spin words example added

examples/PSB2/annotations/spin_words.ae

@@ -0,0 +1,18 @@
+type List;
+
+def String_len : (i:String) -> Int = native "lambda i: len(i)";
+def String_list_to_String : (l:List) -> String = native "lambda l: ' '.join(l)";
+def map_String_String_List: (function:(a: String) -> String) -> (l: List) -> List = native "lambda f: lambda xs: map(f, xs)";
+def String_split : (i:String) -> (j:String) ->  List = native "lambda i: lambda j: i.split(j)" ;
+def String_reverse : (i:String) -> String = native "lambda i: i[::-1]";
+
+def spin_words (phrase: String) : String {
+    words: List = String_split(phrase)(" ");
+    reversed_words: List = map_String_String_List ((\x -> if (String_len(x) >= 5) then String_reverse(x) else x):(x:String)->String) (words);
+
+    String_list_to_String(reversed_words)
+ }
+
+def main (args:Int) : Unit {
+    print (spin_words("this is another test"))
+}