# Revision-checked byte edits of keyed documents. The runtime owns the
# documents: an edit is a transaction on the key's working version, which
# commits only if the sender's revision is still current.
state documents: bytes by key

input show = message by key
input edit = message by key {
  start: u32
  remove: u32
  insert: bytes
}

on show {
  reply documents[key]
}

on edit {
  documents[key].replace(edit.start .. edit.start + edit.remove, edit.insert)
  reply edit.insert
}