Has anybody heard if they've finalized a spec yet, or at least come close? I've thought about getting into Rust from time to time, but the lack of a finalized spec and/or stable reference implementation has always scared me off.
We're getting close. Rust 0.4 (hopefully to be released next week, assuming no more schedule slips) will be quite close to final syntax-wise. Although not all the features will be implemented, your code will be mostly backwards-compatible.
If you'd like to try out the language, I recommend working off git master rather than 0.3; the language has been dramatically simplified in Rust 0.4.
There is no finalized spec (and the spec has actually fallen quite far behind for the moment), nor do I expect anything about Rust to be called 'final' for a while yet.
The upcoming 0.4 release (any day now) makes a big push to get a lot of the syntax pieces in place, but still has many rough edges. Beyond that the standard library is still an incomplete and inconsistent stew of different styles.
Rust is still firmly alpha software, but should stabilize significantly in the next year.
Rust feels more like Perl 6 (always on the horizon) or Ada (the do everything language), while Go already is already specified, being improved, and out in production.
Oh, come on. Rust started as an open-source project in 2010 (with the release of the preliminary design and OCaml compiler that Graydon had written as a hobby project). At that time, work started on the self-hosting compiler, leading to its initial 0.1 release eight months ago, and proceeding with releases every few months and steady progress toward the remaining goals on the 1.0 roadmap [1]. Just because Go was developed earlier doesn't mean that Rust isn't getting done. And it's not noticeably more complex than it was in the initial design; in some ways it's simpler.
(By contrast, Perl 6 has been in development for over a decade, with a half-dozen implementations in various stages of completion.)
I've attended a few Go meetups here in SF already, and I haven't even seen any Rust meetups on the radar.
At these Go meetups, companies are presenting what they're using Go for in production already, with great success. Go is not difficult to program in, Go is functional, Go is performant, Go is developer friendly.
That is not to say that Go doesn't have warts, it does (32-bit garbage collecting anyone? or the slow regular expression engine?), but people from Ruby, people from Python, and people from JavaScript are gravitating toward Go and _enjoying_ it.
Go also has excellent stewardship in the form of Pike et al.
In my mind, at least, the gap between Rust and Go is pretty big at this point. This is why Rust feels like vaporware (especially compared to Go).
People like to compare Go and Rust, and I think the comparison is pretty natural. The difference is that Go already has "boots on the ground."
If Rust releases something awesome in the next few months, the gap between Go and Rust could rapidly close (depending on developer adoption). But, in my mind, the longer Rust takes to iron out the quirks of it's syntax (not implementation, syntax!), the wider that gap will get.
When Go was announced it had a spec, a significantly larger standard library than Rust, two compilers (and a parser in the standard library), and much, much better documentation. While the language had changed until the Go 1 release from a few months ago, it had changed less in two years than Rust changed in a few months. Go also introduced a tool that would automatically rewrite your old code to adapt to the new language changes.
All that means is that Go was announced much later in the development process than Rust was. If Rust had been developed like Go, it wouldn't have been made public yet. But that's not the way Mozilla does things.
In nine months, Rust has gone from version 0.1 (its first public release) to version 0.4 (expected next week). Much of the work in that time has involved removing (!!!) features from the language and polishing what's left. Version 1.0 is anticipated in the first half of next year.
If you really feel the need to compare with Go, measure the time from Go's first public release (2009) to its first production release (2012).
I don't know if this is a fair criticism. Rust has not been stuck in eternal development for many years like Perl 6. Rust is less mature than Go just because it started (in earnest) later and it's a little more ambitious. Go was immature not that long ago.
> I don't think it's like that. I think they're just developing it through usage.
What's shipping with it?
I have a bit of the same impression that the other poster has, that it's always in development without something stable. I hope that gets dispelled sooner or later, because, for better or worse, fuzzy marketing type things like that matter.
Your impression is completely accurate; the language is in development and is not ready to use yet. It shouldn't be used in any shipping products. There's nothing to "dispel" here until the 1.0 syntax is is finalized; fortunately that should happen in months rather than years.
From a pure marketing perspective, sure, maybe it would be better to finish more of the design and implementation before talking about it publicly. But Mozilla's pretty committed to working in the open, and that has its own benefits. For example, significant parts of the Rust implementation were created by contributors who were not paid Mozilla staff, including a Google employee (in her spare time).
(Disclosure: I'm a Mozilla employee but not part of the Rust team; I've contributed a little bit to the Rust compiler in my free time.)
