Calling up a function is as simple as specifying the function name, followed by the parameters. Parenthesis is optional, just like in Ruby.
max 12 (-12)
λ: max 12 (-12) 12
Defining a function is similar to calling it.
doubleMe x = x + x
λ: doubleMe 21 42
Function with an
odd' x = if x `mod` 2 == 0 then True else False
Note: In Haskell, there has to be a mandatory
else block for every
if. That’s basically because
if statement is an expression and must evaluate to some value.
Note 2: There is no
else if statement in Haskell. We use pattern matching or guards for such use cases.
We can call and assign values from function return:
λ: is_odd = odd' 27 λ: is_odd True λ:
If you notice
is_odd also defined exactly like a function is like. A function without parameters is called a
definition in Haskell.