module HW7 where

import Hugs.Prelude

-- WEEK 7

{-######################################

QUESTION 10.2

######################################-}

-- Test Functions

f::Int->Bool

f n

| n==0=True

| otherwise=False

{-

"(id.f) (f.id) id f = f "

id is a polymorphic function that returns its argument,

so doing the 3 cases above just execute f

-}

{-######################################

QUESTION 10.3

######################################-}

myinc::Int->Int

myinc x=x+1

composeList::[(a->a)]->(a->a)

composeList []=id

composeList (x:xs)=x. composeList xs

{-

upon testing "composeList" with my function "myinc"

I obtain the following result:

composeList [(myinc),(myinc),(myinc)] 5 ==>8

the "myinc" function is applied to 5 3 times which

has the same result as doing myinc(myinc(myinc 5))=>8

when i use composeList [] 5 i get back 5 because it is the

empty list case and the function "id" is applied to 5

-}

{-######################################

QUESTION 10.7

######################################-}

flip::(a->b->c)->(b ->a->c)

flip func =(\x y->func y x)

{-######################################

QUESTION 10.8

######################################-}

notwhite::Char->Bool

notwhite = \ch->not(elem ch " \t\n")

{-######################################

QUESTION 10.9

######################################-}

total::(Int->Int)->(Int->Int)

total func= \n-> sum(map func [0..n])

{-######################################

QUESTION 10.10

a very aproximative derivative at x

slope=f(x+dx)-f(x)/(dx)

calculate the slope at point x for f

######################################-}

slope::(Float->Float)->(Float->Float)

slope func= \n->( (func (n+0.2))- (func n) ) /(0.2)

{-######################################-}

{-######################################-}