Family Day update

Task/Stack/Crystal/stack.crystal

@@ -0,0 +1,8 @@
+stack = [] of Int32
+(1..10).each do |x|
+  stack.push x
+end
+
+10.times do
+  puts stack.pop
+end

Task/Stack/Ol/stack-1.ol

@@ -0,0 +1,42 @@
+(define stack #null)
+(print "stack is: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* pushing 1")
+(define stack (cons 1 stack))
+(print "stack is: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* pushing 2")
+(define stack (cons 2 stack))
+(print "stack is: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* pushing 3")
+(define stack (cons 3 stack))
+(print "stack is: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* poping")
+(define-values (value stack) (uncons stack #f))
+(print "value: " value)
+(print "stack: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* poping")
+(define-values (value stack) (uncons stack #f))
+(print "value: " value)
+(print "stack: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* poping")
+(define-values (value stack) (uncons stack #f))
+(print "value: " value)
+(print "stack: " stack)
+(print "is stack empty: " (eq? stack #null))
+
+(print "* poping")
+(define-values (value stack) (uncons stack #f))
+(print "value: " value)
+(print "stack: " stack)
+(print "is stack empty: " (eq? stack #null))

Task/Stack/Ol/stack-2.ol

@@ -0,0 +1,37 @@
+(fork-server 'stack (lambda ()
+   (let this ((me '()))
+      (let*((envelope (wait-mail))
+            (sender msg envelope))
+         (case msg
+            (['empty]
+               (mail sender (null? me))
+               (this me))
+            (['push value]
+               (this (cons value me)))
+            (['pop]
+               (cond
+                  ((null? me)
+                     (mail sender #false)
+                     (this me))
+                  (else
+                     (mail sender (car me))
+                     (this (cdr me))))))))))
+(define (push value)
+   (mail 'stack ['push value]))
+(define (pop)
+   (interact 'stack ['pop]))
+(define (empty)
+   (interact 'stack ['empty]))
+
+(for-each (lambda (n)
+      (print "pushing " n)
+      (push n))
+   (iota 5 1)) ; '(1 2 3 4 5)
+
+(let loop ()
+   (print "is stack empty: " (empty))
+   (unless (empty)
+      (begin
+         (print "popping value, got " (pop))
+         (loop))))
+(print "done.")

Task/Stack/Pike/stack.pike

@@ -0,0 +1,6 @@
+object s = ADT.Stack();
+s->push("a");
+s->push("b");
+write("top: %O, pop1: %O, pop2: %O\n",
+      s->top(), s->pop(), s->pop());
+s->reset(); // Empty the stack