I have the following lambda function in haskell:
cup size = \message -> message size
I would like to know what is the equivalent version in JavaScript (for learning purpose), currently I wrote the following version, I would like to if it is correct.
const cup = size => (message => message)(size)
Your JavaScript code corresponds to
cup = \size -> (\message -> message) size
in Haskell. Because \message -> message is the identity function, this is the same as
cup = \size -> size
which is the identity function again:
cup = id
The correct translation would be
const cup = size => message => message(size)
or
function cup(size) { return message => message(size); }
Your haskell lambda takes an argument and returns a lambda which in turn takes a function as argument and applies that function with the argument given to cup.
In javascript, the equivalent would be this:
const cup = size => (message => message(size))
You can rewrite it without the parenthesis:
const cup = size => message => message(size)
messagea method ? Because if yes i do not get the usage of lambda.You could writecup=messageand in jscup=str=>message(str)cupis notmessage;cupis a function that returns a function which applies its argument tocup's argument. One could also writecup size message = message size, which makes it more apparent thatcup = flip ($).