From 56a50679dee82bacbebf8e9dcb7a9632f90ef7b5 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Sat, 19 Aug 2017 14:54:10 +0200
Subject: [PATCH] reactive sequence works now

---
 experiments/nextgen.nim | 67 ++++++++++++++++++++++++++++---------
 src/karax.nim           | 18 ++++++++++
 src/reactive.nim        | 73 +++++++++++++++++++++++++++++++++++------
 src/vdom.nim            |  4 +++
 4 files changed, 137 insertions(+), 25 deletions(-)

diff --git a/experiments/nextgen.nim b/experiments/nextgen.nim
index fb95a6b..4f955aa 100644
--- a/experiments/nextgen.nim
+++ b/experiments/nextgen.nim
@@ -2,24 +2,61 @@
 import vdom, kdom, vstyles, karax, karaxdsl, jdict, jstrutils, reactive
 
 type
-  User = ref object
+  User = ref object of ReactiveBase
     firstname, lastname: cstring
 
-var gu = @[newReactive(User(firstname: "Some", lastname: "Body")),
-           newReactive(User(firstname: "Some", lastname: "One")),
-           newReactive(User(firstname: "Some", lastname: "Two"))]
+var gu = newRSeq(@[ (User(firstname: "Some", lastname: "Body")),
+                    (User(firstname: "Some", lastname: "One")),
+                    (User(firstname: "Some", lastname: "Two"))])
 var clicks = 0
 
-proc renderUser(u: Reactive[User]): VNode {.track.} =
-  result = buildHtml(button):
-    text u.now.firstname & " " & u.now.lastname
-    proc onclick(ev: Event; n: VNode) =
-      inc clicks
-      u <- User(firstname: "Another", lastname: &clicks)
+discard """
+  # Text gets a *reactive* string in the first place!
+  # Text can register and knows how to update itself!
+  proc toReact(): RString =
+    observe(u):
+      u.firstname & u.lastname
 
-proc main(): VNode =
-  result = buildHtml(tdiv):
-    for i in 0..high(gu):
-      renderUser(gu[i])
+  let t = text(u.firstname & " " & u.lastname)
+  observe(u, t.update(u.firstname & " " & u.lastname))
+  t
+"""
 
-setInitializer(main)
+proc renderUser(u: User): VNode = #{.track.} =
+  proc inner(u: User): VNode =
+    result = buildHtml(tdiv):
+      text u.firstname & " " & u.lastname
+      button:
+        text "(X)"
+        proc onclick(ev: Event; n: VNode) =
+          #u.firstname = "kfdj"
+          #u.lastname = &clicks
+          #notifyObservers(u)
+          gu.deleteElem(u)
+
+  result = inner(u)
+  doTrack(u, result, inner(u))
+
+template vmap(x: RSeq; elem, f: untyped): VNode =
+  let tmp = buildHtml(elem):
+    for i in 0..<len(x):
+      f(x[i])
+  doTrackResize(x, tmp, f(x[pos]))
+  tmp
+
+proc main(gu: RSeq[User]): VNode = #{.track.} =
+  proc inner(gu: RSeq[User]): VNode =
+    result = buildHtml(tdiv):
+      vmap(gu, tdiv, renderUser)
+      tdiv:
+        button:
+          text "Add User"
+          proc onclick(ev: Event; n: VNode) =
+            inc clicks
+            gu.add User(firstname: "Added", lastname: &clicks)
+  result = inner(gu)
+  doTrack(gu, result, inner(gu))
+
+proc init(): VNode = main(gu)
+
+setInitializer(init)
diff --git a/src/karax.nim b/src/karax.nim
index 3f53405..3df1edb 100644
--- a/src/karax.nim
+++ b/src/karax.nim
@@ -514,6 +514,24 @@ when defined(stats):
     result = m + 1
     inc total
 
+proc runDel*(kxi: KaraxInstance; parent: VNode; position: int) =
+  detach(parent[position])
+  let current = parent.dom
+  kxi.addPatch(pkRemove, current, current.childNodes[position], nil)
+  parent.delete(position)
+  applyPatch(kxi)
+
+proc runIns*(kxi: KaraxInstance; parent, kid: VNode; position: int) =
+  let current = parent.dom
+  if position >= parent.len:
+    kxi.addPatch(pkAppend, current, nil, kid)
+    parent.add(kid)
+  else:
+    let before = current.childNodes[position]
+    kxi.addPatch(pkInsertBefore, current, before, kid)
+    parent.insert(kid, position)
+  applyPatch(kxi)
+
 proc runDiff*(kxi: KaraxInstance; oldNode, newNode: VNode) =
   let olddom = oldNode.dom
   discard diff(newNode, oldNode, nil, olddom, kxi)
diff --git a/src/reactive.nim b/src/reactive.nim
index a1782f0..4fcc851 100644
--- a/src/reactive.nim
+++ b/src/reactive.nim
@@ -32,7 +32,7 @@ type
     s: seq[T]
     L: RInt
 
-proc addSink[T](x: Reactive[T]; sink: proc(msg: Message; pos: int)) =
+proc addSink(x: ReactiveBase; sink: proc(msg: Message; pos: int)) =
   x.sinks.add sink
 
 proc addSink(x: ReactiveBase; key: cstring; sink: proc(msg: Message; pos: int)) =
@@ -88,7 +88,7 @@ proc `<-`*[T](x: Reactive[T], val: T) =
   x.broadcast(Mark)
   x.broadcast(Changed)
 
-proc changed*(x: ReactiveBase) =
+proc notifyObservers*(x: ReactiveBase) =
   x.broadcast(Mark)
   x.broadcast(Changed)
 
@@ -125,10 +125,17 @@ proc newRSeq*[T](data: seq[T]): RSeq[T] =
   for i in 0..high(data):
     result.s[i] = data[i]
 
-proc `[]=`[T](x: RSeq[T]; index: int; v: T) =
+proc `[]=`*[T](x: RSeq[T]; index: int; v: T) =
   x.s[index] = v
 
-proc `[]`[T](x: RSeq[T]; index: int): T = x.s[index]
+proc `[]`*[T](x: RSeq[T]; index: int): T = x.s[index]
+proc len*[T](x: RSeq[T]): int = x.s.len
+
+proc add*[T](x: RSeq[T]; y: T) =
+  let position = x.s.len
+  x.s.add(y)
+  x.broadcast(Mark)
+  x.broadcast(Inserted, position)
 
 proc insert*[T](x: RSeq[T]; y: T; position = 0) =
   x.s.insert(y, position)
@@ -140,6 +147,16 @@ proc delete*[T](x: RSeq[T]; position = 0) =
   x.broadcast(Mark)
   x.broadcast(Deleted, position)
 
+proc deleteElem*[T](x: RSeq[T]; y: T) =
+  var position = -1
+  for i in 0..<x.len:
+    if x[i] == y:
+      position = i; break
+  if position >= 0:
+    x.s.delete(position)
+    x.broadcast(Mark)
+    x.broadcast(Deleted, position)
+
 proc map*[T, U](x: RSeq[T], f: proc(x: T): U): RSeq[U] =
   let xl = x.L.value
   let res = newRSeq[U](xl)
@@ -159,24 +176,60 @@ proc map*[T, U](x: RSeq[T], f: proc(x: T): U): RSeq[U] =
 import macros
 
 template trackImpl(r: ReactiveBase; key: cstring; a, b: untyped) =
-  when r is Reactive:
+  when r is ReactiveBase:
     addSink r, key, proc(m: Message; pos: int) =
       if m == Changed:
         runDiff(kxi, a, b)
 
+template doTrack*(r: ReactiveBase; a, b: untyped) {.dirty.} =
+  bind addSink, Message, RSeq, Changed, Deleted, Inserted
+  addSink r, proc(m: Message; pos: int) =
+    #when r is RSeq:
+    #echo "Message: ", m, " ", pos
+    if m == Changed: karax.runDiff(kxi, a, b)
+
+template doTrackResize*(r: ReactiveBase; a, b: untyped) {.dirty.} =
+  bind addSink, Message, RSeq, Changed, Deleted, Inserted
+  addSink r, proc(m: Message; pos: int) =
+    #when r is RSeq:
+    #echo "Message: ", m, " ", pos
+    case m
+    of Deleted: karax.runDel(kxi, a, pos)
+    of Inserted:
+      karax.runIns(kxi, a, b, pos)
+    else: discard
+
+template notifyImpl(r: untyped) =
+  when r is ReactiveBase:
+    notifyObservers(r)
+
+proc root(n: NimNode): NimNode =
+  result = n
+  while result.kind in {nnkDotExpr, nnkBracketExpr}: result = result[0]
+
+proc analyse(n: NimNode; paramList: seq[NimNode]): NimNode =
+  result = n
+  #if n.kind in {nnkAsgn, nnkFastAsgn}:
+  #
+  #   n[0]
+  #else:
+  #  recurse()
+
 macro track*(procDef: untyped): untyped =
   let params = params(procDef)
   let key = lineInfo(procDef)
   var call = newCall(procDef.name)
   var trackings = newStmtList()
-  for b in procDef.body: trackings.add b
+  var paramList: seq[NimNode] = @[]
   for j in 1..<params.len:
     let x = params[j]
     expectKind x, nnkIdentDefs
-    for i in 0..x.len-3:
-      let param = x[i]
-      call.add param
-      trackings.add getAst(trackImpl(param, key, ident"result", call))
+    for i in 0..x.len-3: paramList.add(x[i])
+
+  for b in procDef.body: trackings.add analyse(b, paramList)
+  for param in paramList:
+    call.add param
+    trackings.add getAst(trackImpl(param, key, ident"result", call))
 
   result = copyNimTree(procDef)
   result.body = trackings
diff --git a/src/vdom.nim b/src/vdom.nim
index d055b50..bf84cb8 100644
--- a/src/vdom.nim
+++ b/src/vdom.nim
@@ -224,6 +224,10 @@ proc len*(x: VNode): int = x.kids.len
 proc `[]`*(x: VNode; idx: int): VNode = x.kids[idx]
 proc `[]=`*(x: VNode; idx: int; y: VNode) = x.kids[idx] = y
 proc add*(parent, kid: VNode) = parent.kids.add kid
+proc delete*(parent: VNode; position: int) =
+  parent.kids.delete(position)
+proc insert*(parent, kid: VNode; position: int) =
+   parent.kids.insert(kid, position)
 proc newVNode*(kind: VNodeKind): VNode = VNode(kind: kind, index: -1)
 
 proc tree*(kind: VNodeKind; kids: varargs[VNode]): VNode =