Add tasks for all the new languages

Task/Visualize-a-tree/Lingo/visualize-a-tree-1.lingo

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+-- parent script "TreeItem"
+-- (minimal implementation with direct property access)
+
+property name
+property children
+
+on new (me, itemName)
+  me.name = itemName
+  me.children = []
+  return me
+end
+
+on addChild (me, child)
+  me.children.add(child)
+end
+
+-- print a tree
+on printTree (me, treeItem, indent)
+  if voidP(treeItem) then treeItem = me
+  if voidP(indent) then indent = ""
+  put indent&treeItem.name
+  repeat with c in treeItem.children
+    me.printTree(c, indent&"  ")
+  end repeat
+end

Task/Visualize-a-tree/Lingo/visualize-a-tree-2.lingo

@@ -0,0 +1,17 @@
+-- create a tree
+root = script("TreeItem").new("root")
+a = script("TreeItem").new("a")
+root.addChild(a)
+b = script("TreeItem").new("b")
+root.addChild(b)
+a1 = script("TreeItem").new("a1")
+a.addChild(a1)
+a11 = script("TreeItem").new("a11")
+a1.addChild(a11)
+a12 = script("TreeItem").new("a12")
+a1.addChild(a12)
+b1 = script("TreeItem").new("b1")
+b.addChild(b1)
+
+-- print the tree
+root.printTree()

Task/Visualize-a-tree/Nim/visualize-a-tree.nim

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+import strutils
+
+type
+  Node[T] = ref TNode[T]
+  TNode[T] = object
+    data: T
+    left, right: Node[T]
+
+proc n[T](data: T; left, right: Node[T] = nil): Node[T] =
+  Node[T](data: data, left: left, right: right)
+
+proc indent[T](n: Node[T]): seq[string] =
+  if n == nil: return @["-- (null)"]
+
+  result = @["--" & $n.data]
+
+  for a in indent n.left: result.add "  |" & a
+
+  let r = indent n.right
+  result.add "  `" & r[0]
+  for a in r[1..r.high]: result.add "   " & a
+
+let tree = 1.n(2.n(4.n(7.n),5.n),3.n(6.n(8.n,9.n)))
+
+echo tree.indent.join("\n")

Task/Visualize-a-tree/Phix/visualize-a-tree-1.phix

@@ -0,0 +1,40 @@
+function rand_tree(integer low, integer high)
+    for i=1 to 2 do
+        integer v = rand(high-low+1)-1+low
+        if v!=low
+        and v!=high then
+            return {v,rand_tree(low,v),rand_tree(v,high)}
+        end if
+    end for
+    return 0
+end function
+
+object tree = rand_tree(0,20)   -- (can be 0, ~1% chance)
+
+constant Horizontal = #C4,
+         Horizontals = "\#C4",
+         TopLeft = #DA,
+         Vertical = #B3,
+         BtmLeft = #C0
+
+procedure visualise_tree(object tree, string root=Horizontals)
+    if atom(tree) then
+        puts(1,"<empty>\n")
+    else
+        object {v,l,r} = tree
+        integer g = root[$]
+        if sequence(l) then
+            root[$] = iff(g=TopLeft or g=Horizontal?' ':Vertical)
+            visualise_tree(l,root&TopLeft)
+        end if
+        root[$] = g
+        puts(1,root)
+        ?v
+        if sequence(r) then
+            root[$] = iff(g=TopLeft?Vertical:' ')
+            visualise_tree(r,root&BtmLeft)
+        end if
+    end if
+end procedure
+
+visualise_tree(tree)

Task/Visualize-a-tree/Phix/visualize-a-tree-2.phix

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+pp(tree,{pp_Nest,10})

Task/Visualize-a-tree/Sidef/visualize-a-tree.sidef

@@ -0,0 +1,21 @@
+func visualize_tree(tree, label, children,
+                    indent = '',
+                    mids = ['├─', '│ '],
+                    ends = ['└─', '  '],
+) {
+    func visit(node, pre) {
+        gather {
+            take(pre[0] + label(node))
+            var chldn = children(node)
+            var end = chldn.end
+            chldn.each_kv { |i, child|
+                if (i == end) { take(visit(child, [pre[1]] ~X+ ends)) }
+                else          { take(visit(child, [pre[1]] ~X+ mids)) }
+            }
+        }
+    }
+    visit(tree, [indent] * 2)
+}
+
+var tree = 'root':['a':['a1':['a11':[]]],'b':['b1':['b11':[]],'b2':[],'b3':[]]]
+say visualize_tree(tree, { .first }, { .second }).flatten.join("\n")