Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-14 Thread Gregg Reynolds
On Sat, Feb 14, 2009 at 9:15 AM, Stuart Cook wrote: > From "Fixing Haskell IO": > > We can summarize the SDIOH (Standard Definition of IO in Haskell) > > as "a value of type IO a is a value, that performs, then delivers > > a value of type a". > > I think you've already made a critical mistake he

Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-14 Thread Stuart Cook
>From "Fixing Haskell IO": > We can summarize the SDIOH (Standard Definition of IO in Haskell) > as "a value of type IO a is a value, that performs, then delivers > a value of type a". I think you've already made a critical mistake here. The quotes you give all describe an IO value as something th

Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-13 Thread roconnor
I also recommend reading (mostly because I wrote it). Feel free to improve upon it. -- Russell O'Connor ``All talk about `theft,''' the general counsel of the American Graphophone Company wro

Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-13 Thread Gregg Reynolds
Hi Daryoush, 2009/2/13 Daryoush Mehrtash > I have been trying to figure out the distinction between value, function > and computation. You raised a few points that I am not sure about. > > > In " "Computation" considered harmful. "Value" not so hot either." you > said: > > I still don't like

Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-13 Thread Roman Cheplyaka
* Daryoush Mehrtash [2009-02-13 11:31:06-0800] > Isn't the lambda expression a representation of something (potentially with > recursion) that yields "a value" and not the value itself? The same terms may refer to different notions. If you think of values as mathematical objects, they are den

Re: [Haskell-cafe] IO semantics and evaluation - summary

2009-02-13 Thread Daryoush Mehrtash
I have been trying to figure out the distinction between value, function and computation. You raised a few points that I am not sure about. In " "Computation" considered harmful. "Value" not so hot either." you said: I still don't like it; a lambda expression is not a computation, it's a for

[Haskell-cafe] IO semantics and evaluation - summary

2009-02-13 Thread Gregg Reynolds
Many thanks to everybody who tried to set me straight on the thread about IO monad and evaluation semantics. I've begun summarizing the info, and I believe I've come up with a much better way of explaining IO; just flip the semantic perspective, and think in terms of interpretations instead of act