Merge indexed_set.rs into bitvec.rs, and rename it bit_set.rs.

Currently we have two files implementing bitsets (and 2D bit matrices).
This commit combines them into one, taking the best features from each.

This involves renaming a lot of things. The high level changes are as
follows.
- bitvec.rs              --> bit_set.rs
- indexed_set.rs         --> (removed)
- BitArray + IdxSet      --> BitSet (merged, see below)
- BitVector              --> GrowableBitSet
- {,Sparse,Hybrid}IdxSet --> {,Sparse,Hybrid}BitSet
- BitMatrix              --> BitMatrix
- SparseBitMatrix        --> SparseBitMatrix

The changes within the bitset types themselves are as follows.

```
OLD             OLD             NEW
BitArray<C>     IdxSet<T>       BitSet<T>
--------        ------          ------
grow            -               grow
new             -               (remove)
new_empty       new_empty       new_empty
new_filled      new_filled      new_filled
-               to_hybrid       to_hybrid
clear           clear           clear
set_up_to       set_up_to       set_up_to
clear_above     -               clear_above
count           -               count
contains(T)     contains(&T)    contains(T)
contains_all    -               superset
is_empty        -               is_empty
insert(T)       add(&T)         insert(T)
insert_all      -               insert_all()
remove(T)       remove(&T)      remove(T)
words           words           words
words_mut       words_mut       words_mut
-               overwrite       overwrite
merge           union           union
-               subtract        subtract
-               intersect       intersect
iter            iter            iter
```

In general, when choosing names I went with:
- names that are more obvious (e.g. `BitSet` over `IdxSet`).
- names that are more like the Rust libraries (e.g. `T` over `C`,
  `insert` over `add`);
- names that are more set-like (e.g. `union` over `merge`, `superset`
  over `contains_all`, `domain_size` over `num_bits`).

Also, using `T` for index arguments seems more sensible than `&T` --
even though the latter is standard in Rust collection types -- because
indices are always copyable. It also results in fewer `&` and `*`
sigils in practice.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 2aaab6aaa16..68b46841718 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -46,7 +46,7 @@ extern crate smallvec;
 extern crate serialize as rustc_serialize; // used by deriving
 
 use rustc_data_structures::sync::Lock;
-use rustc_data_structures::bitvec::BitVector;
+use rustc_data_structures::bit_set::GrowableBitSet;
 pub use rustc_data_structures::small_vec::OneVector;
 pub use rustc_data_structures::thin_vec::ThinVec;
 use ast::AttrId;
@@ -82,8 +82,8 @@ macro_rules! unwrap_or {
 }
 
 pub struct Globals {
-    used_attrs: Lock<BitVector<AttrId>>,
-    known_attrs: Lock<BitVector<AttrId>>,
+    used_attrs: Lock<GrowableBitSet<AttrId>>,
+    known_attrs: Lock<GrowableBitSet<AttrId>>,
     syntax_pos_globals: syntax_pos::Globals,
 }
 
@@ -92,8 +92,8 @@ impl Globals {
         Globals {
             // We have no idea how many attributes their will be, so just
             // initiate the vectors with 0 bits. We'll grow them as necessary.
-            used_attrs: Lock::new(BitVector::new()),
-            known_attrs: Lock::new(BitVector::new()),
+            used_attrs: Lock::new(GrowableBitSet::new_empty()),
+            known_attrs: Lock::new(GrowableBitSet::new_empty()),
             syntax_pos_globals: syntax_pos::Globals::new(),
         }
     }