use_group_as RFC

text/0000-use-group-as.md

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+- Feature Name: use_group_as
+- Start Date: 2015-02-15
+- RFC PR: (leave this empty)
+- Rust Issue: (leave this empty)
+
+# Summary
+
+Allow renaming imports when importing a group of symbols from a module.
+
+```rust
+use std::io::{
+    Error as IoError,
+    Result as IoResult,
+    Read,
+    Write
+}
+```
+
+# Motivation
+
+THe current design requires the above example to be written like this:
+
+```rust
+use std::io::Error as IoError;
+use std::io::Result as IoResult;
+use std::io::{Read, Write};
+```
+
+It's unfortunate to duplicate `use std::io::` on the 3 lines, and the proposed
+example feels logical, and something you reach for in this instance, without
+knowing for sure if it worked.
+
+# Detailed design
+
+The current grammar for use statements is something like:
+
+```
+  use_decl : "pub" ? "use" [ path "as" ident
+                            | path_glob ] ;
+
+  path_glob : ident [ "::" [ path_glob
+                            | '*' ] ] ?
+            | '{' path_item [ ',' path_item ] * '}' ;
+
+  path_item : ident | "self" ;
+```
+
+This RFC proposes changing the grammar to something like:
+
+```
+  use_decl : "pub" ? "use" [ path [ "as" ident ] ?
+                            | path_glob ] ;
+
+  path_glob : ident [ "::" [ path_glob
+                            | '*' ] ] ?
+            | '{' path_item [ ',' path_item ] * '}' ;
+
+  path_item : ident [ "as" ident] ?
+            | "self" [ "as" ident];
+```
+
+The `"as" ident` part is optional in each location, and if omitted, it is expanded
+to alias to the same name, e.g. `use foo::{bar}` expands to `use foo::{bar as bar}`.
+
+This includes being able to rename `self`, such as `use std::io::{self
+as stdio, Result as IoResult};`.
+
+# Drawbacks
+
+# Alternatives
+
+# Unresolved Questions