Initial data commit

Task/Huffman-coding/SETL/huffman-coding.setl

@@ -0,0 +1,38 @@
+var forest := {}, encTab := {};
+
+plaintext := 'this is an example for huffman encoding';
+
+ft := {};
+(for c in plaintext)
+  ft(c) +:= 1;
+end;
+
+forest := {[f, c]: [c, f] in ft};
+(while 1 < #forest)
+  [f1, n1] := getLFN();
+  [f2, n2] := getLFN();
+  forest with:= [f1+f2, [n1,n2]];
+end;
+addToTable('', arb range forest);
+
+(for e = encTab(c))
+  print(c, ft(c), e);
+end;
+
+print(+/ [encTab(c): c in plaintext]);
+
+proc addToTable(prefix, node);
+  if is_tuple node then
+    addToTable(prefix + '0', node(1));
+    addToTable(prefix + '1', node(2));
+  else
+    encTab(node) := prefix;
+  end;
+end proc;
+
+proc getLFN();
+  f := min/ domain forest;
+  n := arb forest{f};
+  forest less:= [f, n];
+  return [f, n];
+end proc;