Day 7 of #100DaysOfClojure

Today I wrapped up chapter 1 of Living Clojure. I also solved 3 prolems on 4clojure

• Pack a sequence
• Compress a sequence
• Duplicate a sequence

I had started on compress a sequence yesterday and got frustrated. Today I started workingon duplicating a sequence first and solved it after a number of failed attempts. After realizing that it could be solved by concatenating a sequence of sequences, I stumbled across the partition-by and identity functions. From there the other two fell into place rather easily

Solutions

Here are my solutions; I solved them in reverse order of listing

Pack a sequence

#(partition-by identity %)

Compress a sequence

#(reduce concat (map distinct (partition-by identity %)))

Duplicate a sequence

#(reduce concat (map (fn dbl [x] (list x x)) %))