Add Var.now

When interfacing with non Rx stuff, this can be handy to get the current
value of a Var.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/rx.ts b/src/rx.ts
index 958abcb..df69d31 100644
--- a/src/rx.ts
+++ b/src/rx.ts
@@ -270,12 +270,18 @@ export class Var<A> extends Rx<A> {
   readonly type: 'Var'
   readonly id: string
   readonly update: (f: (value: A) => A) => void
+  readonly now: () => A
 
-  constructor(id: string, update: (v: Var<A>) => ((f: ((value: A) => A)) => void)) {
+  constructor(
+      id: string,
+      update: (v: Var<A>) => ((f: ((value: A) => A)) => void),
+      now: (v: Var<A>) => (() => A)
+  ) {
     super()
     this.id = id
     this.type = 'Var'
     this.update = update(this)
+    this.now = now(this)
   }
 }
 
@@ -350,7 +356,11 @@ class State {
   }
 
   register<A>(initValue: A) {
-    const v = new Var(this.varCounter.toString(), v => (f => this.update(v, f)))
+    const v = new Var(
+        this.varCounter.toString(),
+        v => (f => this.update(v, f)),
+        v => () => this.get(v)
+    )
     this.varCounter += BigInt(1)
     this.state[v.id] = {
       value: initValue,