operators

infix function

> :type (==)
forall (@a :: Type). Eq a => a -> a -> Boolean

• operator

  • the equality operator, = = is a function. So are +, *, -, / and pretty much all operators.

• If a function is comprised only of special characters, it's considered an infix function by default.

we have to surround it in parentheses, if we want to

• examine its type (use :t or :type)
• pass it to another function or
• call it as a prefix function

Operators can be partially applied by surrounding them with parentheses and using _ as one of the operands: https://github.com/purescript/documentation/blob/master/language/Syntax.md#operator-sections

add5 x = 5 + x
add5 x = add 5 x
add5 x = (+) 5 x
add5 x = 5 `add` x
add5   = add 5
add5   = \x -> 5 + x
add5   = (5 + _)
add5 x = 5 `(+)` x  -- Yo Dawg, I herd you like infix, so we put infix in your infix!