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derive-state

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derive-state - npm Package Compare versions

Comparing version 0.1.0-alpha.3 to 0.1.0-alpha.4

313

dist/derive-state.cjs.development.js

@@ -21,8 +21,2 @@ 'use strict';

function _inheritsLoose(subClass, superClass) {
subClass.prototype = Object.create(superClass.prototype);
subClass.prototype.constructor = subClass;
subClass.__proto__ = superClass;
}
var ObserverList = /*#__PURE__*/function () {

@@ -67,2 +61,9 @@ function ObserverList() {

_createClass(ObserverList, [{
key: "size",
get: function get() {
return this.observers.size;
}
}]);
return ObserverList;

@@ -74,29 +75,23 @@ }();

var DerivedState = /*#__PURE__*/function () {
function DerivedState(derive) {
var _this = this;
var State = /*#__PURE__*/function () {
function State(initialValue) {
this.observerList = new ObserverList();
this.state = EMPTY;
this.teardown = derive({
next: function next(_next) {
if (_this.observerList.closed) {
throw new Error("Can't set the value of a closed ObservableState");
}
this.teardown = noop;
_this.state = _next;
if (arguments.length >= 1) {
this.state = initialValue;
}
}
_this.observerList.emit(_next);
},
complete: function complete() {
return _this.close();
}
}) || noop; // For synchronous completes
var _proto = State.prototype;
_proto.setValue = function setValue(newState) {
if (this.observerList.closed) {
this.teardown();
throw new Error("Can't set the value of a closed ObservableState");
}
}
var _proto = DerivedState.prototype;
this.state = newState;
this.observerList.emit(newState);
};

@@ -120,2 +115,35 @@ _proto.subscribe = function subscribe(next, complete) {

_proto.pipe = function pipe() {
for (var _len = arguments.length, operators = new Array(_len), _key = 0; _key < _len; _key++) {
operators[_key] = arguments[_key];
}
var firstOp = operators[0],
rest = operators.slice(1);
var first = firstOp(this);
var current = first;
rest.forEach(function (operator) {
current = operator(current);
});
return Object.assign(current, {
kill: function kill() {
return first.close();
}
});
};
_proto.appendTeardown = function appendTeardown(teardown) {
var old = this.teardown;
this.teardown = function () {
old();
teardown();
};
};
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
_proto.hasValue = function hasValue() {

@@ -133,19 +161,11 @@ return this.state !== EMPTY;

_proto.close = function close() {
var _this$teardown;
// On synchronous completes, this.teardown can possibly not be defined yet
(_this$teardown = this.teardown) == null ? void 0 : _this$teardown.call(this);
this.observerList.close();
};
_createClass(DerivedState, [{
_createClass(State, [{
key: "value",
get: function get() {
var _this2 = this;
var _this = this;
return new Promise(function (resolve, reject) {
if (_this2.hasValue()) return resolve(_this2.getValue());
if (_this.hasValue()) return resolve(_this.getValue());
var unsub = _this2.subscribe(function (v) {
var unsub = _this.subscribe(function (v) {
unsub();

@@ -160,39 +180,103 @@ resolve(v);

return DerivedState;
return State;
}();
var State = /*#__PURE__*/function (_DerivedState) {
_inheritsLoose(State, _DerivedState);
var EMPTY = /*#__PURE__*/Symbol('empty');
function State(initialValue) {
var _this3;
var Stateless = /*#__PURE__*/function () {
function Stateless(derive) {
if (derive === void 0) {
derive = noop;
}
var args = arguments;
var capturedObserver;
_this3 = _DerivedState.call(this, function (obs) {
capturedObserver = obs;
this.observerList = new ObserverList();
this.teardown = noop;
this.start = derive;
}
if (args.length >= 1) {
obs.next(initialValue);
}
}) || this;
var _proto = Stateless.prototype;
_this3.next = function (v) {
return capturedObserver.next(v);
_proto.emit = function emit(next) {
this.observerList.emit(next);
};
_proto.subscribe = function subscribe(next, complete) {
var _this = this;
var observer = {
next: next,
complete: complete || noop
};
return _this3;
}
if (this.observerList.closed) {
observer.complete();
return noop;
}
var _proto2 = State.prototype;
var unsub = this.observerList.addObserver(observer);
_proto2.setValue = function setValue(newState) {
this.next(newState);
if (this.observerList.size === 1) {
this.teardown = this.start({
next: function next(v) {
return _this.emit(v);
},
complete: function complete() {
return _this.close();
}
}) || noop;
}
return function () {
unsub();
if (_this.observerList.size === 0) {
_this.teardown();
}
};
};
return State;
}(DerivedState);
var EMPTY = /*#__PURE__*/Symbol('empty');
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
_proto.pipe = function pipe() {
for (var _len = arguments.length, operators = new Array(_len), _key = 0; _key < _len; _key++) {
operators[_key] = arguments[_key];
}
var firstOp = operators[0],
rest = operators.slice(1);
var first = firstOp(this);
var current = first;
rest.forEach(function (operator) {
current = operator(current);
});
return Object.assign(current, {
kill: function kill() {
return first.close();
}
});
};
_proto.capture = function capture() {
var state = new State();
var unsub = this.subscribe(function (n) {
return state.setValue(n);
}, function () {
return state.close();
});
state.appendTeardown(unsub);
return state;
};
return Stateless;
}();
var asStateless = function asStateless(observable) {
return new Stateless(function (obs) {
return observable.subscribe(obs.next, obs.complete);
});
};
var combine = function combine(input) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var active = false;

@@ -234,3 +318,3 @@ var value = Array.isArray(input) ? [] : {};

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var lastValue = EMPTY$1;

@@ -251,3 +335,3 @@ return source.subscribe(function (value) {

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
return source.subscribe(function (value) {

@@ -262,3 +346,3 @@ return filterFn(value) ? obs.next(value) : void 0;

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
return source.subscribe(function (value) {

@@ -272,3 +356,3 @@ return obs.next(mapFn(value));

var merge = function merge(observables) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var activeSubs = observables.length;

@@ -297,18 +381,5 @@

function pipe(source) {
var current = source;
for (var _len = arguments.length, operators = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
operators[_key - 1] = arguments[_key];
}
operators.forEach(function (operator) {
current = operator(current);
});
return current;
}
var skip = function skip(n) {
return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var i = 0;

@@ -328,3 +399,3 @@ return source.subscribe(function (v) {

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var state = {

@@ -344,3 +415,3 @@ skip: true

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var innerUnsub = function innerUnsub() {

@@ -363,3 +434,4 @@ return void 0;

activeSubs++;
innerUnsub = mapFn(value).subscribe(function (v) {
var inner$ = mapFn(value);
innerUnsub = inner$.subscribe(function (v) {
return obs.next(v);

@@ -378,3 +450,3 @@ }, handleComplete);

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
if (n < 1) {

@@ -410,3 +482,3 @@ return obs.complete();

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
obs.next(value);

@@ -418,74 +490,2 @@ return source.subscribe(obs.next, obs.complete);

var DerivedStateless = /*#__PURE__*/function () {
function DerivedStateless(derive) {
var _this = this;
this.observerList = new ObserverList();
this.teardown = derive({
next: function next(_next) {
return _this.observerList.emit(_next);
},
complete: function complete() {
return _this.close();
}
}) || noop;
}
var _proto = DerivedStateless.prototype;
_proto.subscribe = function subscribe(next, complete) {
var observer = {
next: next,
complete: complete || noop
};
if (this.observerList.closed) {
observer.complete();
return noop;
}
return this.observerList.addObserver(observer);
};
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
return DerivedStateless;
}();
var Stateless = /*#__PURE__*/function (_DerivedStateless) {
_inheritsLoose(Stateless, _DerivedStateless);
function Stateless() {
var _this2;
var capturedObserver;
_this2 = _DerivedStateless.call(this, function (obs) {
capturedObserver = obs;
}) || this;
_this2.next = function (v) {
return capturedObserver.next(v);
};
return _this2;
}
var _proto2 = Stateless.prototype;
_proto2.emit = function emit(newState) {
this.next(newState);
};
return Stateless;
}(DerivedStateless);
var asStateless = function asStateless(observable) {
return new DerivedStateless(function (obs) {
return observable.subscribe(obs.next, obs.complete);
});
};
exports.DerivedState = DerivedState;
exports.DerivedStateless = DerivedStateless;
exports.State = State;

@@ -499,3 +499,2 @@ exports.Stateless = Stateless;

exports.merge = merge;
exports.pipe = pipe;
exports.skip = skip;

@@ -502,0 +501,0 @@ exports.skipSynchronous = skipSynchronous;

2

dist/derive-state.cjs.production.min.js

@@ -1,2 +0,2 @@

"use strict";function t(t,e){t.prototype=Object.create(e.prototype),t.prototype.constructor=t,t.__proto__=e}Object.defineProperty(exports,"__esModule",{value:!0});var e=function(){function t(){this.observers=new Set,this.closed=!1}var e=t.prototype;return e.addObserver=function(t){var e=this;if(this.closed)throw new Error("StatelessObservable was closed, can't subscribe");return this.observers.add(t),function(){e.observers.delete(t)}},e.emit=function(t){if(this.closed)throw new Error("Observable was closed, can't emit new value");this.observers.forEach((function(e){return e.next(t)}))},e.close=function(){this.observers.forEach((function(t){return t.complete()})),this.observers.clear(),this.closed=!0},t}(),n=function(){},r=function(){function t(t){var r=this;this.observerList=new e,this.state=i,this.teardown=t({next:function(t){if(r.observerList.closed)throw new Error("Can't set the value of a closed ObservableState");r.state=t,r.observerList.emit(t)},complete:function(){return r.close()}})||n,this.observerList.closed&&this.teardown()}var r,o=t.prototype;return o.subscribe=function(t,e){var r={next:t,complete:e||n};if(this.observerList.closed)return this.state!==i&&t(this.state),null==e||e(),n;var o=this.observerList.addObserver(r);return this.state!==i&&t(this.state),o},o.hasValue=function(){return this.state!==i},o.getValue=function(){if(this.state===i)throw new Error("Can't retreive the value of the ObservableState, as it's empty");return this.state},o.close=function(){var t;null==(t=this.teardown)||t.call(this),this.observerList.close()},(r=[{key:"value",get:function(){var t=this;return new Promise((function(e,n){if(t.hasValue())return e(t.getValue());var r=t.subscribe((function(t){r(),e(t)}),(function(){return n(new Error("ObservableState completed without any value"))}))}))}}])&&function(t,e){for(var n=0;n<e.length;n++){var r=e[n];r.enumerable=r.enumerable||!1,r.configurable=!0,"value"in r&&(r.writable=!0),Object.defineProperty(t,r.key,r)}}(t.prototype,r),t}(),o=function(e){function n(t){var n,r,o=arguments;return(n=e.call(this,(function(e){r=e,o.length>=1&&e.next(t)}))||this).next=function(t){return r.next(t)},n}return t(n,e),n.prototype.setValue=function(t){this.next(t)},n}(r),i=Symbol("empty"),u=Symbol("empty"),s=function(){function t(t){var r=this;this.observerList=new e,this.teardown=t({next:function(t){return r.observerList.emit(t)},complete:function(){return r.close()}})||n}var r=t.prototype;return r.subscribe=function(t,e){var r={next:t,complete:e||n};return this.observerList.closed?(r.complete(),n):this.observerList.addObserver(r)},r.close=function(){this.teardown(),this.observerList.close()},t}(),c=function(e){function n(){var t,n;return(t=e.call(this,(function(t){n=t}))||this).next=function(t){return n.next(t)},t}return t(n,e),n.prototype.emit=function(t){this.next(t)},n}(s);exports.DerivedState=r,exports.DerivedStateless=s,exports.State=o,exports.Stateless=c,exports.asStateless=function(t){return new s((function(e){return t.subscribe(e.next,e.complete)}))},exports.combine=function(t){return new r((function(e){var n=!1,r=Array.isArray(t)?[]:{},o=Object.entries(t);if(0===o.length)return e.complete();var i=o.map((function(t){var i=t[0];return t[1].subscribe((function(t){r[i]=t,(n||Object.keys(r).length===o.length)&&(n=!0,e.next(r))}),e.complete)}));return function(){return i.forEach((function(t){return t()}))}}))},exports.distinctUntilChanged=function(t){return void 0===t&&(t=function(t,e){return t===e}),function(e){return new r((function(n){var r=u;return e.subscribe((function(e){r!==u&&t(e,r)||n.next(e),r=e}),n.complete)}))}},exports.filter=function(t){return function(e){return new r((function(n){return e.subscribe((function(e){return t(e)?n.next(e):void 0}),n.complete)}))}},exports.map=function(t){return function(e){return new r((function(n){return e.subscribe((function(e){return n.next(t(e))}),n.complete)}))}},exports.merge=function(t){return new r((function(e){var n=t.length;if(0===n)return e.complete();var r=t.map((function(t){return t.subscribe(e.next,(function(){0==--n&&e.complete()}))}));return function(){return r.forEach((function(t){return t()}))}}))},exports.pipe=function(t){for(var e=t,n=arguments.length,r=new Array(n>1?n-1:0),o=1;o<n;o++)r[o-1]=arguments[o];return r.forEach((function(t){e=t(e)})),e},exports.skip=function(t){return function(e){return new r((function(n){var r=0;return e.subscribe((function(e){r>=t?n.next(e):r++}),n.complete)}))}},exports.skipSynchronous=function(){return function(t){return new r((function(e){var n={skip:!0},r=t.subscribe((function(t){return n.skip?void 0:e.next(t)}),e.complete);return n.skip=!1,r}))}},exports.switchMap=function(t){return function(e){return new r((function(n){var r=function(){},o=1,i=function(){0==--o&&n.complete()},u=e.subscribe((function(e){r(),o++,r=t(e).subscribe((function(t){return n.next(t)}),i)}),i);return function(){r(),u()}}))}},exports.take=function(t){return function(e){return new r((function(n){if(t<1)return n.complete();var r=0,o=e.subscribe((function(e){r<t&&n.next(e),++r>=t&&(o&&o(),n.complete())}),n.complete);return r>=t&&(o(),n.complete()),o}))}},exports.withDefault=function(t){return function(e){return new r((function(n){return n.next(t),e.subscribe(n.next,n.complete)}))}};
"use strict";function e(e,t){for(var n=0;n<t.length;n++){var r=t[n];r.enumerable=r.enumerable||!1,r.configurable=!0,"value"in r&&(r.writable=!0),Object.defineProperty(e,r.key,r)}}function t(t,n,r){return n&&e(t.prototype,n),r&&e(t,r),t}Object.defineProperty(exports,"__esModule",{value:!0});var n=function(){function e(){this.observers=new Set,this.closed=!1}var n=e.prototype;return n.addObserver=function(e){var t=this;if(this.closed)throw new Error("StatelessObservable was closed, can't subscribe");return this.observers.add(e),function(){t.observers.delete(e)}},n.emit=function(e){if(this.closed)throw new Error("Observable was closed, can't emit new value");this.observers.forEach((function(t){return t.next(e)}))},n.close=function(){this.observers.forEach((function(e){return e.complete()})),this.observers.clear(),this.closed=!0},t(e,[{key:"size",get:function(){return this.observers.size}}]),e}(),r=function(){},i=function(){function e(e){this.observerList=new n,this.state=o,this.teardown=r,arguments.length>=1&&(this.state=e)}var i=e.prototype;return i.setValue=function(e){if(this.observerList.closed)throw new Error("Can't set the value of a closed ObservableState");this.state=e,this.observerList.emit(e)},i.subscribe=function(e,t){var n={next:e,complete:t||r};if(this.observerList.closed)return this.state!==o&&e(this.state),null==t||t(),r;var i=this.observerList.addObserver(n);return this.state!==o&&e(this.state),i},i.pipe=function(){for(var e=arguments.length,t=new Array(e),n=0;n<e;n++)t[n]=arguments[n];var r=t[0],i=t.slice(1),o=r(this),s=o;return i.forEach((function(e){s=e(s)})),Object.assign(s,{kill:function(){return o.close()}})},i.appendTeardown=function(e){var t=this.teardown;this.teardown=function(){t(),e()}},i.close=function(){this.teardown(),this.observerList.close()},i.hasValue=function(){return this.state!==o},i.getValue=function(){if(this.state===o)throw new Error("Can't retreive the value of the ObservableState, as it's empty");return this.state},t(e,[{key:"value",get:function(){var e=this;return new Promise((function(t,n){if(e.hasValue())return t(e.getValue());var r=e.subscribe((function(e){r(),t(e)}),(function(){return n(new Error("ObservableState completed without any value"))}))}))}}]),e}(),o=Symbol("empty"),s=function(){function e(e){void 0===e&&(e=r),this.observerList=new n,this.teardown=r,this.start=e}var t=e.prototype;return t.emit=function(e){this.observerList.emit(e)},t.subscribe=function(e,t){var n=this,i={next:e,complete:t||r};if(this.observerList.closed)return i.complete(),r;var o=this.observerList.addObserver(i);return 1===this.observerList.size&&(this.teardown=this.start({next:function(e){return n.emit(e)},complete:function(){return n.close()}})||r),function(){o(),0===n.observerList.size&&n.teardown()}},t.close=function(){this.teardown(),this.observerList.close()},t.pipe=function(){for(var e=arguments.length,t=new Array(e),n=0;n<e;n++)t[n]=arguments[n];var r=t[0],i=t.slice(1),o=r(this),s=o;return i.forEach((function(e){s=e(s)})),Object.assign(s,{kill:function(){return o.close()}})},t.capture=function(){var e=new i,t=this.subscribe((function(t){return e.setValue(t)}),(function(){return e.close()}));return e.appendTeardown(t),e},e}(),u=Symbol("empty");exports.State=i,exports.Stateless=s,exports.asStateless=function(e){return new s((function(t){return e.subscribe(t.next,t.complete)}))},exports.combine=function(e){return new s((function(t){var n=!1,r=Array.isArray(e)?[]:{},i=Object.entries(e);if(0===i.length)return t.complete();var o=i.map((function(e){var o=e[0];return e[1].subscribe((function(e){r[o]=e,(n||Object.keys(r).length===i.length)&&(n=!0,t.next(r))}),t.complete)}));return function(){return o.forEach((function(e){return e()}))}}))},exports.distinctUntilChanged=function(e){return void 0===e&&(e=function(e,t){return e===t}),function(t){return new s((function(n){var r=u;return t.subscribe((function(t){r!==u&&e(t,r)||n.next(t),r=t}),n.complete)}))}},exports.filter=function(e){return function(t){return new s((function(n){return t.subscribe((function(t){return e(t)?n.next(t):void 0}),n.complete)}))}},exports.map=function(e){return function(t){return new s((function(n){return t.subscribe((function(t){return n.next(e(t))}),n.complete)}))}},exports.merge=function(e){return new s((function(t){var n=e.length;if(0===n)return t.complete();var r=e.map((function(e){return e.subscribe(t.next,(function(){0==--n&&t.complete()}))}));return function(){return r.forEach((function(e){return e()}))}}))},exports.skip=function(e){return function(t){return new s((function(n){var r=0;return t.subscribe((function(t){r>=e?n.next(t):r++}),n.complete)}))}},exports.skipSynchronous=function(){return function(e){return new s((function(t){var n={skip:!0},r=e.subscribe((function(e){return n.skip?void 0:t.next(e)}),t.complete);return n.skip=!1,r}))}},exports.switchMap=function(e){return function(t){return new s((function(n){var r=function(){},i=1,o=function(){0==--i&&n.complete()},s=t.subscribe((function(t){r(),i++;var s=e(t);r=s.subscribe((function(e){return n.next(e)}),o)}),o);return function(){r(),s()}}))}},exports.take=function(e){return function(t){return new s((function(n){if(e<1)return n.complete();var r=0,i=t.subscribe((function(t){r<e&&n.next(t),++r>=e&&(i&&i(),n.complete())}),n.complete);return r>=e&&(i(),n.complete()),i}))}},exports.withDefault=function(e){return function(t){return new s((function(n){return n.next(e),t.subscribe(n.next,n.complete)}))}};
//# sourceMappingURL=derive-state.cjs.production.min.js.map

312

dist/derive-state.esm.js

@@ -17,8 +17,2 @@ function _defineProperties(target, props) {

function _inheritsLoose(subClass, superClass) {
subClass.prototype = Object.create(superClass.prototype);
subClass.prototype.constructor = subClass;
subClass.__proto__ = superClass;
}
var ObserverList = /*#__PURE__*/function () {

@@ -63,2 +57,9 @@ function ObserverList() {

_createClass(ObserverList, [{
key: "size",
get: function get() {
return this.observers.size;
}
}]);
return ObserverList;

@@ -70,29 +71,23 @@ }();

var DerivedState = /*#__PURE__*/function () {
function DerivedState(derive) {
var _this = this;
var State = /*#__PURE__*/function () {
function State(initialValue) {
this.observerList = new ObserverList();
this.state = EMPTY;
this.teardown = derive({
next: function next(_next) {
if (_this.observerList.closed) {
throw new Error("Can't set the value of a closed ObservableState");
}
this.teardown = noop;
_this.state = _next;
if (arguments.length >= 1) {
this.state = initialValue;
}
}
_this.observerList.emit(_next);
},
complete: function complete() {
return _this.close();
}
}) || noop; // For synchronous completes
var _proto = State.prototype;
_proto.setValue = function setValue(newState) {
if (this.observerList.closed) {
this.teardown();
throw new Error("Can't set the value of a closed ObservableState");
}
}
var _proto = DerivedState.prototype;
this.state = newState;
this.observerList.emit(newState);
};

@@ -116,2 +111,35 @@ _proto.subscribe = function subscribe(next, complete) {

_proto.pipe = function pipe() {
for (var _len = arguments.length, operators = new Array(_len), _key = 0; _key < _len; _key++) {
operators[_key] = arguments[_key];
}
var firstOp = operators[0],
rest = operators.slice(1);
var first = firstOp(this);
var current = first;
rest.forEach(function (operator) {
current = operator(current);
});
return Object.assign(current, {
kill: function kill() {
return first.close();
}
});
};
_proto.appendTeardown = function appendTeardown(teardown) {
var old = this.teardown;
this.teardown = function () {
old();
teardown();
};
};
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
_proto.hasValue = function hasValue() {

@@ -129,19 +157,11 @@ return this.state !== EMPTY;

_proto.close = function close() {
var _this$teardown;
// On synchronous completes, this.teardown can possibly not be defined yet
(_this$teardown = this.teardown) == null ? void 0 : _this$teardown.call(this);
this.observerList.close();
};
_createClass(DerivedState, [{
_createClass(State, [{
key: "value",
get: function get() {
var _this2 = this;
var _this = this;
return new Promise(function (resolve, reject) {
if (_this2.hasValue()) return resolve(_this2.getValue());
if (_this.hasValue()) return resolve(_this.getValue());
var unsub = _this2.subscribe(function (v) {
var unsub = _this.subscribe(function (v) {
unsub();

@@ -156,39 +176,103 @@ resolve(v);

return DerivedState;
return State;
}();
var State = /*#__PURE__*/function (_DerivedState) {
_inheritsLoose(State, _DerivedState);
var EMPTY = /*#__PURE__*/Symbol('empty');
function State(initialValue) {
var _this3;
var Stateless = /*#__PURE__*/function () {
function Stateless(derive) {
if (derive === void 0) {
derive = noop;
}
var args = arguments;
var capturedObserver;
_this3 = _DerivedState.call(this, function (obs) {
capturedObserver = obs;
this.observerList = new ObserverList();
this.teardown = noop;
this.start = derive;
}
if (args.length >= 1) {
obs.next(initialValue);
}
}) || this;
var _proto = Stateless.prototype;
_this3.next = function (v) {
return capturedObserver.next(v);
_proto.emit = function emit(next) {
this.observerList.emit(next);
};
_proto.subscribe = function subscribe(next, complete) {
var _this = this;
var observer = {
next: next,
complete: complete || noop
};
return _this3;
}
if (this.observerList.closed) {
observer.complete();
return noop;
}
var _proto2 = State.prototype;
var unsub = this.observerList.addObserver(observer);
_proto2.setValue = function setValue(newState) {
this.next(newState);
if (this.observerList.size === 1) {
this.teardown = this.start({
next: function next(v) {
return _this.emit(v);
},
complete: function complete() {
return _this.close();
}
}) || noop;
}
return function () {
unsub();
if (_this.observerList.size === 0) {
_this.teardown();
}
};
};
return State;
}(DerivedState);
var EMPTY = /*#__PURE__*/Symbol('empty');
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
_proto.pipe = function pipe() {
for (var _len = arguments.length, operators = new Array(_len), _key = 0; _key < _len; _key++) {
operators[_key] = arguments[_key];
}
var firstOp = operators[0],
rest = operators.slice(1);
var first = firstOp(this);
var current = first;
rest.forEach(function (operator) {
current = operator(current);
});
return Object.assign(current, {
kill: function kill() {
return first.close();
}
});
};
_proto.capture = function capture() {
var state = new State();
var unsub = this.subscribe(function (n) {
return state.setValue(n);
}, function () {
return state.close();
});
state.appendTeardown(unsub);
return state;
};
return Stateless;
}();
var asStateless = function asStateless(observable) {
return new Stateless(function (obs) {
return observable.subscribe(obs.next, obs.complete);
});
};
var combine = function combine(input) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var active = false;

@@ -230,3 +314,3 @@ var value = Array.isArray(input) ? [] : {};

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var lastValue = EMPTY$1;

@@ -247,3 +331,3 @@ return source.subscribe(function (value) {

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
return source.subscribe(function (value) {

@@ -258,3 +342,3 @@ return filterFn(value) ? obs.next(value) : void 0;

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
return source.subscribe(function (value) {

@@ -268,3 +352,3 @@ return obs.next(mapFn(value));

var merge = function merge(observables) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var activeSubs = observables.length;

@@ -293,18 +377,5 @@

function pipe(source) {
var current = source;
for (var _len = arguments.length, operators = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
operators[_key - 1] = arguments[_key];
}
operators.forEach(function (operator) {
current = operator(current);
});
return current;
}
var skip = function skip(n) {
return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var i = 0;

@@ -324,3 +395,3 @@ return source.subscribe(function (v) {

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var state = {

@@ -340,3 +411,3 @@ skip: true

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
var innerUnsub = function innerUnsub() {

@@ -359,3 +430,4 @@ return void 0;

activeSubs++;
innerUnsub = mapFn(value).subscribe(function (v) {
var inner$ = mapFn(value);
innerUnsub = inner$.subscribe(function (v) {
return obs.next(v);

@@ -374,3 +446,3 @@ }, handleComplete);

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
if (n < 1) {

@@ -406,3 +478,3 @@ return obs.complete();

return function (source) {
return new DerivedState(function (obs) {
return new Stateless(function (obs) {
obs.next(value);

@@ -414,73 +486,3 @@ return source.subscribe(obs.next, obs.complete);

var DerivedStateless = /*#__PURE__*/function () {
function DerivedStateless(derive) {
var _this = this;
this.observerList = new ObserverList();
this.teardown = derive({
next: function next(_next) {
return _this.observerList.emit(_next);
},
complete: function complete() {
return _this.close();
}
}) || noop;
}
var _proto = DerivedStateless.prototype;
_proto.subscribe = function subscribe(next, complete) {
var observer = {
next: next,
complete: complete || noop
};
if (this.observerList.closed) {
observer.complete();
return noop;
}
return this.observerList.addObserver(observer);
};
_proto.close = function close() {
this.teardown();
this.observerList.close();
};
return DerivedStateless;
}();
var Stateless = /*#__PURE__*/function (_DerivedStateless) {
_inheritsLoose(Stateless, _DerivedStateless);
function Stateless() {
var _this2;
var capturedObserver;
_this2 = _DerivedStateless.call(this, function (obs) {
capturedObserver = obs;
}) || this;
_this2.next = function (v) {
return capturedObserver.next(v);
};
return _this2;
}
var _proto2 = Stateless.prototype;
_proto2.emit = function emit(newState) {
this.next(newState);
};
return Stateless;
}(DerivedStateless);
var asStateless = function asStateless(observable) {
return new DerivedStateless(function (obs) {
return observable.subscribe(obs.next, obs.complete);
});
};
export { DerivedState, DerivedStateless, State, Stateless, asStateless, combine, distinctUntilChanged, filter, map, merge, pipe, skip, skipSynchronous, switchMap, take, withDefault };
export { State, Stateless, asStateless, combine, distinctUntilChanged, filter, map, merge, skip, skipSynchronous, switchMap, take, withDefault };
//# sourceMappingURL=derive-state.esm.js.map

17

dist/interface.d.ts
export interface Observable<T> {
subscribe(next: (value: T) => void, complete?: () => void): () => void;
close(): void;
pipe: PipeFn<T>;
}
export interface ObservableState<T> extends Observable<T> {
export interface StateObservable<T> extends Observable<T> {
value: Promise<T>;

@@ -10,2 +11,5 @@ hasValue(): boolean;

}
export interface StatelessObservable<T> extends Observable<T> {
capture(): StateObservable<T>;
}
export interface Observer<T> {

@@ -15,1 +19,12 @@ next: (value: T) => void;

}
export interface Operator<T, R> {
(source: Observable<T>): Observable<R>;
}
interface PipeFn<T> {
<R>(op: Operator<T, R>): Observable<R>;
<S1, R>(op0: Operator<T, S1>, opN: Operator<S1, R>): Observable<R>;
<S1, S2, R>(op0: Operator<T, S1>, op1: Operator<S1, S2>, opN: Operator<S2, R>): Observable<R>;
<S1, S2, S3, R>(op0: Operator<T, S1>, op1: Operator<S1, S2>, op2: Operator<S2, S3>, opN: Operator<S3, R>): Observable<R>;
<S1, S2, S3, S4, R>(op0: Operator<T, S1>, op1: Operator<S1, S2>, op2: Operator<S2, S3>, op3: Operator<S3, S4>, opN: Operator<S4, R>): Observable<R>;
}
export {};

1

dist/internal.d.ts

@@ -8,3 +8,4 @@ import { Observer } from './interface';

close(): void;
get size(): number;
}
export declare const noop: () => undefined;

4

dist/operators/combine.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const combine: <T>(input: { [K in keyof T]: Observable<T[K]>; }) => DerivedState<T>;
export declare const combine: <T>(input: { [K in keyof T]: Observable<T[K]>; }) => Stateless<T>;

4

dist/operators/distinctUntilChanged.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const distinctUntilChanged: <T>(eqFn?: (a: T, b: T) => boolean) => (source: Observable<T>) => DerivedState<T>;
export declare const distinctUntilChanged: <T>(eqFn?: (a: T, b: T) => boolean) => (source: Observable<T>) => Stateless<T>;

4

dist/operators/filter.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const filter: <T>(filterFn: (value: T) => boolean) => (source: Observable<T>) => DerivedState<T>;
export declare const filter: <T>(filterFn: (value: T) => boolean) => (source: Observable<T>) => Stateless<T>;

1

dist/operators/index.d.ts

@@ -6,3 +6,2 @@ export * from './combine';

export * from './merge';
export * from './operators';
export * from './skip';

@@ -9,0 +8,0 @@ export * from './skipSynchronous';

4

dist/operators/map.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const map: <T, R>(mapFn: (value: T) => R) => (source: Observable<T>) => DerivedState<R>;
export declare const map: <T, R>(mapFn: (value: T) => R) => (source: Observable<T>) => Stateless<R>;

4

dist/operators/merge.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const merge: <T>(observables: Observable<T>[]) => DerivedState<T>;
export declare const merge: <T>(observables: Observable<T>[]) => Stateless<T>;

4

dist/operators/skip.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const skip: (n: number) => <T>(source: Observable<T>) => DerivedState<T>;
export declare const skip: (n: number) => <T>(source: Observable<T>) => Stateless<T>;

4

dist/operators/skipSynchronous.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const skipSynchronous: () => <T>(source: Observable<T>) => DerivedState<T>;
export declare const skipSynchronous: () => <T>(source: Observable<T>) => Stateless<T>;

4

dist/operators/switchMap.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const switchMap: <T, R>(mapFn: (value: T) => Observable<R>) => (source: Observable<T>) => DerivedState<R>;
export declare const switchMap: <T, R>(mapFn: (value: T) => Observable<R>) => (source: Observable<T>) => Stateless<R>;

4

dist/operators/take.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const take: (n: number) => <T>(source: Observable<T>) => DerivedState<T>;
export declare const take: (n: number) => <T>(source: Observable<T>) => Stateless<T>;

4

dist/operators/withDefault.d.ts

@@ -1,3 +0,3 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export declare const withDefault: <T>(value: T) => <S>(source: Observable<S>) => DerivedState<T | S>;
export declare const withDefault: <T>(value: T) => <S>(source: Observable<S>) => Stateless<T | S>;

18

dist/state.d.ts

@@ -1,17 +0,17 @@

import { ObservableState, Observer } from './interface';
export declare class DerivedState<T> implements ObservableState<T> {
import { StateObservable, Operator } from './interface';
export declare class State<T> implements StateObservable<T> {
private observerList;
private state;
private teardown;
constructor(derive: (observer: Observer<T>) => void | (() => void));
constructor(initialValue?: T);
setValue(newState: T): void;
subscribe(next: (value: T) => void, complete?: () => void): () => void;
pipe(...operators: Operator<any, any>[]): import("./interface").Observable<any> & {
kill: () => void;
};
appendTeardown(teardown: () => void): void;
close(): void;
hasValue(): boolean;
getValue(): T;
close(): void;
get value(): Promise<T>;
}
export declare class State<T> extends DerivedState<T> {
private next;
constructor(initialValue?: T);
setValue(newState: T): void;
}

19

dist/stateless.d.ts

@@ -1,14 +0,15 @@

import { Observable, ObservableState, Observer } from './interface';
export declare class DerivedStateless<T> implements Observable<T> {
import { StateObservable, Observer, Operator, StatelessObservable } from './interface';
export declare class Stateless<T> implements StatelessObservable<T> {
private observerList;
private teardown;
constructor(derive: (observer: Observer<T>) => void | (() => void));
private start;
constructor(derive?: (observer: Observer<T>) => void | (() => void));
emit(next: T): void;
subscribe(next: (value: T) => void, complete?: () => void): () => void;
close(): void;
pipe(...operators: Operator<any, any>[]): import("./interface").Observable<any> & {
kill: () => void;
};
capture(): StateObservable<T>;
}
export declare class Stateless<T> extends DerivedStateless<T> {
private next;
constructor();
emit(newState: T): void;
}
export declare const asStateless: <T>(observable: ObservableState<T>) => DerivedStateless<unknown>;
export declare const asStateless: <T>(observable: StateObservable<T>) => Stateless<unknown>;

2

package.json
{
"version": "0.1.0-alpha.3",
"version": "0.1.0-alpha.4",
"license": "MIT",

@@ -4,0 +4,0 @@ "main": "dist/index.js",

169

README.md

@@ -5,3 +5,3 @@ # DeriveState

Heavily inspired from RxJS, but while RxJS focuses on asynchronous values, DeriveState focuses on stateful boxes, (aka cells in a spreadsheet) - As if everything were a `BehaviourSubject`, but where you can derive them from other states.
Heavily inspired from RxJS, but while RxJS focuses on asynchronous values, DeriveState focuses on stateful boxes, (aka cells in a spreadsheet) - As if everything were a `BehaviourSubject`, and you create new states deriving them from other states.

@@ -12,4 +12,6 @@ Experimental

## State
```ts
import { State, DerivedState } from 'derive-state';
import { State } from 'derive-state';

@@ -24,44 +26,82 @@ const apples = new State(0);

const squaredApples = new DerivedState(next =>
apples.subscribe(apples => next(apples * apples))
);
squaredApples.subscribe(apples =>
console.log(`We now have ${apples} squared apple(s)`)
);
// Logs "We now have 4 squared apple(s)"
console.log('apples: ' + apples.getValue());
// Logs "apples: 2"
```
// `squaredApples` is a DerivedState, it doesn't have a function `setValue`
// but its state will react to changes from `apples`
apples.setValue(3);
// Logs "We now have 3 apple(s)" "We now have 9 squared apple(s)"
The initial value is optional: if omitted the state will be empty
```ts
import { State } from 'derive-state';
const apples = new State();
apples.subscribe(apples => console.log(`We now have ${apples} apple(s)`));
// Doesn't log anything
// We can't read the value synchronously in this case
expect(() => apples.getValue()).toThrow();
// We have a function that tell us whether it holds a value or not
expect(apples.hasValue()).toBe(false);
// Or we can get a promise for when it finally has a value
apples.value.then(v => console.log(`Promise resolved with ${v}`));
apples.setValue(2);
// Logs "We now have 2 apple(s)" followed by "Promise resolved with 2"
expect(apples.hasValue()).toBe(true);
```
DeriveState also exports some operators to help compose states. Internally, all
of them are using `new DerivedState`
Subscriptions and state can both get cleaned up:
Note that pipe is an external function, where the first parameter is the observable
to throw down the pipeline.
```ts
import { pipe, combine, map } from 'derive-state';
import { State } from 'derive-state';
const pears = new State(10);
const apples = new State(0);
const fruits = pipe(
combine([apples, pears]), // eq. combineLatest in rxjs
map(([apples, pears]) => apples + pears)
const unsub1 = apples.subscribe(
apples => console.log(`We now have ${apples} apple(s)`)
() => console.log("complete")
);
fruits.subscribe(fruits => console.log(`We have ${fruits} fruit(s) in total`));
// Logs "We have 13 fruit(s) in total"
// Logs "We now have 0 apple(s)"
unsub1();
apples.setValue(2);
// Doesn't log anything
apples.subscribe(
apples => console.log(`We now have ${apples} apple(s)`)
() => console.log("complete")
);
// Logs "We now have 2 apple(s)"
apples.close();
// Logs "complete"
// We can't set the value of a closed state.
// As semantically it means this value won't ever change again.
expect(() => apples.setValue(5)).toThrow();
// But we can still read the value
console.log('apples: ' + apples.getValue());
// Logs "apples: 2"
// And subscribe (it will just call back and close the subscription immediately)
apples.subscribe(
apples => console.log(`We now have ${apples} apple(s)`)
() => console.log("complete")
);
// Logs "We now have 2 apple(s)" followed by "complete"
```
For convenience, it also exposes Stateless observables: those that you will only
get updates from new values.
## Stateless
Note that when deriving a state using any of the exposed operators, it will
result in a stateful observable. DeriveState exports a utility to turn a stateful
observable to a stateless:
An stateless observable doesn't hold any value.
It has two main ways it can be used:
### Similar to an event emitter
```ts
import { Stateless, asStateless } from 'derive-state';
import { Stateless } from 'derive-state';

@@ -75,24 +115,63 @@ const clicks = new Stateless();

// Logs "received a click"
```
const totalClicks = pipe(
clicks,
scan(acc => acc + 1, 0) // (scan operator TBD)
### Derived from another observable
```ts
import { Stateless } from 'derive-state';
const apples = new State(2);
const squaredApples = new Stateless(obs => {});
const squaredApples = new Stateless(obs =>
apples.subscribe(apples => obs.next(apples * apples), obs.complete)
);
totalClicks.subscribe(total => console.log(`total clicks: ${total}`));
// Logs "total clicks: 0"
squaredApples.subscribe(apples =>
console.log(`We now have ${apples} squared apple(s)`)
);
// Logs "We now have 4 squared apple(s)"
clicks.emit('click');
// Logs "received a click" "total clicks: 1"
// Equivalent when using `pipe`:
const pipedSquaredApples = apples.pipe(map(apples => apples * apples));
```
const totalClickChanges = asStateless(totalClicks);
totalClickChanges.subscribe(total => console.log('new total clicks: ${total}'));
// Logs nothing
**A stateless is lazy**: Meaning it won't run the derive function until someone subscribes to it.
clicks.emit('click');
// Logs "received a click" "total clicks: 2" "new total clicks: 2"
**A stateless is multicast**: It will share the derive function along all the subscribers in the chain.
totalClickChanges.subscribe(total => console.log('new total clicks: ${total}'));
// Logs nothing
Stateless are designed to make composition easily: This way we can write operators that define their behaviour, and we can compose them easily with `pipe`.
Note that this has an apparent issue:
```ts
const squaredApples = apples.pipe(map(apples => apples * apples));
squaredApples.subscribe(apples =>
console.log(`We now have ${apples} squared apple(s)`)
);
// Logs "We now have 4 squared apple(s)"
squaredApples.subscribe(apples =>
console.log(`We now have ${apples} squared apple(s)`)
);
// Doesn't log anything
```
This is due to the nature of `squaredApples` being stateless and multicast: By the time the second subscriber comes in, `apples` has already emitted its value, so it won't receive it. When `apple` changes, both subscribers will receive the new value.
That's why usually you would `capture` these stateless observables into stateful observables. The trade-off is that while stateless observables get cleaned up when they don't have subscriptions, stateful observables as they hold a value they need cleaning up, that's why you'd call `capture` only after you've applied the composed operator chain
```ts
const pears = new State(10);
// eq. combineLatest in rxjs
const totalFruits = combine([apples, pears])
.pipe(map(([apples, pears]) => apples + pears))
.capture();
totalFruits.subscribe(fruits => console.log(`We now have ${fruits} fruits`));
// Logs "We now have 12 fruits"
totalFruits.subscribe(fruits => console.log(`We now have ${fruits} fruits`));
// Logs "We now have 12 fruits"
```
### Operators

@@ -99,0 +178,0 @@

34

src/interface.ts
export interface Observable<T> {
subscribe(next: (value: T) => void, complete?: () => void): () => void;
close(): void;
pipe: PipeFn<T>;
}
export interface ObservableState<T> extends Observable<T> {
export interface StateObservable<T> extends Observable<T> {
value: Promise<T>;

@@ -12,2 +13,6 @@ hasValue(): boolean;

export interface StatelessObservable<T> extends Observable<T> {
capture(): StateObservable<T>;
}
export interface Observer<T> {

@@ -17,1 +22,28 @@ next: (value: T) => void;

}
export interface Operator<T, R> {
(source: Observable<T>): Observable<R>;
}
interface PipeFn<T> {
<R>(op: Operator<T, R>): Observable<R>;
<S1, R>(op0: Operator<T, S1>, opN: Operator<S1, R>): Observable<R>;
<S1, S2, R>(
op0: Operator<T, S1>,
op1: Operator<S1, S2>,
opN: Operator<S2, R>
): Observable<R>;
<S1, S2, S3, R>(
op0: Operator<T, S1>,
op1: Operator<S1, S2>,
op2: Operator<S2, S3>,
opN: Operator<S3, R>
): Observable<R>;
<S1, S2, S3, S4, R>(
op0: Operator<T, S1>,
op1: Operator<S1, S2>,
op2: Operator<S2, S3>,
op3: Operator<S3, S4>,
opN: Operator<S4, R>
): Observable<R>;
}

4

src/internal.ts

@@ -31,4 +31,8 @@ import { Observer } from './interface';

}
get size() {
return this.observers.size;
}
}
export const noop = () => void 0;

4

src/operators/combine.ts

@@ -1,6 +0,6 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const combine = <T>(input: { [K in keyof T]: Observable<T[K]> }) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
let active = false;

@@ -7,0 +7,0 @@ let value: any = Array.isArray(input) ? [] : {};

4

src/operators/distinctUntilChanged.ts

@@ -1,2 +0,2 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';

@@ -7,3 +7,3 @@

) => (source: Observable<T>) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
let lastValue: T | typeof EMPTY = EMPTY;

@@ -10,0 +10,0 @@ return source.subscribe(value => {

4

src/operators/filter.ts

@@ -1,2 +0,2 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';

@@ -7,3 +7,3 @@

) =>
new DerivedState<T>(obs =>
new Stateless<T>(obs =>
source.subscribe(

@@ -10,0 +10,0 @@ value => (filterFn(value) ? obs.next(value) : void 0),

1

src/operators/index.ts

@@ -6,3 +6,2 @@ export * from './combine';

export * from './merge';
export * from './operators';
export * from './skip';

@@ -9,0 +8,0 @@ export * from './skipSynchronous';

4

src/operators/map.ts

@@ -1,7 +0,7 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const map = <T, R>(mapFn: (value: T) => R) => (source: Observable<T>) =>
new DerivedState<R>(obs =>
new Stateless<R>(obs =>
source.subscribe(value => obs.next(mapFn(value)), obs.complete)
);

4

src/operators/merge.ts

@@ -1,6 +0,6 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const merge = <T>(observables: Observable<T>[]) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
let activeSubs = observables.length;

@@ -7,0 +7,0 @@ if (activeSubs === 0) {

4

src/operators/skip.ts

@@ -1,6 +0,6 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const skip = (n: number) => <T>(source: Observable<T>) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
let i = 0;

@@ -7,0 +7,0 @@ return source.subscribe(v => {

4

src/operators/skipSynchronous.ts

@@ -1,6 +0,6 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const skipSynchronous = () => <T>(source: Observable<T>) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
const state = {

@@ -7,0 +7,0 @@ skip: true,

7

src/operators/switchMap.ts

@@ -1,2 +0,2 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';

@@ -7,3 +7,3 @@

) =>
new DerivedState<R>(obs => {
new Stateless<R>(obs => {
let innerUnsub = (): void => void 0;

@@ -22,3 +22,4 @@ let activeSubs = 1;

activeSubs++;
innerUnsub = mapFn(value).subscribe(v => obs.next(v), handleComplete);
const inner$ = mapFn(value) as Observable<R>;
innerUnsub = inner$.subscribe(v => obs.next(v), handleComplete);
}, handleComplete);

@@ -25,0 +26,0 @@

4

src/operators/take.ts

@@ -1,6 +0,6 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const take = (n: number) => <T>(source: Observable<T>) =>
new DerivedState<T>(obs => {
new Stateless<T>(obs => {
if (n < 1) {

@@ -7,0 +7,0 @@ return obs.complete();

4

src/operators/withDefault.ts

@@ -1,8 +0,8 @@

import { DerivedState } from '../state';
import { Stateless } from '../stateless';
import { Observable } from '../interface';
export const withDefault = <T>(value: T) => <S>(source: Observable<S>) =>
new DerivedState<S | T>(obs => {
new Stateless<S | T>(obs => {
obs.next(value);
return source.subscribe(obs.next, obs.complete);
});

77

src/state.ts

@@ -1,26 +0,21 @@

import { ObservableState, Observer } from './interface';
import { StateObservable, Observer, Operator } from './interface';
import { noop, ObserverList } from './internal';
export class DerivedState<T> implements ObservableState<T> {
export class State<T> implements StateObservable<T> {
private observerList = new ObserverList<T>();
private state: T | typeof EMPTY = EMPTY;
private teardown: () => void;
private teardown: () => void = noop;
constructor(derive: (observer: Observer<T>) => void | (() => void)) {
this.teardown =
derive({
next: next => {
if (this.observerList.closed) {
throw new Error("Can't set the value of a closed ObservableState");
}
this.state = next;
this.observerList.emit(next);
},
complete: () => this.close(),
}) || noop;
constructor(initialValue?: T) {
if (arguments.length >= 1) {
this.state = initialValue!;
}
}
// For synchronous completes
setValue(newState: T) {
if (this.observerList.closed) {
this.teardown();
throw new Error("Can't set the value of a closed ObservableState");
}
this.state = newState;
this.observerList.emit(newState);
}

@@ -44,2 +39,25 @@

}
pipe(...operators: Operator<any, any>[]) {
const [firstOp, ...rest] = operators;
const first = firstOp(this);
let current = first;
rest.forEach(operator => {
current = operator(current);
});
return Object.assign(current, { kill: () => first.close() });
}
appendTeardown(teardown: () => void) {
const old = this.teardown;
this.teardown = () => {
old();
teardown();
};
}
close() {
this.teardown();
this.observerList.close();
}
hasValue() {

@@ -56,7 +74,2 @@ return this.state !== EMPTY;

}
close() {
// On synchronous completes, this.teardown can possibly not be defined yet
this.teardown?.();
this.observerList.close();
}

@@ -77,22 +90,2 @@ get value() {

export class State<T> extends DerivedState<T> {
private next: (value: T) => void;
constructor(initialValue?: T) {
const args = arguments;
let capturedObserver: Observer<T>;
super(obs => {
capturedObserver = obs;
if (args.length >= 1) {
obs.next(initialValue!);
}
});
this.next = (v: T) => capturedObserver!.next(v);
}
setValue(newState: T) {
this.next(newState);
}
}
const EMPTY = Symbol('empty');

70

src/stateless.ts

@@ -1,16 +0,23 @@

import { Observable, ObservableState, Observer } from './interface';
import {
StateObservable,
Observer,
Operator,
StatelessObservable,
} from './interface';
import { noop, ObserverList } from './internal';
import { State } from './state';
export class DerivedStateless<T> implements Observable<T> {
export class Stateless<T> implements StatelessObservable<T> {
private observerList = new ObserverList<T>();
private teardown: () => void;
private teardown: () => void = noop;
private start: (observer: Observer<T>) => void | (() => void);
constructor(derive: (observer: Observer<T>) => void | (() => void)) {
this.teardown =
derive({
next: next => this.observerList.emit(next),
complete: () => this.close(),
}) || noop;
constructor(derive: (observer: Observer<T>) => void | (() => void) = noop) {
this.start = derive;
}
emit(next: T) {
this.observerList.emit(next);
}
subscribe(next: (value: T) => void, complete?: () => void) {

@@ -27,3 +34,16 @@ const observer: Observer<T> = {

return this.observerList.addObserver(observer);
const unsub = this.observerList.addObserver(observer);
if (this.observerList.size === 1) {
this.teardown =
this.start({
next: v => this.emit(v),
complete: () => this.close(),
}) || noop;
}
return () => {
unsub();
if (this.observerList.size === 0) {
this.teardown();
}
};
}

@@ -35,21 +55,25 @@

}
}
export class Stateless<T> extends DerivedStateless<T> {
private next: (value: T) => void;
constructor() {
let capturedObserver: Observer<T>;
super(obs => {
capturedObserver = obs;
pipe(...operators: Operator<any, any>[]) {
const [firstOp, ...rest] = operators;
const first = firstOp(this);
let current = first;
rest.forEach(operator => {
current = operator(current);
});
this.next = (v: T) => capturedObserver!.next(v);
return Object.assign(current, { kill: () => first.close() });
}
emit(newState: T) {
this.next(newState);
capture() {
const state = new State<T>();
const unsub = this.subscribe(
n => state.setValue(n),
() => state.close()
);
state.appendTeardown(unsub);
return state as StateObservable<T>;
}
}
export const asStateless = <T>(observable: ObservableState<T>) =>
new DerivedStateless(obs => observable.subscribe(obs.next, obs.complete));
export const asStateless = <T>(observable: StateObservable<T>) =>
new Stateless(obs => observable.subscribe(obs.next, obs.complete));
dist/operators/operators.d.ts
src/operators/operators.ts
dist/derive-state.cjs.development.js.map

Sorry, the diff of this file is not supported yet

dist/derive-state.cjs.production.min.js.map

Sorry, the diff of this file is not supported yet

dist/derive-state.esm.js.map

Sorry, the diff of this file is not supported yet

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