On 02/07/2012 11:59 AM, Brian Anderson wrote:
On 07/01/2012 03:47 PM, Jesse Jones wrote:
I'm confused about how I can structure libraries. Let's say I have a
whizbang library. It's complex enough that I want whiz and bang
submodules, but that's just an implementation detail: I'd like clients
of the libraries to use the public API with just an `import
whizbang;`. I had thought something like the following would work:
whizbang.rs
import whiz::*;
import bang::*;
export whiz1, whiz2;
export bang1;
whiz.rs:
fn whiz1() {}
fn whiz2() {}
bang.rs:
fn bang1() {}
And it does work…but only within the whizbang project. whiz.rs, for
example, can use bang1 without even doing an import. But external
libraries have to do whizbang::whiz::whiz1.
I would expect this to work as written. core.rs does similar things to
expose option::some, none, etc. Perhaps it's because of a resolve bug.
core doesn't use `import::*` for example, so maybe reexporting an import
star is funky.
I can see two possibilities:
#1: The bug report is ambiguous. It's not clear whether the reporter
wants to be able, in external libraries, to write:
import whizbang; // import from where?
bang1(); // import didn't mention this
or something else. That example, as written, won't work for 2
reasons: 'import' and 'use' are different directives, and anyway
import only imports the name 'whizbang', not any of the sub-names.
I _would_ expect the following example to work:
use whizbang; // link in the library
whizbang::bang1(); // access through the linked name
#2: There might be a bug in resolve concerning the import/export
interaction. This is ... if true, one of a long set of bugs
that we have so many of on resolve that patrick is presently
rewriting that module of the compiler from scratch (about to
merge probably this week) to approach the resolve algorithm
in an entirely different fashion.
If it's just #1, try the other example and see how it fares. If it's #2,
I'd suggest waiting until the resolve rewrite lands and then trying
again to see if the bug goes away. There were a ton of weird corner
cases surrounding globbed imports in the old code. We're pretty
convinced it wasn't even well-defined (global order-sensitivity,
infinite loop possibilities, all sorts of awfulness).
-Graydon
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