ghci

tell what type x is

:t x

enable multiline input

:set +m

sample function definition (put all on one line with ; if not in multiline mode)

let fac 0 = 1
    fac n = b * fac(n - 1)

redefine command prompt note, can put these in a ~/.ghci or ~/.ghc/ghci.conf

:set prompt "λ "

Language

Can use $ and . to get rid of most other punctuation. Details? Binding?

Nim triples with list comprehensions:

import Data.Bits
let range = [1..8]
[ (a,b,c) | a <- range, b <- range, c <- range, a < b, b < c, xor a b == c ]

Infinite data structures

let doubles = zipWith (+) h h  where h = [1..100]
fibs = 0 : zipWith (+) fibs (1 : fibs)

Sketch of how to do primes

let hasNoDivisor n list = null [ d | d <- list, mod n d == 0 ]
let primes = 2 : minimum [ p | p <- [1..], hasNoDivisor p primes ]