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svelte
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pull/4668/head
pushkine 6 years ago
parent 3aefd1a38a
commit 9efe5c0364
2 changed files with 96 additions and 77 deletions
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21
src/runtime/internal/utils.ts
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@ -1,3 +1,5 @@
import { Store, Unsubscriber } from '../store';
export function noop() {}
export const identity = x => x;
@ -14,7 +16,7 @@ export function is_promise<T = any>(value: any): value is PromiseLike<T> {
export function add_location(element, file, line, column, char) {
element.__svelte_meta = {
loc: { file, line, column, char }
loc: { file, line, column, char },
};
}
@ -35,7 +37,7 @@ export function is_function(thing: any): thing is Function {
}
export function safe_not_equal(a, b) {
return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function');
return a != a ? b == b : a !== b || (a && typeof a === 'object') || typeof a === 'function';
}
export function not_equal(a, b) {
@ -48,17 +50,16 @@ export function validate_store(store, name) {
}
}
export function subscribe(store, ...callbacks) {
if (store == null) {
return noop;
}
export function subscribe<T>(store: Store<T>, ...callbacks: Parameters<Store<T>['subscribe']>): Unsubscriber {
if (store == null) return noop;
const unsub = store.subscribe(...callbacks);
// @ts-ignore
return unsub.unsubscribe ? () => unsub.unsubscribe() : unsub;
}
export function get_store_value(store) {
let value;
subscribe(store, _ => value = _)();
subscribe(store, _ => (value = _))();
return value;
}
@ -74,9 +75,7 @@ export function create_slot(definition, ctx, $$scope, fn) {
}
export function get_slot_context(definition, ctx, $$scope, fn) {
return definition[1] && fn
? assign($$scope.ctx.slice(), definition[1](fn(ctx)))
: $$scope.ctx;
return definition[1] && fn ? assign($$scope.ctx.slice(), definition[1](fn(ctx))) : $$scope.ctx;
}
export function get_slot_changes(definition, $$scope, dirty, fn) {
@ -118,7 +117,7 @@ export function compute_rest_props(props, keys) {
export function once(fn) {
let ran = false;
return function(this: any, ...args) {
return function (this: any, ...args) {
if (ran) return;
ran = true;
fn.call(this, ...args);

150
src/runtime/store/index.ts
Unescape View File

@ -1,4 +1,10 @@
import { subscribe, noop, safe_not_equal, get_store_value } from 'svelte/internal';
import { subscribe, noop, safe_not_equal, get_store_value } from '../internal/utils';
/**
* Get the current value from a store by subscribing and immediately unsubscribing.
* @param store readable
*/
export { get_store_value as get };
/** Sets the value of a store. */
type Setter<T> = (value: T) => void;
@ -9,15 +15,17 @@ type StopCallback = () => void;
* If a callback is returned it will be called on last removed subscriber */
type StartStopNotifier<T> = (set: Setter<T>) => StopCallback | void;
type Subscriber<T> = (value: T) => void;
type Unsubscriber = () => void;
export type Unsubscriber = () => void;
type Updater<T> = (value: T) => T;
/** Internal callback, invalidates every store before updating */
/** Internal callback, used to invalidate every store before updating */
type Invalidator = () => void;
type SubscribeInvalidateTuple<T> = [Subscriber<T>, Invalidator];
type Store<T> = Writable<T> | Readable<T>;
export type Store<T> = Writable<T> | Readable<T>;
type ArrayStore = Array<Store<any>>;
type SingleStore = Store<any>;
type ValuesOf<T> = { [K in keyof T]: T[K] extends Store<infer U> ? U : never };
type ValueOf<T> = T extends Store<infer U> ? U : never;
type StoreValues<T> = T extends Store<any> ? ValueOf<T> : ValuesOf<T>;
type StoreValues<T> = T extends Store<any> ? ValueOf<T> : T extends ArrayStore ? ValuesOf<T> : T;
/** The value of the derived store is the value returned by the function */
type AutoDeriver<S, T> = (values: StoreValues<S>) => T;
/** The value of the derived store is set manually through Setter calls */
@ -106,6 +114,7 @@ export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writa
return { set, update, subscribe };
}
/**
* Derived value store by synchronizing one or more readable stores and
* applying an aggregation function over its input values.
@ -114,75 +123,86 @@ export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writa
* @param fn - function callback that aggregates the values
* @param initial_value - when used asynchronously
*/
export function derived<S extends Store<any> | Array<Store<any>>, F extends Deriver<S, T | any>, T = DerivedValue<F>>(
export function derived<S extends SingleStore | ArrayStore, F extends Deriver<S, T | any>, T = DerivedValue<F>>(
stores: S,
fn: F,
initial_value?: T
) {
const mode = fn.length < 2 ? auto(fn as AutoDeriver<S, T>) : manual(fn as ManualDeriver<S, T>);
const deriver = Array.isArray(stores)
? multiple(stores as Array<Store<any>>, mode)
: single(stores as Store<any>, mode);
const mode: DeriverController = fn.length < 2 ? auto(fn as AutoDeriver<S, T>) : manual(fn as ManualDeriver<S, T>);
const deriver = Array.isArray(stores) ? multiple(stores as ArrayStore, mode) : single(stores as SingleStore, mode);
return readable(initial_value, deriver) as Readable<T>;
}
function single<S, T>(store: S, controller: DeriverController): StartStopNotifier<T> {
return set => {
const unsub = subscribe(store, value => controller.update(value, set));
return function stop() {
unsub(), controller.cleanup();
};
/** DERIVING LOGIC */
/**
* derived from a single store
*
* derived store StartStopNotifier function when given a single store
* */
const single = <T>(store: SingleStore, controller: DeriverController): StartStopNotifier<T> => set => {
const unsub = subscribe(store, value => controller.update(value, set));
return function stop() {
unsub(), controller.cleanup();
};
}
function multiple<S extends Array<Store<any>>, T>(stores: S, controller: DeriverController): StartStopNotifier<T> {
return set => {
let inited = false;
let pending = 0;
const values = new Array(stores.length) as StoreValues<S>;
function sync() {
if (inited && !pending) {
controller.update(values, set);
};
/** derived store StartStopNotifier function when given an array of stores */
const multiple = <T>(stores: ArrayStore, controller: DeriverController): StartStopNotifier<T> => set => {
const values = new Array(stores.length);
let inited = false;
let pending = 0;
const sync = () => inited && !pending && controller.update(values, set);
const unsubs = stores.map((store, index) =>
subscribe(
store,
value => {
values[index] = value;
pending &= ~(1 << index);
sync();
},
() => {
pending |= 1 << index;
}
}
const unsubs = stores.map((store, index) =>
subscribe(
store,
value => {
values[index] = value;
pending &= ~(1 << index);
sync();
},
() => {
pending |= 1 << index;
}
)
);
(inited = true), sync();
return function stop() {
unsubs.forEach(v => v()), controller.cleanup();
};
};
}
function auto(fn): DeriverController {
return {
update(payload, set) {
set(fn(payload));
},
cleanup: noop,
};
}
function manual(fn): DeriverController {
return {
update(payload, set) {
this.cleanup();
this.cleanup = fn(payload, set) as Unsubscriber;
if (typeof this.cleanup !== 'function') this.cleanup = noop;
},
cleanup: noop,
)
);
(inited = true), sync();
return function stop() {
unsubs.forEach(v => v()), controller.cleanup();
};
}
};
/** UPDATE/CLEANUP CONTROLLERS */
/**
* Get the current value from a store by subscribing and immediately unsubscribing.
* @param store readable
* mode "auto" : function has <2 arguments
*
* derived value = value returned by the function
*
*/
export { get_store_value as get };
const auto = (fn: AutoDeriver<any, any>): DeriverController => ({
update(payload, set) {
set(fn(payload));
},
cleanup: noop,
});
/**
* mode "manual" : function has >1 arguments
*
* derived value = value set manually
* before each update => callback returned by the function
*
* note : [(...args) does not count as an argument]
*/
const manual = (fn: ManualDeriver<any, any>): DeriverController => ({
update(payload, set) {
this.cleanup();
this.cleanup = fn(payload, set) as Unsubscriber;
if (typeof this.cleanup !== 'function') this.cleanup = noop;
},
cleanup: noop,
});

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