Guide: match #15434
Guide: match #15434
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| Finally, a comment about Windows. Rust considers Windows to be a first-class | ||
| platform upon release, but if we're honest, the Windows experience isn't as | ||
| integrated as the Linux/OS X experience is. We're working on it! If anything |
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Whoah whaoh. this whole section shouldn't be. My filesystem has been screwy lately....
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This is now right. Whoah.
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I think this reasonable fine, although it doesn't mention (there's no particular need to mention them now if you have a plan):
Also, some things that could be mentioned at some point, but haven't got enough background:
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Yeah, the last two really needs pointers. This isn't intended to be super exhaustive, so I left off name bindings on purpose. I haven't decided when to put in nested patterns, but it seems like a good plan for when I talk about |
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| `match` takes an expression, and then branches based on its value. Each 'arm' of | ||
| the branch is of the form `val => expression`. When the value matches, that arm's | ||
| expression will be evaluated. It's called `match` becuase of the term 'pattern |
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@huonw on the three:
Can you think of a decent example of these two? I haven't used them enough. I do think they should be covered here.
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@steveklabnik here's on example of a place I've used a nested pattern: match r.read(buf) {
Ok(bytes) => { /* process buf */ }
Err(IoError { kind: EndOfFile, .. }) => { /* bail out */ }
Err(err) => { /* handle error */ }
} |
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@sfackler hmmm, interesting. That uses too many details I haven't talked about already, maybe that means it's a good candidate to put later in the guide. |
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After thinking about it, this is good to go for now. I'm actually going to have to introduce @brson r? |
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| So what's the big advantage here? Well, there are a few. First of all, `match` | ||
| does 'exhaustiveness checking.' Do you see that last arm, the one with the | ||
| underscore (`_`)? If we remove that arm, Rust will give us an error: |
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It would be nice to write the failing code here, so the readers can try it out and experience the error for themselves.
…=lnicola minor : Deunwrap generate_derive rust-lang#15398 subtask 1. Since the editing closure has arms, I did something *experimental* ( in this case just a clever term for bad code ) to bypass creating an `Option` but I am ready to change this.
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