From f0e2d41fdee293a14b37b92fe1995ece556e6c32 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Mon, 17 Apr 2017 09:39:13 +0200
Subject: [PATCH] next step to get stateful components

---
 experiments/example.nim    |   1 -
 experiments/oldwidgets.nim |  48 ++++++++++++++++
 src/components.nim         | 111 ++++++++++++++++++++++++-------------
 src/karax.nim              |  15 ++---
 4 files changed, 126 insertions(+), 49 deletions(-)

diff --git a/experiments/example.nim b/experiments/example.nim
index 78dcaae..61235f8 100644
--- a/experiments/example.nim
+++ b/experiments/example.nim
@@ -10,7 +10,6 @@ proc carousel*(key: VKey): VNode {.component.} =
 
   proc next(ev: Event; n: VNode) =
     counter = (counter + 1) mod images.len
-    markDirty key
 
   result = buildHtml(tdiv(key=key)):
     text images[counter]
diff --git a/experiments/oldwidgets.nim b/experiments/oldwidgets.nim
index 023dc98..c947d7f 100644
--- a/experiments/oldwidgets.nim
+++ b/experiments/oldwidgets.nim
@@ -201,3 +201,51 @@ proc visibleKeys(e: Node; a, b: var VKey; h, count: var int) =
   else:
     for i in 0..<e.len:
       visibleKeys(e[i], a, b, h, count)
+
+template toState(x): untyped = "state" & x
+proc accessState(sv: string): NimNode {.compileTime.} =
+  newTree(nnkBracketExpr, newIdentNode(sv), newIdentNode("key"))
+
+proc stateDecl(n: NimNode; names: TableRef[string, bool]; decl, init: NimNode) =
+  case n.kind
+  of nnkVarSection, nnkLetSection:
+    for c in n:
+      expectKind c, nnkIdentDefs
+      let typ = c[^2]
+      let val = c[^1]
+      let usedType = if typ.kind != nnkEmpty: typ else: val
+      if usedType.kind == nnkEmpty:
+        error("cannot determine the variable's type", c)
+      for i in 0 .. c.len-3:
+        let v = $c[i]
+        let sv = toState v
+        decl.add quote do:
+          var `sv` = newJDict[VKey, `usedType`]()
+        if val.kind != nnkEmpty:
+          init.add newTree(nnkAsgn, accessState(sv), val)
+        names[v] = true
+  of nnkStmtList, nnkStmtListExpr:
+    for x in n: stateDecl(x, names, decl, init)
+  of nnkDo:
+    stateDecl(n.body, names, decl, init)
+  of nnkCommentStmt: discard
+  else:
+    error("invalid 'state' declaration", n)
+
+proc doState(n: NimNode; names: TableRef[string, bool];
+             decl, init: NimNode): NimNode =
+  result = n
+  case n.kind
+  of nnkCallKinds:
+    # handle 'state' declaration and remove it from the AST:
+    if n.len == 2 and repr(n[0]) == "state":
+      stateDecl(n[1], names, decl, init)
+      result = newTree(nnkEmpty)
+  of nnkSym, nnkIdent:
+    let v = $n
+    if v in names:
+      let sv = toState v
+      result = accessState(sv)
+  else:
+    for i in 0..<n.len:
+      result[i] = doState(n[i], names, decl, init)
diff --git a/src/components.nim b/src/components.nim
index 54ac8b6..f86cd14 100644
--- a/src/components.nim
+++ b/src/components.nim
@@ -2,6 +2,32 @@
 
 import macros, jdict, dom, vdom, tables, strutils
 
+type
+  StateDict*[V] = ref object
+
+proc `[]`*[V](d: StateDict[V], k: VKey): V {.importcpp: "#[#]".}
+proc put[V](d: StateDict[V], k: VKey, v: V) {.importcpp: "#[#] = #".}
+
+proc contains*[V](d: StateDict[V], k: VKey): bool {.importcpp: "#.hasOwnProperty(#)".}
+proc del*[V](d: StateDict[V], k: VKey) {.importcpp: "delete #[#]".}
+
+proc newStateDict*[V](): StateDict[V] {.importcpp: "{@}".}
+
+var
+  dirty = newStateDict[bool]()
+  someDirty*: bool
+
+proc markDirty*(key: VKey) =
+  dirty.put(key, true)
+  someDirty = true
+
+proc unmarkDirty*(key: VKey) = dirty.del key
+proc isDirty*(key: VKey): bool = dirty.contains(key)
+
+proc `[]=`*[V](d: StateDict[V], k: VKey, v: V) =
+  d.put(k, v)
+  markDirty(k)
+
 var
   vcomponents* = newJDict[cstring, proc(args: seq[VNode]): VNode]()
   dcomponents* = newJDict[cstring, proc(args: seq[VNode]): Node]()
@@ -30,52 +56,50 @@ proc addTags() {.compileTime.} =
 static:
   addTags()
 
-template toState(x): untyped = "state" & x
-proc accessState(sv: string): NimNode {.compileTime.} =
-  newTree(nnkBracketExpr, newIdentNode(sv), newIdentNode("key"))
-
-proc stateDecl(n: NimNode; names: TableRef[string, bool]; decl, init: NimNode) =
+proc stateDecl(n: NimNode; names: TableRef[string, bool]) =
   case n.kind
   of nnkVarSection, nnkLetSection:
     for c in n:
       expectKind c, nnkIdentDefs
-      let typ = c[^2]
-      let val = c[^1]
-      let usedType = if typ.kind != nnkEmpty: typ else: val
-      if usedType.kind == nnkEmpty:
-        error(c, "cannot determine the variable's type")
       for i in 0 .. c.len-3:
         let v = $c[i]
-        let sv = toState v
-        decl.add quote do:
-          var `sv` = newJDict[VKey, `usedType`]()
-        if val.kind != nnkEmpty:
-          init.add newTree(nnkAsgn, accessState(sv), val)
         names[v] = true
   of nnkStmtList, nnkStmtListExpr:
-    for x in n: stateDecl(x, names, decl, init)
+    for x in n: stateDecl(x, names)
   of nnkDo:
-    stateDecl(n.body, names, decl, init)
-  of nnkCommentStmt: discard
-  else:
-    error(n, "invalid 'state' declaration")
+    stateDecl(n.body, names)
+  else: discard
 
-proc doState(n: NimNode; names: TableRef[string, bool]; decl, init: NimNode): NimNode =
+proc accessesState(n: NimNode; names: TableRef[string, bool]): bool =
+  case n.kind
+  of nnkSym, nnkIdent:
+    result = $n in names
+  of nnkBracketExpr, nnkDotExpr:
+    result = accessesState(n[0], names)
+  else:
+    for i in 0..<n.len:
+      if accessesState(n[i], names): return true
+
+proc doState(n: NimNode; names: TableRef[string, bool];
+             outer: NimNode): NimNode =
   result = n
   case n.kind
   of nnkCallKinds:
-    # handle 'state' declaration and remove it from the AST:
+    # handle 'state' declaration and move it to the outer block:
     if n.len == 2 and repr(n[0]) == "state":
-      stateDecl(n[1], names, decl, init)
-      result = newTree(nnkEmpty)
-  of nnkSym, nnkIdent:
-    let v = $n
-    if v in names:
-      let sv = toState v
-      result = accessState(sv)
+      stateDecl(n[1], names)
+      outer.add n[1]
+      result = newEmptyNode()
+  of nnkAsgn, nnkFastAsgn:
+    if accessesState(n[0], names):
+      result = newStmtList(n, newCall(bindSym"markDirty", newIdentNode"key"))
   else:
     for i in 0..<n.len:
-      result[i] = doState(n[i], names, decl, init)
+      result[i] = doState(n[i], names, outer)
+
+proc compBody(body, outer: NimNode): NimNode =
+  var names = newTable[string, bool]()
+  result = doState(body, names, outer)
 
 proc unpack(symbolicType: NimNode; index: int): NimNode {.compileTime.} =
   #let t = symbolicType.getTypeImpl
@@ -114,7 +138,7 @@ macro component*(prc: untyped): untyped =
   for i in 0..6: n.add prc[i].copyNimTree
   expectKind(n, nnkProcDef)
   if n[0].kind == nnkEmpty:
-    error("please pass a non anonymous proc")
+    error("please pass a non anonymous proc", n[0])
   let name = n[0]
   let params = params(n)
   let rettype = repr params[0]
@@ -124,7 +148,7 @@ macro component*(prc: untyped): untyped =
   elif rettype == "Node":
     isvirtual = ComponentKind.Node
   else:
-    error "component must return VNode or Node"
+    error "component must return VNode or Node", params[0]
   let realName = if name.kind == nnkPostfix: name[1] else: name
   let nn = $realName
   n[0] = ident("inner" & nn)
@@ -138,6 +162,9 @@ macro component*(prc: untyped): untyped =
       unpackCall.add unpack(typ, counter)
       inc counter
 
+  let outer = newTree(nnkStmtList)
+  discard compBody(n.body, outer)
+
   template vwrapper(pname, unpackCall) {.dirty.} =
     proc pname(args: seq[VNode]): VNode =
       unpackCall
@@ -154,20 +181,30 @@ macro component*(prc: untyped): untyped =
     bind jdict.`[]=`
     `[]=`(dcomponents, cstring(key), val)
 
-  result = newTree(nnkStmtList, n)
+  outer.add n
+  #outer.add body
+  outer.add unpackCall
+  result = newTree(nnkStmtList)
   if isvirtual == ComponentKind.VNode:
-    result.add getAst(vwrapper(newname name, unpackCall))
+    result.add getAst(vwrapper(newname name, outer))
     result.add getAst(vregister(newLit(nn), realName))
   else:
-    result.add getAst(dwrapper(newname name, unpackCall))
+    result.add getAst(dwrapper(newname name, outer))
     result.add getAst(dregister(newLit(nn), realName))
   allcomponents[nn] = isvirtual
   when defined(debugKaraxDsl):
     echo repr result
 
 when isMainModule:
-  proc public*(x, y: int, b: bool; s: cstring): VNode {.component.} =
-    discard
+  proc public*(key: VKey; x, y: int, b: bool; s: cstring): VNode {.component.} =
+    state:
+      var foo = 89
+
+    proc callback() =
+      foo = 78
+
+    let cc = callback
+
   proc private(x, y: int, b: bool; s: cstring): VNode {.component.} =
     discard
 
diff --git a/src/karax.nim b/src/karax.nim
index 09ec20c..1908d6f 100644
--- a/src/karax.nim
+++ b/src/karax.nim
@@ -116,8 +116,6 @@ proc same(n: VNode, e: Node): bool =
 var
   dorender: proc (): VNode {.closure.}
   currentTree: VNode
-  dirty = newJDict[cstring, bool]()
-  dirtyCount: int
 
 proc replaceById(id: cstring; newTree: Node) =
   let x = document.getElementById(id)
@@ -151,14 +149,9 @@ proc equalsTree(a, b: VNode): bool =
   else:
     result = eq(a, b)
 
-proc markDirty*(key: VKey) =
-  dirty[&key] = true
-  inc dirtyCount
-
 proc updateDirtyElements(parent, current: Node, newNode: VNode) =
-  if newNode.key >= 0 and dirty.contains(&newNode.key):
-    dirty.del(&newNode.key)
-    dec dirtyCount
+  if newNode.key >= 0 and isDirty(newNode.key):
+    unmarkDirty(newNode.key)
     let n = vnodeToDom(newNode)
     if parent == nil:
       replaceById("ROOT", n)
@@ -241,9 +234,9 @@ proc dodraw() =
     let olddom = document.getElementById("ROOT")
     updateElement(nil, olddom, newtree, currentTree)
     #assert same(newtree, document.getElementById("ROOT"))
-    if dirtyCount > 0:
+    if someDirty:
       updateDirtyElements(nil, olddom, newtree)
-      dirtyCount = 0
+      someDirty = false
     currentTree = newtree
   # now that it's part of the DOM, give it the focus:
   if toFocus != nil: