Try disallowing keywords as identifiers

[brson]

The distinction between bad words and contextual keywords is difficult to keep track of. Built-in types are no longer keywords, which allows us to create things like mod int. It may be fairly easy now to disallow keywords as identifiers.

[graydon]

I agree, though this is RFC-level to the extent that others probably ought to comment.

[catamorphism]

I agree. Simplify!

[pcwalton]

Agreed.

[bstrie]

Is this done? I note that this program doesn't compile:

fn main() {
    let pure: ~str = ~"asdf";
    io::println(pure);
}

Same if you replace pure with for or fn.

[bblum]

Not done; the program works with with or move as the identifier name.

I'm in favour of this change. Makes syntax hilighting easier.

[metajack]

This appears to be necessary to make the grammar LL(1). See https://mail.mozilla.org/pipermail/rust-dev/2013-April/003780.html

[bstrie]

Regardless of the grammar situation, this is still a good change to make. Let's not bother enabling IF IF THEN THEN ELSE ELSE.

[emberian]

I think this is fixed, but it needs a testcase for every keyword... simple way would be to write a script that sucks in the list of keywords and spits out a file for each of them, generated from a simple template. Needs to do this to ensure that they each don't compile.

[pnkfelix]

Closed by PR #8739