[Haskell-beginners] infix and bind pseudonym

[Daniel Fischer]

Am Mittwoch, 4. März 2009 13:59 schrieb Magnus Therning:
> Yes, there are certain function names that allow infix usage without
> the back-ticks, the name 'chain' doesn't.  What those function names
> are?  Roughly you can say that functions that they are functions that
> look like binary operations, like + - ++ >>> etc.  I'm not sure I read
> the pangauage spec correctly, but it looks like operators are made up
> of the following characters !@#$%^&*+-./\|<=>?~ (IIRC ':' has a
> special meaning in that it's allowed in "constructors", cf 1:2:[]).

':' is the symbol-equivalent of an upper case letter, so it's special only if 
it's the first symbol of an operator name, then the operator is a 
constructor. It can appear in any place but the first in ordinary operators.
For example:
	(:) :: a -> [a] -> [a]	-- first symbol is ':' => constructor
	(:+) :: (RealFloat a) => a -> a -> Complex a	-- constructor
	(/:/) :: a -> b -> b 	-- ':' not first symbol => ordinary operator

>
> /M