Curry in Swift and Javascript

Source: bwallpapers.com

You may encounter curry in everyday code without knowing it. Here is a bit of my reflections on curry and how to apply it in Javascript and Swift.

Taking one parameter in Haskell

In Haskell, all function officially takes only 1 parameter. Function with many parameters are just curried, which means they will be partially applied. Calling sum 1 just returns a function with 1 parameter, then 2is passed into this function. The following 2 function calls are the same.

ghci> sum 1 2
3 
ghci> (max 1) 2
3

I tend to think of curried function or partially applied function as something that carry dependencies at each application step. Each curried function can be assigned to variable or pass around, or as returned value.

Curry in Swift for predicate

When I was trying to make my own Signal library, I have

and Event