contrib/editmerge

repository: define manifest interfaces

The long march towards declaring interfaces for repository
primitives continues.

This commit essentially defines interfaces based on the following
types:

* manifest.manifestdict -> imanifestdict
* manifest.manifestlog -> imanifestlog
* manifest.memmanifestctx -> imanifestrevisionwritable
* manifest.manifestctx -> imanifestrevisionstored
* manifest.memtreemanifestctx -> imanifestrevisionwritable
* manifest.treemanifestctx -> imanifestrevisionstored
* util.dirs -> idirs

The interfaces are thoroughly documented. Their documentation is
now better than the documentation in manifest.py in many cases.

With the exception of util.dirs, classes have been annotated with
their interfaces. (I didn't feel like util.dirs needed the
proper interface treatment.)

Tests have been added demonstrating that all classes and instances
conform to their interfaces.

This work was much easier than filelogs. That's because Durham
did an excellent job formalizing the manifest API a while back.

There are still some minor kludges with the interfaces that should
probably be addressed. But the primary goal with interface
declarations is getting something established. Once we have an
interface, we can modify it later easily enough.

Differential Revision: https://phab.mercurial-scm.org/D3869

#!/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 https://mercurial-scm.org/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