RWH CH01 Notes

 

Haskell is lazy evaluation!

 

 

Prelude> :show bindings 

Prelude> let x = 2010
Prelude> :show bindings 
x :: Integer = _
Prelude> x
2010
Prelude> :show bindings 
it :: Integer = 2010
x :: Integer = 2010
Prelude>

 

Exercises Answers:

 

3: The words function counts the number of words in a string. Modify the WC.hs example to count the number of words in a file.

 

 

main = interact wordCount
    where wordCount input = show (length (words input)) ++ "\n"

 

4: Modify the WC.hs example again, to print the number of characters in a file.

 

main = interact wordCount
    where wordCount input = show (length input) ++ "\n"

 

Useful command

:set +t

:unset +t

:m Data.Radio 

it