__   __ __  __  ____   ___      _______________________________________________
||   || ||  || ||  || ||__      Hugs 98: Based on the Haskell 98 standard
||___|| ||__|| ||__||  __||     Copyright (c) 1994-2005
||---||         ___||           World Wide Web: http://haskell.org/hugs
||   ||                         Bugs: http://hackage.haskell.org/trac/hugs
||   || Version: Sep 2006       _______________________________________________

Haskell 98 mode: Restart with command line option -98 to enable extensions

Type :? for help
Main> :edit
Main> :r
Main> strToFn "plus"
ERROR - Cannot find "show" function for:
*** Expression : strToFn "plus"
*** Of type    : Integer -> Integer -> Integer

Main> (strToFn "plus") 5 7
12
Main> (buildStringEnder ", eh?") "hello"
"hello, eh?"
Main> \x -> x * 5
ERROR - Cannot find "show" function for:
*** Expression : \x -> x * 5
*** Of type    : Integer -> Integer

Main> :r
Main> safeSqrt 100
10.0
Main> :type safeSqrt
safeSqrt :: Floating a => a -> a
Main> ( (\x->x+1) . (\y->y*2) ) 100
201
Main> sqrt . abs 10
ERROR - Cannot infer instance
*** Instance   : Num (b -> a)
*** Expression : sqrt . abs 10

Main> applyToAll (+1) [2,3,4,5,6]
[3,4,5,6,7]
Main> applyToAll (\n->n*n) [2,3,4,5,6]
[4,9,16,25,36]
Main> map (+1) [1..10]
[2,3,4,5,6,7,8,9,10,11]
Main> :r
Main> keep even [0..10]
ERROR - Cannot find "show" function for:
*** Expression : keep even (enumFromTo 0 10)
*** Of type    : [Integer -> Bool]

Main> keep (even) [0..10]
ERROR - Cannot find "show" function for:
*** Expression : keep even (enumFromTo 0 10)
*** Of type    : [Integer -> Bool]

Main> :r
Main> keep (even) [0..10]
[0,2,4,6,8,10]
Main> keep (\l->length l <= 2) [[1,2,3], [4,5], [8], [3,4,5,6]]
[[4,5],[8]]
Main> :type keep
keep :: (a -> Bool) -> [a] -> [a]
Main> filter (\l->length l <= 2) [[1,2,3], [4,5], [8], [3,4,5,6]]
[[4,5],[8]]
Main> :r
Main> :r
Main> largest [1,2,3]
ERROR - Cannot infer instance
*** Instance   : Num [a]
*** Expression : largest [1,2,3]

Main> :r
Main> :type reduce
reduce :: (a -> a -> a) -> [a] -> a
Main> :type foldr1
foldr1 :: (a -> a -> a) -> [a] -> a
Main> foldr1 (\l1 l2->if (length l1) > (length l2) then l1 else l2) [[1,2],[3,4]]
[3,4]
Main> :type foldr
foldr :: (a -> b -> b) -> b -> [a] -> b
Main> foldr (\n m->n) (error "hello") [2,3,4]
2
Main> foldr (\n m->n) (error "hello") []

Program error: hello

Main> foldr (\n ->n m) (error "hello") [2,3,4]
ERROR - Undefined variable "m"
Main> foldr (\n m-> m) (error "hello") [2,3,4]

Program error: hello

Main>