h: Lens<G, H>, | |
h2i: Lens<H, I> | |
): Lens<A, I>; // ... ja näitä vaan lissee... | |
// Linssien konstruktorit | |
export function prop<S extends object, K extends keyof S>( | |
name: K | |
): Lens<S, S[K]>; | |
// HUOM HUOM !!! Nää ei ole siis funktioita oikeesti vaan vakiolinssejä. | |
// Tyypittien inferoinnin takia niille pitäs tehdä tämmöset vastaavat | |
// funktiot, jotta esim. kompositio onnistuu kääntäjän toimesta... | |
export function identity<S>(): Lens<S, S>; | |
export function elems<E>(): Traversal<E>; | |
} |
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