diff options
Diffstat (limited to 'haskell.html.markdown')
| -rw-r--r-- | haskell.html.markdown | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/haskell.html.markdown b/haskell.html.markdown index 6a64442f..936744a0 100644 --- a/haskell.html.markdown +++ b/haskell.html.markdown @@ -81,7 +81,7 @@ not False -- True [5,4..1] -- [5, 4, 3, 2, 1] -- indexing into a list -[0..] !! 5 -- 5 +[1..10] !! 3 -- 4 -- You can also have infinite lists in Haskell! [1..] -- a list of all the natural numbers @@ -195,11 +195,11 @@ foo 5 -- 15 -- function composition -- the (.) function chains functions together. -- For example, here foo is a function that takes a value. It adds 10 to it, --- multiplies the result of that by 5, and then returns the final value. -foo = (*5) . (+10) +-- multiplies the result of that by 4, and then returns the final value. +foo = (*4) . (+10) --- (5 + 10) * 5 = 75 -foo 5 -- 75 +-- (5 + 10) * 4 = 60 +foo 5 -- 60 -- fixing precedence -- Haskell has another operator called `$`. This operator applies a function @@ -209,14 +209,15 @@ foo 5 -- 75 -- the expression on its right is applied as the parameter to the function on its left. -- before -(even (fib 7)) -- false - --- after -even . fib $ 7 -- false +even (fib 7) -- false -- equivalently even $ fib 7 -- false +-- composing functions +even . fib $ 7 -- false + + ---------------------------------------------------- -- 5. Type signatures ---------------------------------------------------- |