Monads

[Hannah Schroeter]

Hello!

On Thu, May 17, 2001 at 11:57:45AM +0200, Rijk-Jan van Haaften wrote:

> >So what you are saying is that I actually don't need
> >Monads to perform the tasks Monads supports ?

> Indeed. However, not using the Monadic do syntax results in
> hardly-readible code.

I don't really think so. The operator precedences for >> and >>= are
quite okay, especially combined to the precedence of lambda binding.

How is

main =
	getLine					>>= \line ->
	let number = read line in
	let result = number + 42 in
	print result

less readable than

main = do
	line <- getLine
	let number = read line
	let result = number + 42
	print result
?

Or

main =
	putStr "Hello! What's your name?"	>>
	getLine					>>= \name ->
	putStrLn ("Hello, " ++ name ++ "!")

compared to

main = do
	putStr "Hello! What's your name?"
	name <- getLine
	putStrLn ("Hello, " ++ name ++ "!")

> [...]

Yes, I use do syntax where appropriate (e.g. also for usual parser
monads), however, the operator syntax can be written quite readably
too.

Kind regards,

Hannah.