#!/bin/sh

cat > engine.py << EOF

from mercurial import templater

class mytemplater(object):
    def __init__(self, loader, filters, defaults):
        self.loader = loader

    def process(self, t, map):
        tmpl = self.loader(t)
        for k, v in map.iteritems():
            v = templater.stringify(v)
            tmpl = tmpl.replace('{{%s}}' % k, v)
        yield tmpl

templater.engines['my'] = mytemplater
EOF

hg init test
echo '[extensions]' > test/.hg/hgrc
echo "engine = $PWD/engine.py" >> test/.hg/hgrc

cd test
cat > mymap << EOF
changeset = my:changeset.txt
EOF

cat > changeset.txt << EOF
{{rev}} {{node}} {{author}}
EOF

hg ci -Ama
hg log --style=./mymap