rewritten diff algorithm

tests/difftest.nim

@@ -0,0 +1,37 @@
+
+include "../src/karax"
+import "../src/karaxdsl"
+
+proc doDiff(a, b: VNode) =
+  var patches: seq[Patch] = @[]
+  echo diff(nil, vnodeToDom(a, kxi), b, a, patches, kxi)
+  echo patches
+
+proc testAppend() =
+  let a = buildHtml(tdiv):
+    ul:
+      li: text "A"
+      li: text "B"
+  let b = buildHtml(tdiv):
+    ul:
+      li: text "A"
+      li: text "B"
+      li: text "C"
+  doDiff(a, b)
+
+proc testInsert() =
+  let a = buildHtml(tdiv):
+    ul:
+      li: text "A"
+      li: text "C"
+  let b = buildHtml(tdiv):
+    ul:
+      li: text "A"
+      li: text "B"
+      li: text "C"
+  doDiff(a, b)
+
+kxi = KaraxInstance(rootId: cstring"ROOT", renderer: proc (): VNode = discard)
+
+#testAppend()
+testInsert()