The worker-wrapper component of the Stratego optimizer splits strategy definitions into a wrapper performing a pattern match, and a worker doing the real work of the operator. That is, a definition of the form

  f(as1 | as2) = {xs : ?t ; s}

is split into the pair of definitions

  f(as1 | as2) = {xs : ?t ; g(as1 | as2, xs)}
  g(as1 | as2, xs) = s

Thus f is reduced to a small definition comprising only a match and a call to the continuation g. The smaller definition for f becomes attractive to inline, especially in the context of a choice where pattern match compilation may integrate it with other matches, or in the context of a build, which may cancel against the match ?t.

-- EelcoVisser - 17 Aug 2003