[Haskell-cafe] Trouble with currying and uncurrying...

[Angel de Vicente]

Hi,

I'm reading "The Craft of Functional Programming" and I found something 
I don't understand in page 185.

It says:

"Suppose first that we want to write a curried version of a function g, 
which is itself uncurried and of type (a,b) -> c.

curry g

This funtion expects its arguments as a pair, but its curried version, 
curry g, will take them separately - we therefore have to form them into 
a pair before applying g to them:

curry :: ((a,b) -> c) -> (a -> b -> c)
curry g x y = g (x,y)

curry multiplyUC will be exactly the same function as multiply."

OK, I have tried it and it works, but I don't understand the syntax for 
curry. Until now I have encountered only functions that take the same 
number of arguments as the function definition or less (partial 
application), but this syntax looks a bit new to me. curry is supposed 
to have as its argument one function of type (a,b) -> c and produce 
another function, but then the second line gives three arguments to 
curry, the function itself and the variables x and y.

What I'm missing here?

Thanks a lot,
Ángel de Vicente
-- 
http://www.iac.es/galeria/angelv/

High Performance Computing Support PostDoc
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