Data commit

Task/Happy-numbers/Lambdatalk/happy-numbers.lambdatalk

@@ -0,0 +1,30 @@
+{def happy
+ {def happy.sum
+  {lambda {:n}
+   {if {= {W.length :n} 1}
+    then {pow {W.first :n} 2}
+    else {+ {pow {W.first :n} 2}
+            {happy.sum {W.rest :n}}}}}}
+ {def happy.is
+  {lambda {:x :a}
+   {if {= :x 1}
+    then true
+    else {if {> {A.in? :x :a} -1}
+    then false
+    else {happy.is {happy.sum :x}
+                   {A.addlast! :x :a}}}}}}
+ {def happy.rec
+  {lambda {:n :a :i}
+   {if {= {A.length :a} :n}
+    then :a
+    else {happy.rec :n
+                    {if {happy.is :i {A.new}}
+                     then {A.addlast! :i :a}
+                     else :a}
+                    {+ :i 1}}}}}
+ {lambda {:n}
+  {happy.rec :n {A.new} 0}}}
+-> happy
+
+{happy 8}
+-> [1,7,10,13,19,23,28,31]