mercurial/strutil.py

ui: add new config flag for interface selection

This patch introduces a new config flag ui.interface to select the interface
for interactive commands. It currently only applies to chunks selection.
The config can be overridden on a per feature basis with the flag
ui.interface.<feature>.

features for the moment can only be 'chunkselector', moving forward we expect
to have 'histedit' and other commands there.

If an incorrect value is given to ui.interface we print a warning and use the
default interface: text. If HGPLAIN is specified we also use the default
interface: text.

Note that we fail quickly if a feature does not handle all the interfaces
that we permit in ui.interface; in future, we could design a fallback path
(e.g. blackpearl to curses, curses to text), but let's leave that until we
need it.

# 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.

from __future__ import absolute_import

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