match: introduce boolean prefix() method
tl;dr: This is another step towards a (previously unstated) goal of
eliminating match.files() in conditions.
There are four types of matchers:
* always: Matches everything, checked with always(), files() is empty
* exact: Matches exact set of files, checked with isexact(), files()
contains the files to match
* patterns: Matches more complex patterns, checked with anypats(),
files() contains roots of the matched patterns
* prefix: Matches simple 'path:' patterns as prefixes ('foo' matches
both 'foo' and 'foo/bar'), no single method to check, files()
contains the prefixes to match
For completeness, it would be nice to have a method for checking for
the "prefix" type of matcher as well, so let's add that, making it
return True simply when none of the others do.
The larger goal here is to eliminate uses of match.files() in
conditions (i.e. bool(match.files())). The reason for this is that
there are scenarios when you would like to create a "prefix" matcher
that happens to match no files. One example is for 'hg files -I foo
bar'. The narrowmatcher also restricts the set of files given and it
would not surprise me if have bugs caused by that already. Note that
'if m.files() and not m.anypats()' and similar is sometimes used to
catch the "exact" and "prefix" cases above.
#!/usr/bin/env bash
# A simple script for opening merge conflicts in the editor.
# Use the following Mercurial settings to enable it.
#
# [ui]
# merge = editmerge
#
# [merge-tools]
# editmerge.args=$output
# editmerge.check=changed
# editmerge.premerge=keep
FILE=$1
getlines() {
grep -n "<<<<<<" $FILE | cut -f1 -d:
}
# editor preference loosely based on http://mercurial.selenic.com/wiki/editor
# hg showconfig is at the bottom though, since it's slow to run (0.15 seconds)
ED=$HGEDITOR
if [ "$ED" = "" ] ; then
ED=$VISUAL
fi
if [ "$ED" = "" ] ; then
ED=$EDITOR
fi
if [ "$ED" = "" ] ; then
ED=$(hg showconfig ui.editor)
fi
if [ "$ED" = "" ] ; then
echo "merge failed - unable to find editor"
exit 1
fi
if [ "$ED" = "emacs" ] || [ "$ED" = "nano" ] || [ "$ED" = "vim" ] ; then
FIRSTLINE=$(getlines | head -n 1)
PREVIOUSLINE=""
# open the editor to the first conflict until there are no more
# or the user stops editing the file
while [ ! "$FIRSTLINE" = "" ] && [ ! "$FIRSTLINE" = "$PREVIOUSLINE" ] ; do
$ED +$FIRSTLINE $FILE
PREVIOUSLINE=$FIRSTLINE
FIRSTLINE=$(getlines | head -n 1)
done
else
$ED $FILE
fi
# get the line numbers of the remaining conflicts
CONFLICTS=$(getlines | sed ':a;N;$!ba;s/\n/, /g')
if [ ! "$CONFLICTS" = "" ] ; then
echo "merge failed - resolve the conflicts (line $CONFLICTS) then use 'hg resolve --mark'"
exit 1
fi
exit 0