On Feb 18, 2007, at 21:44 , Michael Vanier wrote:
I think what you're asking here is why you need the parens around (x:y) in the second case. Function application doesn't use parentheses
Function application never applies to pattern matching.
The usual answer to this is "category theory" which is an extremely abstract branch of mathematics. But you
Actually, no; my understanding is that category theory as applied to Haskell is a retcon introduced when the notion of monads was imported from category theory, and the original theoretical foundation of Haskell came from a different branch of mathematics. Lambda calculus is pretty fundamental to Haskell or any functional programming language, as is type theory (although that you really don't have to understand in detail unless you're hacking the type system; most of us leave that to Oleg :) and the Curry-Howard isomorphism (simply stated: computer programs can be converted into mathematical proofs, and vice versa; this is most clearly demonstrated when the programs are described in terms of the lambda calculus, which is where the original formulation of Curry-Howard came from). -- brandon s. allbery [linux,solaris,freebsd,perl] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH