view mercurial/encoding.py @ 9051:f8e25885d975

commands: wrapped docstrings at 78 characters

We have always had a left margin of 4 characters -- probably just
because that's how docstrings for top-level functions turn out by
default, but it also looks nice in the built-in help.

The docstrings were wrapped at 70 characters, which is the default for
Emacs. However, this gives a right margin of 10 characters in a
standard 80 character terminal.

I've now wrapped the relevant docstrings at 78 characters, effectively
killing the right margin. The asymmetric margins looked a bit odd and
some of the text looked cramped with a right margin, so Dirkjan and I
felt that it was best to remove it entirely. The two character gap was
kept to have some space between the border of the terminal -- it will
also make diffs involving the docstrings fit in a 80 character line.

# encoding.py - character transcoding support for Mercurial
#
#  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

import error
import sys, unicodedata, locale, os

_encodingfixup = {'646': 'ascii', 'ANSI_X3.4-1968': 'ascii'}

try:
    encoding = os.environ.get("HGENCODING")
    if sys.platform == 'darwin' and not encoding:
        # On darwin, getpreferredencoding ignores the locale environment and
        # always returns mac-roman. We override this if the environment is
        # not C (has been customized by the user).
        locale.setlocale(locale.LC_CTYPE, '')
        encoding = locale.getlocale()[1]
    if not encoding:
        encoding = locale.getpreferredencoding() or 'ascii'
        encoding = _encodingfixup.get(encoding, encoding)
except locale.Error:
    encoding = 'ascii'
encodingmode = os.environ.get("HGENCODINGMODE", "strict")
fallbackencoding = 'ISO-8859-1'

def tolocal(s):
    """
    Convert a string from internal UTF-8 to local encoding

    All internal strings should be UTF-8 but some repos before the
    implementation of locale support may contain latin1 or possibly
    other character sets. We attempt to decode everything strictly
    using UTF-8, then Latin-1, and failing that, we use UTF-8 and
    replace unknown characters.
    """
    for e in ('UTF-8', fallbackencoding):
        try:
            u = s.decode(e) # attempt strict decoding
            return u.encode(encoding, "replace")
        except LookupError, k:
            raise error.Abort("%s, please check your locale settings" % k)
        except UnicodeDecodeError:
            pass
    u = s.decode("utf-8", "replace") # last ditch
    return u.encode(encoding, "replace")

def fromlocal(s):
    """
    Convert a string from the local character encoding to UTF-8

    We attempt to decode strings using the encoding mode set by
    HGENCODINGMODE, which defaults to 'strict'. In this mode, unknown
    characters will cause an error message. Other modes include
    'replace', which replaces unknown characters with a special
    Unicode character, and 'ignore', which drops the character.
    """
    try:
        return s.decode(encoding, encodingmode).encode("utf-8")
    except UnicodeDecodeError, inst:
        sub = s[max(0, inst.start-10):inst.start+10]
        raise error.Abort("decoding near '%s': %s!" % (sub, inst))
    except LookupError, k:
        raise error.Abort("%s, please check your locale settings" % k)

def colwidth(s):
    "Find the column width of a UTF-8 string for display"
    d = s.decode(encoding, 'replace')
    if hasattr(unicodedata, 'east_asian_width'):
        w = unicodedata.east_asian_width
        return sum([w(c) in 'WF' and 2 or 1 for c in d])
    return len(d)