auto merge of #8288 : Kimundi/rust/opteitres4, r=brson

This is an alternative version to https://github.com/mozilla/rust/pull/8268, where instead of transitioning to `get()` completely, I transitioned to `unwrap()` completely.

My reasoning for also opening this PR is that having two different functions with identical behavior on a common datatype is bad for consistency and confusing for users, and should be solved as soon as possible. The fact that apparently half the code uses `get()`, and the other half `unwrap()` only makes it worse.

If the final naming decision ends up different, there needs to be a big renaming anyway, but until then it should at least be consistent.

---

- Made naming schemes consistent between Option, Result and Either
- Lifted the quality of the either and result module to that of option
- Changed Options Add implementation to work like the maybe Monad (return None if any of the inputs is None)  
  See https://github.com/mozilla/rust/issues/6002, especially my last comment.
- Removed duplicate Option::get and renamed all related functions to use the term `unwrap` instead  
  See also https://github.com/mozilla/rust/issues/7887.

Todo: 

Adding testcases for all function in the three modules. Even without the few functions I added, the coverage wasn't complete to begin with. But I'd rather do that as a follow up PR, I've touched to much code here already, need to go through them again later.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index afa2e7a5e42..a0932729930 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -691,7 +691,7 @@ impl Parser {
         */
 
         let opt_abis = self.parse_opt_abis();
-        let abis = opt_abis.get_or_default(AbiSet::Rust());
+        let abis = opt_abis.unwrap_or_default(AbiSet::Rust());
         let purity = self.parse_unsafety();
         self.expect_keyword(keywords::Fn);
         let (decl, lifetimes) = self.parse_ty_fn_decl();
@@ -3326,7 +3326,7 @@ impl Parser {
         let ident = self.parse_ident();
         let opt_bounds = self.parse_optional_ty_param_bounds();
         // For typarams we don't care about the difference b/w "<T>" and "<T:>".
-        let bounds = opt_bounds.get_or_default(opt_vec::Empty);
+        let bounds = opt_bounds.unwrap_or_default(opt_vec::Empty);
         ast::TyParam { ident: ident, id: self.get_id(), bounds: bounds }
     }
 
@@ -4196,7 +4196,7 @@ impl Parser {
                 self.obsolete(*self.last_span, ObsoleteExternVisibility);
             }
 
-            let abis = opt_abis.get_or_default(AbiSet::C());
+            let abis = opt_abis.unwrap_or_default(AbiSet::C());
 
             let (inner, next) = self.parse_inner_attrs_and_next();
             let m = self.parse_foreign_mod_items(sort, abis, next);
@@ -4463,7 +4463,7 @@ impl Parser {
 
             if self.eat_keyword(keywords::Fn) {
                 // EXTERN FUNCTION ITEM
-                let abis = opt_abis.get_or_default(AbiSet::C());
+                let abis = opt_abis.unwrap_or_default(AbiSet::C());
                 let (ident, item_, extra_attrs) =
                     self.parse_item_fn(extern_fn, abis);
                 return iovi_item(self.mk_item(lo, self.last_span.hi, ident,