Re: [Haskell-cafe] Bifold: a simultaneous foldr and foldl

2010-11-30 Thread Noah Easterly
On Tue, Nov 30, 2010 at 9:37 AM, Larry Evans cppljev...@suddenlink.netwrote: suggested to me that bifold might be similar to the function, Q, of section 12.5 equation 1) on p. 15 of: http://www.thocp.net/biographies/papers/backus_turingaward_lecture.pdf Now Q takes just 1 argument, a

Re: [Haskell-cafe] Is there a tutorial interpreter to teach haskell?

2010-11-30 Thread Noah Easterly
On Tue, Nov 30, 2010 at 12:08 PM, Larry Evans cppljev...@suddenlink.netwrote: so now I must manually figure out what the a and b in the ap declaration correspond to in the return(:) type: m( a - b ) __ _ _

[Haskell-cafe] Bifold: a simultaneous foldr and foldl

2010-11-29 Thread Noah Easterly
Somebody suggested I post this here if I wanted feedback. So I was thinking about the ReverseState monad I saw mentioned on r/haskell a couple days ago, and playing around with the concept of information flowing two directions when I came up with this function: bifold :: (l - a - r - (r,l)) -