map reduce with redo: apenwarr #2

default.stamp.do

redo-ifchange $1.data
echo $1.data >>needs-reduce

do-reduce

#!/bin/sh
echo $ARGV

reduce.do

for d in *.data; do
  echo "${d%.data}.stamp"
done | xargs redo-ifchange
sh do-reduce $(sort needs-reduce | uniq) > $3
cat did-reduce needs-reduce | sort | uniq >did-reduce.new
mv did-reduce.new did-reduce
rm -f needs-reduce