September 2017 Update

Task/Run-length-encoding/Jq/run-length-encoding-1.jq

@@ -0,0 +1,9 @@
+def runs:
+  reduce .[] as $item
+    ( [];
+      if . == [] then [ [ $item, 1] ]
+      else .[length-1] as $last
+      | if $last[0] == $item then .[length-1] = [$item, $last[1] + 1]
+        else . + [[$item, 1]]
+        end
+      end ) ;

Task/Run-length-encoding/Jq/run-length-encoding-2.jq

@@ -0,0 +1,9 @@
+def run_length_encode:
+  explode | runs | reduce .[] as $x (""; . + "\($x[1])\([$x[0]]|implode)");
+
+def run_length_decode:
+  reduce (scan( "[0-9]+[A-Z]" )) as $pair
+    ( "";
+      ($pair[0:-1] | tonumber) as $n
+      | $pair[-1:] as $letter
+      | . + ($n * $letter)) ;

Task/Run-length-encoding/Jq/run-length-encoding-3.jq

@@ -0,0 +1 @@
+"ABBCCC" | run_length_encode | run_length_decode

Task/Run-length-encoding/Jq/run-length-encoding-4.jq

@@ -0,0 +1,2 @@
+$ jq -n -f Run_length_encoding.jq
+"ABBCCC"