view mercurial/strutil.py @ 20613:10433163bf57

revset: add 'only' revset

Adds a only() revset that has two forms:

only(<set>) is equivalent to "::<set> - ::(heads() - heads(<set>::))"

only(<include>,<exclude>) is equivalent to "::<include> - ::<exclude>"

On a large repo, this implementation can process/traverse 50,000 revs in 0.7
seconds, versus 4.2 seconds using "::<include> - ::<exclude>".

This is useful for performing histedits on your branch:
hg histedit -r 'first(only(.))'

Or lifting branch foo off of branch bar:
hg rebase -d @ -s 'only(foo, bar)'

Or a variety of other uses.

# strutil.py - string utilities for Mercurial
#
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

def findall(haystack, needle, start=0, end=None):
    if end is None:
        end = len(haystack)
    if end < 0:
        end += len(haystack)
    if start < 0:
        start += len(haystack)
    while start < end:
        c = haystack.find(needle, start, end)
        if c == -1:
            break
        yield c
        start = c + 1

def rfindall(haystack, needle, start=0, end=None):
    if end is None:
        end = len(haystack)
    if end < 0:
        end += len(haystack)
    if start < 0:
        start += len(haystack)
    while end >= 0:
        c = haystack.rfind(needle, start, end)
        if c == -1:
            break
        yield c
        end = c - 1