intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 80 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Lib/bisect.py b/contrib/tools/python3/src/Lib/bisect.py
new file mode 100644
index 00000000000..8f3f6a3fe35
--- /dev/null
+++ b/contrib/tools/python3/src/Lib/bisect.py
@@ -0,0 +1,80 @@
+"""Bisection algorithms."""
+
+def insort_right(a, x, lo=0, hi=None):
+    """Insert item x in list a, and keep it sorted assuming a is sorted.
+
+    If x is already in a, insert it to the right of the rightmost x.
+
+    Optional args lo (default 0) and hi (default len(a)) bound the
+    slice of a to be searched.
+    """
+
+    lo = bisect_right(a, x, lo, hi)
+    a.insert(lo, x)
+
+def bisect_right(a, x, lo=0, hi=None):
+    """Return the index where to insert item x in list a, assuming a is sorted.
+
+    The return value i is such that all e in a[:i] have e <= x, and all e in
+    a[i:] have e > x.  So if x already appears in the list, a.insert(x) will
+    insert just after the rightmost x already there.
+
+    Optional args lo (default 0) and hi (default len(a)) bound the
+    slice of a to be searched.
+    """
+
+    if lo < 0:
+        raise ValueError('lo must be non-negative')
+    if hi is None:
+        hi = len(a)
+    while lo < hi:
+        mid = (lo+hi)//2
+        # Use __lt__ to match the logic in list.sort() and in heapq
+        if x < a[mid]: hi = mid
+        else: lo = mid+1
+    return lo
+
+def insort_left(a, x, lo=0, hi=None):
+    """Insert item x in list a, and keep it sorted assuming a is sorted.
+
+    If x is already in a, insert it to the left of the leftmost x.
+
+    Optional args lo (default 0) and hi (default len(a)) bound the
+    slice of a to be searched.
+    """
+
+    lo = bisect_left(a, x, lo, hi)
+    a.insert(lo, x)
+
+
+def bisect_left(a, x, lo=0, hi=None):
+    """Return the index where to insert item x in list a, assuming a is sorted.
+
+    The return value i is such that all e in a[:i] have e < x, and all e in
+    a[i:] have e >= x.  So if x already appears in the list, a.insert(x) will
+    insert just before the leftmost x already there.
+
+    Optional args lo (default 0) and hi (default len(a)) bound the
+    slice of a to be searched.
+    """
+
+    if lo < 0:
+        raise ValueError('lo must be non-negative')
+    if hi is None:
+        hi = len(a)
+    while lo < hi:
+        mid = (lo+hi)//2
+        # Use __lt__ to match the logic in list.sort() and in heapq
+        if a[mid] < x: lo = mid+1
+        else: hi = mid
+    return lo
+
+# Overwrite above definitions with a fast C implementation
+try:
+    from _bisect import *
+except ImportError:
+    pass
+
+# Create aliases
+bisect = bisect_right
+insort = insort_right