Initial data commit

Task/Entropy/Lambdatalk/entropy.lambdatalk

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+{def entropy
+
+ {def entropy.count
+  {lambda {:s :c :i}
+   {let { {:c {/ {A.get :i :c} {A.length :s}}}
+        } {* :c {log2 :c}}}}}
+
+ {def entropy.sum
+  {lambda {:s :c}
+   {- {+ {S.map {entropy.count :s :c}
+                {S.serie 0 {- {A.length :c} 1}}}}}}}
+
+ {lambda {:s}
+         {entropy.sum {A.split :s} {cdr {W.frequency :s}}}}}
+-> entropy
+
+The W.frequency function is explained in rosettacode.org/wiki/Letter_frequency#Lambdatalk
+
+{def txt 1223334444}
+-> txt
+{def F {W.frequency {txt}}}
+-> F
+characters:  {car {F}} -> [1,2,3,4]
+frequencies: {cdr {F}} -> [1,2,3,4]
+{entropy {txt}}
+-> 1.8464393446710154
+
+{entropy 0}
+-> 0
+{entropy 00000000000000}
+-> 0
+{entropy 11111111111111}
+-> 0
+{entropy 01}
+-> 1
+{entropy Lambdatalk}
+-> 2.8464393446710154
+{entropy entropy}
+-> 2.807354922057604
+{entropy abcdefgh}
+-> 3
+{entropy Rosetta Code}
+-> 3.084962500721156
+{entropy Longtemps je me suis couché de bonne heure}
+-> 3.8608288771249444
+{entropy abcdefghijklmnopqrstuvwxyz}
+-> 4.70043971814109
+{entropy abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz}
+-> 4.70043971814109