Haskell CW II.6

Simplified Design

• Signature
• Purpose (frequently given in the problem)
• Examples
  • Build from simple to complex
  • Roadmap for writing
• Write code.
• Test (check-expect)

Opener

Examples:

lotsOfLetters [4] == "aaaa"
lotsOfLetters [3,1,4] == "aaabcccc"
lotsOfLetters [3,1,4,1,5] == "aaabccccdeeeee"

More than one approach works well!

Today: handle one letter at a time, use a helper.

Multiple simple helpers is good.

Check-Expect

Just make a list of Boolean values that should all be True.

checkLots = [
    lotsOfLetters [4] == "aaaa"
    ,lotsOfLetters [3,1,4] == "aaabcccc"
    ,lotsOfLetters [3,1,4,1,5] == "aaabccccdeeeee"
    ]

main = do putStrLn $ show checkLots