Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Hey Colin, Thanks for the praise. I concentrated a lot on laziness because I think it’s really critical to understanding how Nix works and is probably unfamiliar to everyone outside Haskell land. You might be right about the "white lies” approach. It’s a tricky balance to get right — at one end an unfriendly formal specification; at the other, reader mistrust. :) I’ll try to tone it down. Thanks very much, James On 8 Oct 2014, at 17:50, Colin Putney wrote: > > > On Wed, Oct 8, 2014 at 5:00 AM, James Harrison Fisher > wrote: > Thanks Ellis! If there’s anything you didn’t enjoy, I’d love to know, since > I’ll be writing more of these and I want to establish a style that people > like. :-) > > Awesome article. I especially liked the gory detail on how expression trees > are evaluated. I've been writing nix expressions for a few months and already > knew most of the material you covered, but that section really made it clear > how and why lazy evaluation works the way it does. > > The only thing I didn't enjoy was the "I lied" motif. Especially after the > lazy-lists thing, it made me wonder if I could believe what I was a reading. > The general technique of over-simplifying and then introducing layers of > nuance is good, but I think you over-did it. > > I'm really looking forward to the next article! > > -Colin ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Hey Wout, I’m glad :) And you’ve taught me, too: I’ll correct my statement about the division operator and credit you. And yeah, good catch on the TODO! Thanks! James On 8 Oct 2014, at 17:50, Wout Mertens wrote: > Hi James, > > great reading, I learned a few things! (like that let is a recursive > definition, doh :) ) > > Nix does support the / operator, but it needs spaces or it will be recognized > as a path: > $ nix-instantiate --eval --expr '4/3' > /Users/wmertens/4/3 > $ nix-instantiate --eval --expr '6 / 3' > 2 > > https://github.com/NixOS/nix/blob/b6809608cc467925db44b1eb435095c37e433255/src/libexpr/parser.y#L347 > > Wout. > > PS: (You know that the default-values example is still marked TODO, right?) > > > > On Wed, Oct 8, 2014 at 11:31 AM, Ellis Whitehead > wrote: > Hi James. For what it's worth: I haven't finished it yet, but I've > enjoyed the reading so far. > > On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher > wrote: > > Hi all, > > > > I’ve written up what turned out to be a quite extensive post on the Nix > > expression language: > > > > https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 > > > > I was hoping that someone with more knowledge than me could read it and > > comment on inaccuracies. I’m sure there will be some, since I’m learning > > while writing. > > > > Any and all comments appreciated! > > > > Best, > > > > James > > ___ > > nix-dev mailing list > > nix-dev@lists.science.uu.nl > > http://lists.science.uu.nl/mailman/listinfo/nix-dev > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev > > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Hi James, great reading, I learned a few things! (like that let is a recursive definition, doh :) ) Nix does support the / operator, but it needs spaces or it will be recognized as a path: $ nix-instantiate --eval --expr '4/3' /Users/wmertens/4/3 $ nix-instantiate --eval --expr '6 / 3' 2 https://github.com/NixOS/nix/blob/b6809608cc467925db44b1eb435095c37e433255/src/libexpr/parser.y#L347 Wout. PS: (You know that the default-values example is still marked TODO, right?) On Wed, Oct 8, 2014 at 11:31 AM, Ellis Whitehead wrote: > Hi James. For what it's worth: I haven't finished it yet, but I've > enjoyed the reading so far. > > On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher > wrote: > > Hi all, > > > > I’ve written up what turned out to be a quite extensive post on the Nix > expression language: > > > > https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 > > > > I was hoping that someone with more knowledge than me could read it and > comment on inaccuracies. I’m sure there will be some, since I’m learning > while writing. > > > > Any and all comments appreciated! > > > > Best, > > > > James > > ___ > > nix-dev mailing list > > nix-dev@lists.science.uu.nl > > http://lists.science.uu.nl/mailman/listinfo/nix-dev > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev > ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
On Wed, Oct 8, 2014 at 5:00 AM, James Harrison Fisher < jameshfis...@gmail.com> wrote: > Thanks Ellis! If there’s anything you didn’t enjoy, I’d love to know, > since I’ll be writing more of these and I want to establish a style that > people like. :-) Awesome article. I especially liked the gory detail on how expression trees are evaluated. I've been writing nix expressions for a few months and already knew most of the material you covered, but that section really made it clear how and why lazy evaluation works the way it does. The only thing I didn't enjoy was the "I lied" motif. Especially after the lazy-lists thing, it made me wonder if I could believe what I was a reading. The general technique of over-simplifying and then introducing layers of nuance is good, but I think you over-did it. I'm really looking forward to the next article! -Colin ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Thanks Ellis! If there’s anything you didn’t enjoy, I’d love to know, since I’ll be writing more of these and I want to establish a style that people like. :-) On 8 Oct 2014, at 10:31, Ellis Whitehead wrote: > Hi James. For what it's worth: I haven't finished it yet, but I've > enjoyed the reading so far. > > On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher > wrote: >> Hi all, >> >> I’ve written up what turned out to be a quite extensive post on the Nix >> expression language: >> >>https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 >> >> I was hoping that someone with more knowledge than me could read it and >> comment on inaccuracies. I’m sure there will be some, since I’m learning >> while writing. >> >> Any and all comments appreciated! >> >> Best, >> >> James >> ___ >> nix-dev mailing list >> nix-dev@lists.science.uu.nl >> http://lists.science.uu.nl/mailman/listinfo/nix-dev > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Hi James. For what it's worth: I haven't finished it yet, but I've enjoyed the reading so far. On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher wrote: > Hi all, > > I’ve written up what turned out to be a quite extensive post on the Nix > expression language: > > https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 > > I was hoping that someone with more knowledge than me could read it and > comment on inaccuracies. I’m sure there will be some, since I’m learning > while writing. > > Any and all comments appreciated! > > Best, > > James > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Thanks for looking Luca! And a good point; Debug.trace is a better analogy. On 7 Oct 2014, at 23:33, Luca Bruno wrote: > Length and nice, thanks. Only had a quick look. Note that haskell has > Debug.trace. > > On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher > wrote: > Hi all, > > I’ve written up what turned out to be a quite extensive post on the Nix > expression language: > > https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 > > I was hoping that someone with more knowledge than me could read it and > comment on inaccuracies. I’m sure there will be some, since I’m learning > while writing. > > Any and all comments appreciated! > > Best, > > James > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev > > > > -- > www.debian.org - The Universal Operating System ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
Re: [Nix-dev] Anyone care to review my post on the Nix expression language?
Length and nice, thanks. Only had a quick look. Note that haskell has Debug.trace. On Wed, Oct 8, 2014 at 12:21 AM, James Harrison Fisher < jameshfis...@gmail.com> wrote: > Hi all, > > I’ve written up what turned out to be a quite extensive post on the Nix > expression language: > > https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 > > I was hoping that someone with more knowledge than me could read it and > comment on inaccuracies. I’m sure there will be some, since I’m learning > while writing. > > Any and all comments appreciated! > > Best, > > James > ___ > nix-dev mailing list > nix-dev@lists.science.uu.nl > http://lists.science.uu.nl/mailman/listinfo/nix-dev > -- www.debian.org - The Universal Operating System ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
[Nix-dev] Anyone care to review my post on the Nix expression language?
Hi all, I’ve written up what turned out to be a quite extensive post on the Nix expression language: https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55 I was hoping that someone with more knowledge than me could read it and comment on inaccuracies. I’m sure there will be some, since I’m learning while writing. Any and all comments appreciated! Best, James ___ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
