Re: [Haskell-beginners] pattern matching on a common element

On Fri, 25 Nov 2016 18:18:21 +0100 Daniel Trstenjak <daniel.trstenjak@gmail.com> wrote:

Hi Brian,

...

interestingly in my journeys through the intertubes I have not found a single mention of using the "()" syntax in place of the "{fieldname=value, ...}" syntax as the generator.

The '()' isn't part of the 'data constructor' (the usual term for A1/A2/A3), but sometimes needed to help the compiler to make an unambiguous parsing of the expression.

These are all valid expressions:

i $ A1 "foo" 3.2 -- '$' is often used to get rid of parentheses

let a1 = A1 "foo" 3.2 in i a1

oh, i see. everything's a function. thanks! Brian