dag: rename binary_search_by to bsearch_by

Summary:
The name is being taken by stdlib:

  warning: a method with this name may be added to the standard library in the future
     --> eden/scm/lib/dag/src/spanset.rs:228:14
      |
  228 |             .binary_search_by(|probe| span.low.cmp(&probe.low))
      |              ^^^^^^^^^^^^^^^^
      |
      = note: `#[warn(unstable_name_collisions)]` on by default
      = warning: once this method is added to the standard library, the ambiguity may cause an error or change in behavior!
      = note: for more information, see issue #48919 <rust-lang/rust#48919>
      = help: call with fully qualified syntax `BinarySearchBy::binary_search_by(...)` to keep using the current method
      = help: add `#![feature(vecdeque_binary_search)]` to the crate attributes to enable `VecDeque::<T>::binary_search_by`

Reviewed By: sfilipco

Differential Revision: D26092424

fbshipit-source-id: d2cdf7d73d2f808f038817c9dc9f4c531ff643bd

Author: quark-zju

eden/scm/lib/dag/src/bsearch.rs

@@ -28,13 +28,13 @@ pub trait BinarySearchBy<T> {
     /// one of the matches could be returned. If the value is not found then
     /// [`Result::Err`] is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
-    fn binary_search_by<F>(&self, f: F) -> Result<usize, usize>
+    fn bsearch_by<F>(&self, f: F) -> Result<usize, usize>
     where
         F: FnMut(&T) -> Ordering;
 }
 
 impl<T> BinarySearchBy<T> for VecDeque<T> {
-    fn binary_search_by<F>(&self, mut f: F) -> Result<usize, usize>
+    fn bsearch_by<F>(&self, mut f: F) -> Result<usize, usize>
     where
         F: FnMut(&T) -> Ordering,
     {

eden/scm/lib/dag/src/spanset.rs

@@ -223,10 +223,7 @@ impl SpanSet {
     /// Tests if a given [`Id`] or [`Span`] is covered by this set.
     pub fn contains(&self, value: impl Into<Span>) -> bool {
         let span = value.into();
-        let idx = match self
-            .spans
-            .binary_search_by(|probe| span.low.cmp(&probe.low))
-        {
+        let idx = match self.spans.bsearch_by(|probe| span.low.cmp(&probe.low)) {
             Ok(idx) => idx,
             Err(idx) => idx,
         };
@@ -467,10 +464,7 @@ impl SpanSet {
     /// This is not a general purpose API, but useful for internal logic
     /// like DAG descendant calculation.
     pub(crate) fn intersection_span_min(&self, rhs: Span) -> Option<Id> {
-        let i = match self
-            .spans
-            .binary_search_by(|probe| rhs.low.cmp(&probe.high))
-        {
+        let i = match self.spans.bsearch_by(|probe| rhs.low.cmp(&probe.high)) {
             Ok(idx) => idx,
             Err(idx) => idx.max(1) - 1,
         };