view mercurial/mdiff.py @ 13950:14d0553bd48b

help: do not show full help text for command on option errors

Example

  $ hg clone --jump foo bar
  hg clone: option --jump not recognized
  hg clone [OPTION]... SOURCE [DEST]

  make a copy of an existing repository

  options:

   -U --noupdate           the clone will include an empty working copy (only a
                           repository)
   -u --updaterev REV      revision, tag or branch to check out
   -r --rev REV [+]        include the specified changeset
   -b --branch BRANCH [+]  clone only the specified branch
      --pull               use pull protocol to copy metadata
      --uncompressed       use uncompressed transfer (fast over LAN)
   -e --ssh CMD            specify ssh command to use
      --remotecmd CMD      specify hg command to run on the remote side
      --insecure           do not verify server certificate (ignoring
                           web.cacerts config)

  [+] marked option can be specified multiple times

  use "hg help clone" to show the full help text

Motivation for this change

  If the user already has specified the command, he probably already knows
  the command to some extent. Apparently, he has a problem with the options,
  so we show him just the synopsis with the short help and the details about
  the options, with a hint on the last line how to get the full help text.

Why is Mercurial better with this change?

  Experts who just forgot about the details of an option don't get that
  much text thrown at them, while the newbies still get a hint on the last
  line how to get the full help text.

# mdiff.py - diff and patch routines for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[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 i18n import _
import bdiff, mpatch, util
import re, struct

def splitnewlines(text):
    '''like str.splitlines, but only split on newlines.'''
    lines = [l + '\n' for l in text.split('\n')]
    if lines:
        if lines[-1] == '\n':
            lines.pop()
        else:
            lines[-1] = lines[-1][:-1]
    return lines

class diffopts(object):
    '''context is the number of context lines
    text treats all files as text
    showfunc enables diff -p output
    git enables the git extended patch format
    nodates removes dates from diff headers
    ignorews ignores all whitespace changes in the diff
    ignorewsamount ignores changes in the amount of whitespace
    ignoreblanklines ignores changes whose lines are all blank
    upgrade generates git diffs to avoid data loss
    '''

    defaults = {
        'context': 3,
        'text': False,
        'showfunc': False,
        'git': False,
        'nodates': False,
        'ignorews': False,
        'ignorewsamount': False,
        'ignoreblanklines': False,
        'upgrade': False,
        }

    __slots__ = defaults.keys()

    def __init__(self, **opts):
        for k in self.__slots__:
            v = opts.get(k)
            if v is None:
                v = self.defaults[k]
            setattr(self, k, v)

        try:
            self.context = int(self.context)
        except ValueError:
            raise util.Abort(_('diff context lines count must be '
                               'an integer, not %r') % self.context)

    def copy(self, **kwargs):
        opts = dict((k, getattr(self, k)) for k in self.defaults)
        opts.update(kwargs)
        return diffopts(**opts)

defaultopts = diffopts()

def wsclean(opts, text, blank=True):
    if opts.ignorews:
        text = re.sub('[ \t\r]+', '', text)
    elif opts.ignorewsamount:
        text = re.sub('[ \t\r]+', ' ', text)
        text = text.replace(' \n', '\n')
    if blank and opts.ignoreblanklines:
        text = re.sub('\n+', '', text)
    return text

def diffline(revs, a, b, opts):
    parts = ['diff']
    if opts.git:
        parts.append('--git')
    if revs and not opts.git:
        parts.append(' '.join(["-r %s" % rev for rev in revs]))
    if opts.git:
        parts.append('a/%s' % a)
        parts.append('b/%s' % b)
    else:
        parts.append(a)
    return ' '.join(parts) + '\n'

def unidiff(a, ad, b, bd, fn1, fn2, r=None, opts=defaultopts):
    def datetag(date, addtab=True):
        if not opts.git and not opts.nodates:
            return '\t%s\n' % date
        if addtab and ' ' in fn1:
            return '\t\n'
        return '\n'

    if not a and not b:
        return ""
    epoch = util.datestr((0, 0))

    if not opts.text and (util.binary(a) or util.binary(b)):
        if a and b and len(a) == len(b) and a == b:
            return ""
        l = ['Binary file %s has changed\n' % fn1]
    elif not a:
        b = splitnewlines(b)
        if a is None:
            l1 = '--- /dev/null%s' % datetag(epoch, False)
        else:
            l1 = "--- %s%s" % ("a/" + fn1, datetag(ad))
        l2 = "+++ %s%s" % ("b/" + fn2, datetag(bd))
        l3 = "@@ -0,0 +1,%d @@\n" % len(b)
        l = [l1, l2, l3] + ["+" + e for e in b]
    elif not b:
        a = splitnewlines(a)
        l1 = "--- %s%s" % ("a/" + fn1, datetag(ad))
        if b is None:
            l2 = '+++ /dev/null%s' % datetag(epoch, False)
        else:
            l2 = "+++ %s%s" % ("b/" + fn2, datetag(bd))
        l3 = "@@ -1,%d +0,0 @@\n" % len(a)
        l = [l1, l2, l3] + ["-" + e for e in a]
    else:
        al = splitnewlines(a)
        bl = splitnewlines(b)
        l = list(_unidiff(a, b, al, bl, opts=opts))
        if not l:
            return ""

        l.insert(0, "--- a/%s%s" % (fn1, datetag(ad)))
        l.insert(1, "+++ b/%s%s" % (fn2, datetag(bd)))

    for ln in xrange(len(l)):
        if l[ln][-1] != '\n':
            l[ln] += "\n\ No newline at end of file\n"

    if r:
        l.insert(0, diffline(r, fn1, fn2, opts))

    return "".join(l)

# creates a headerless unified diff
# t1 and t2 are the text to be diffed
# l1 and l2 are the text broken up into lines
def _unidiff(t1, t2, l1, l2, opts=defaultopts):
    def contextend(l, len):
        ret = l + opts.context
        if ret > len:
            ret = len
        return ret

    def contextstart(l):
        ret = l - opts.context
        if ret < 0:
            return 0
        return ret

    def yieldhunk(hunk):
        (astart, a2, bstart, b2, delta) = hunk
        aend = contextend(a2, len(l1))
        alen = aend - astart
        blen = b2 - bstart + aend - a2

        func = ""
        if opts.showfunc:
            # walk backwards from the start of the context
            # to find a line starting with an alphanumeric char.
            for x in xrange(astart - 1, -1, -1):
                t = l1[x].rstrip()
                if funcre.match(t):
                    func = ' ' + t[:40]
                    break

        yield "@@ -%d,%d +%d,%d @@%s\n" % (astart + 1, alen,
                                           bstart + 1, blen, func)
        for x in delta:
            yield x
        for x in xrange(a2, aend):
            yield ' ' + l1[x]

    if opts.showfunc:
        funcre = re.compile('\w')

    # bdiff.blocks gives us the matching sequences in the files.  The loop
    # below finds the spaces between those matching sequences and translates
    # them into diff output.
    #
    if opts.ignorews or opts.ignorewsamount:
        t1 = wsclean(opts, t1, False)
        t2 = wsclean(opts, t2, False)

    diff = bdiff.blocks(t1, t2)
    hunk = None
    for i, s1 in enumerate(diff):
        # The first match is special.
        # we've either found a match starting at line 0 or a match later
        # in the file.  If it starts later, old and new below will both be
        # empty and we'll continue to the next match.
        if i > 0:
            s = diff[i - 1]
        else:
            s = [0, 0, 0, 0]
        delta = []
        a1 = s[1]
        a2 = s1[0]
        b1 = s[3]
        b2 = s1[2]

        old = l1[a1:a2]
        new = l2[b1:b2]

        # bdiff sometimes gives huge matches past eof, this check eats them,
        # and deals with the special first match case described above
        if not old and not new:
            continue

        if opts.ignoreblanklines:
            if wsclean(opts, "".join(old)) == wsclean(opts, "".join(new)):
                continue

        astart = contextstart(a1)
        bstart = contextstart(b1)
        prev = None
        if hunk:
            # join with the previous hunk if it falls inside the context
            if astart < hunk[1] + opts.context + 1:
                prev = hunk
                astart = hunk[1]
                bstart = hunk[3]
            else:
                for x in yieldhunk(hunk):
                    yield x
        if prev:
            # we've joined the previous hunk, record the new ending points.
            hunk[1] = a2
            hunk[3] = b2
            delta = hunk[4]
        else:
            # create a new hunk
            hunk = [astart, a2, bstart, b2, delta]

        delta[len(delta):] = [' ' + x for x in l1[astart:a1]]
        delta[len(delta):] = ['-' + x for x in old]
        delta[len(delta):] = ['+' + x for x in new]

    if hunk:
        for x in yieldhunk(hunk):
            yield x

def patchtext(bin):
    pos = 0
    t = []
    while pos < len(bin):
        p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])
        pos += 12
        t.append(bin[pos:pos + l])
        pos += l
    return "".join(t)

def patch(a, bin):
    if len(a) == 0:
        # skip over trivial delta header
        return buffer(bin, 12)
    return mpatch.patches(a, [bin])

# similar to difflib.SequenceMatcher.get_matching_blocks
def get_matching_blocks(a, b):
    return [(d[0], d[2], d[1] - d[0]) for d in bdiff.blocks(a, b)]

def trivialdiffheader(length):
    return struct.pack(">lll", 0, 0, length)

patches = mpatch.patches
patchedsize = mpatch.patchedsize
textdiff = bdiff.bdiff