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-rw-r--r--haskell.html.markdown21
1 files changed, 18 insertions, 3 deletions
diff --git a/haskell.html.markdown b/haskell.html.markdown
index 936744a0..940cf4c7 100644
--- a/haskell.html.markdown
+++ b/haskell.html.markdown
@@ -193,7 +193,7 @@ foo = (+10)
foo 5 -- 15
-- function composition
--- the (.) function chains functions together.
+-- the operator `.` 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 4, and then returns the final value.
foo = (*4) . (+10)
@@ -401,11 +401,26 @@ main'' = do
let foo = 5
--- You can see the type of any value with `:t`:
+-- You can see the type of any value or expression with `:t`:
->:t foo
+> :t foo
foo :: Integer
+-- Operators, such as `+`, `:` and `$`, are functions.
+-- Their type can be inspected by putting the operator in parentheses:
+
+> :t (:)
+(:) :: a -> [a] -> [a]
+
+-- You can get additional information on any `name` using `:i`:
+
+> :i (+)
+class Num a where
+ (+) :: a -> a -> a
+ ...
+ -- Defined in ‘GHC.Num’
+infixl 6 +
+
-- You can also run any action of type `IO ()`
> sayHello