I need the following exercise’s completed in the programming language “Haskell”.
Put all the exercise’s into a file called “ps.hs” to run it.
A Makefile is also uploaded, however it is in the form of a “.doc” file, remove it and you should be able to run it.
There is also a Test file uploaded along with it. However to use the Test file you must make it a “.t” file by renaming it and putting it at the end.
#1: Write a function “zeroIsNothing” which
–> converts 0 to Nothing, and any other number to Just that number
–> also write its type signature
zeroIsNothing z
| otherwise = 1
#2: Write a function “nothingIsZero” which
— converts Nothing to 0, and (Just a) to the number a
— also write its type signature
nothingIsZero a = a
#3: Create a typeclass called NumOrString that can contain either an Integer or String object.
— make sure your NumOrString class includes “deriving (Show)” so that
— it may be printed
— write a function makeNum
— which accepts an Integer and produces a NumOrString object that
— encapsulates its value
— also write its type signature
makeNum a = a
#4: Write a function getNum which accepts a NumOrString object
— produces a Maybe object, where
— if the NumOrString object is a number, it should be “Just <that
— number>”
— otherwise, Nothing
— also write its type signature
getNum a = a
#5: Write a function makeString
— which accepts an String and produces a NumOrString object that
— encapsulates its value
— also write its type signature
makeString a = a
#6: Write a function getString which accepts a NumOrString object
— produces a Maybe object, where
— if the NumOrString object is a String, it should be “Just <that
— string>”
— otherwise, Nothing
— also write its type signature
getString a = a
#7: Write a function named “makeNumList” which accepts a numeric argument
— and outputs a list of that many NumOrString objects, counting up
— from 1 to the argument
— e.g. “makeNumList 5” should produce:
— [<NumOrString object with numeric 1>, <NumOrString object with numeric 2>, <NumOrString object with numeric 3>, <NumOrString object with numeric 4>, <NumOrString object with numeric 5>]
— and where
— map getNum <that list> should be [Just 1,Just 2,Just 3,Just 4,Just 5]
— to get the list in the right order, you may need to use Haskell’s append operator, which is ++
— note the type signature of (++) is
— (++) :: [a] -> [a] -> [a]
makeNumList n = [1, 2, 3]
#8: Let’s write bucket in Haskell
— it takes a list of numbers and outputs a list of lists-of-numbers,
— where like numbers are grouped together.
— e.g. bucket [1,1,3,3,3,5,4,4] is
[[1,1],[3,3,3],[5],[4,4]]
— use foldr (fold from the right)
— think about the base case; in this example,
— you’re combining 4 and [] (and you should output [[4]])
— then next you’ll be combining 4 and [[4]]
— and you should output [[4,4]]
— then next you’ll be combining 5 and [[4,4]]
— and you should output [[5],[4,4]]
— define the bucket op fcn first
— name it bucket_op, and write its type signature
bucket_op n l = []
— now write the main bucket (which must use foldr and bucket_op)
bucket l = []
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