Last I did a survey, `let mut` was less than half (and more around 30-40%) of the `lets` I found, though it wasn't exhaustive. It's also important to note that Rust is not a language suited for new programmers. Far too many concerns; it tackles hard problems and makes tradeoffs that new programmers don't particularly benefit from, esp. pedagogically.
(I also teach new programmers, at Thinkful) On Wed, Jan 29, 2014 at 10:09 PM, Samuel Williams <space.ship.travel...@gmail.com> wrote: > I agree that it is syntactic salt and that the design is to discourage > mutability. I actually appreciate that point as a programmer. > > w.r.t. this specific issue: I think what concerns me is that it is quite a > high burden for new programmers (I teach COSC1xx courses to new students so > I have some idea about the level of new programmers). For example, you need > to know more detail about what is going on - new programmers would find that > difficult as it is one more concept to overflow their heads. > > Adding "var" as a keyword identically maps to new programmer's expectations > from JavaScript. Writing a program entirely using "var" wouldn't cause any > problems right? But, could be optimised more (potentially) if using "let" > for immutable parts. > > Anyway, I'm not convinced either way, I'm not sure I see the entire picture > yet. But, if I was writing code, I'd certainly get sick of writing "let mut" > over and over again - and looking at existing rust examples, that certainly > seems like the norm.. > > > > > > > On 30 January 2014 15:59, Samuel Williams <space.ship.travel...@gmail.com> > wrote: >> >> I guess the main gain would be less typing of what seems to be a >> reasonably common sequence, and the formalisation of a particular semantic >> pattern which makes it easier to recognise the code when you visually >> scanning it. >> >> >> On 30 January 2014 15:50, Kevin Ballard <ke...@sb.org> wrote: >>> >>> On Jan 29, 2014, at 6:43 PM, Brian Anderson <bander...@mozilla.com> >>> wrote: >>> >>> > On 01/29/2014 06:35 PM, Patrick Walton wrote: >>> >> On 1/29/14 6:34 PM, Samuel Williams wrote: >>> >>> Perhaps this has been considered already, but when I'm reading rust >>> >>> code >>> >>> "let mut" just seems to stick out all over the place. Why not add a >>> >>> "var" keyword that does the same thing? I think there are lots of >>> >>> good >>> >>> and bad reasons to do this or not do it, but I just wanted to propose >>> >>> the idea and see what other people are thinking. >>> >> >>> >> `let` takes a pattern. `mut` is a modifier on variables in a pattern. >>> >> It is reasonable to write `let (x, mut y) = ...`, `let (mut x, y) = ...`, >>> >> `let (mut x, mut y) = ...`, and so forth. >>> >> >>> >> Having a special "var" syntax would defeat this orthogonality. >>> > >>> > `var` could potentially just be special-case sugar for `let mut`. >>> >>> To what end? Users still need to know about `mut` for all the other uses >>> of patterns. This would reserve a new keyword and appear to duplicate >>> functionality for no gain. >>> >>> -Kevin >>> _______________________________________________ >>> Rust-dev mailing list >>> Rust-dev@mozilla.org >>> https://mail.mozilla.org/listinfo/rust-dev >>> >> > > > _______________________________________________ > Rust-dev mailing list > Rust-dev@mozilla.org > https://mail.mozilla.org/listinfo/rust-dev > _______________________________________________ Rust-dev mailing list Rust-dev@mozilla.org https://mail.mozilla.org/listinfo/rust-dev
