Add tasks for all the new languages

Task/Singly-linked-list-Element-insertion/Axe/singly-linked-list-element-insertion.axe

@@ -0,0 +1,5 @@
+Lbl INSERT
+{r₁+2}ʳ→{r₂+2}ʳ
+r₂→{r₁+2}ʳ
+r₁
+Return

Task/Singly-linked-list-Element-insertion/EchoLisp/singly-linked-list-element-insertion.echolisp

@@ -0,0 +1,11 @@
+(define (insert-after lst target item)
+    (when (null? lst) (error "cannot insert in" null))
+    (let [(sub-list (member target lst))]
+        (if sub-list (set-cdr! sub-list (cons item (cdr sub-list))) ; make chirurgy if found
+        (nconc lst item)))) ; else append item
+
+(define L '(a b))
+(insert-after L 'a 'c)
+    L  → (a c b)
+(insert-after L 'x 'y)
+    L → (a c b y)

Task/Singly-linked-list-Element-insertion/Nim/singly-linked-list-element-insertion.nim

@@ -0,0 +1,17 @@
+type Node[T] = ref object
+  next: Node[T]
+  data: T
+
+proc newNode[T](data: T): Node[T] =
+  Node[T](data: data)
+
+var a = newNode 12
+var b = newNode 13
+var c = newNode 14
+
+proc insertAppend(a, n: var Node) =
+  n.next = a.next
+  a.next = n
+
+a.insertAppend(b)
+b.insertAppend(c)

Task/Singly-linked-list-Element-insertion/Oforth/singly-linked-list-element-insertion.oforth

@@ -0,0 +1,16 @@
+Collection Class new: LinkedList(data, mutable next)
+
+LinkedList method: initialize   := next := data ;
+LinkedList method: data   @data ;
+LinkedList method: next   @next ;
+LinkedList method: add(e) e @next LinkedList new := next ;
+
+LinkedList method: forEachNext
+   dup ifNull: [ drop self ]
+   dup 1 ifEq: [ drop false return ]
+   dup next dup ifNull: [ drop 1 ]
+   swap data true ;
+
+: testLink  LinkedList new($A, null) dup add($B) dup add($C) ;
+
+testLink println

Task/Singly-linked-list-Element-insertion/Sidef/singly-linked-list-element-insertion.sidef

@@ -0,0 +1,18 @@
+func insert_after(a,b) {
+    b{:next} = a{:next};
+    a{:next} = b;
+}
+
+var B = Hash.new(
+    data => 3,
+    next => nil,    # not a circular list
+);
+var A = Hash.new(
+    data => 1,
+    next => B,
+);
+var C = Hash.new(
+    data => 2,
+);
+
+insert_after(A, C);