Deep Lists Assignment

original inspiration for this warmup comes from Extra Practice Problems

Code To Use

• number?
• list?
• foldl
• foldr
• +

Code To Implement

file:	src/main/racket/deep_lists/deep_lists.rkt
functions:	deep-fold deep-flatten deep-sum deep-sum-numbers

Fold

You can elect to build deep-fold as a higher order function which returns a function which will deep fold left or right depending on which list fold function is passed to it.

NOTE: You can also elect to just build deep-foldl and/or deep-foldr directly. If you choose to implement only one of deep-foldl and deep-foldr, be sure to comment out the tests for the unimplemented one.

deep-fold

(define (deep-fold list-fold)
       (error 'not-yet-implemented)) 

deep-fold

(define deep-foldl (deep-fold foldl))

deep-fold

(define deep-foldr (deep-fold foldr))

Clients

deep-flatten

Utilize a version of #deep-fold (and perhaps a list reverse depending on which fold direction you choose) to produce a single flattened list version of the deep list.

For example:

(deep-flatten (list 1 2 (list 3 "fred" 4 5) 6 (list 7 8 (list 9 "george" 10) 11 12)))

should evaluate to

'(1 2 3 "fred" 4 5 6 7 8 9 "george" 10 11 12)

deep-sum

Sums the numbers in a deep list of numbers and lists.

For example:

(deep-sum (list 1 2 (list 3 4 5) 6 (list 7 8 (list 9 10) 11 12)))

should evaluate to 78.

deep-sum-numbers

Like deep-sum only it ignores values which are neither lists nor numbers.

For example:

(deep-sum-numbers (list 1 2 (list 3 "fred" 4 5) 6 (list 7 8 (list 9 "george" 10) 11 12)))

should evaluate to 78.

Test

file:	deep_lists_test.rkt	Test
source folder:	src/test/racket/deep_lists

note: ensure that you have removed all printing to receive credit for any assignment.