<**> and lift2

[mihneagogu]

Hey, how would one use <**> ?
I want the result of two integer parsers to multiply, which is very easy with plain lift2:
lift2(_ * _, intParser1, intParser2). How would one write this using <**> ?
I found this:

val intMul = (x: Int) => (y: Int) => x * y
val mulParser = intParser1 <**> (intParser2.map(intMul) </> identity[Int])

Is there a better way to do this?
Edit: val mulParser = intParser1 <**> (intParser2 <#> intMul) seems to do the trick. Is this the correct way to use <**> ?

[j-mie6]

Yeah, val mulParser = intParser1 <**> intParser2.map(intMul) will do the trick, but you probably want to define:

val intMul = (y: Int) => (x: Int)  => x * y

So that the arguments are reversed, that way it correctly models what you had with the lift2: obviously, for an associative operation like * it doesn't actually matter.

[j-mie6]

By the way, the snippet that you posted is used if you had something like this:

val mulParser = attempt(lift2(_*_, intParser1, intParser2)) <|> intParser1

And you wanted to factor out the leading intParser1 to remove any backtracking.