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Hello list,

I am trying to reimplement in LPeg a recursive-descent parser that I
wrote by hand, and - for some reasons that I'll explain in a next
message if it turns out that my doubts are not too dumb - I had to use
lpeg.Cmt(f) in several of my sub-patterns, and I realized that my work
would be much easier if lpeg.Cp accepted a pattern as an argument,
i.e., if instead of

  lpeg.C(patt)  the match for patt plus all captures made by patt
  lpeg.Cp()     the current position (matches the empty string)

we had:

  lpeg.C(patt)  the match for patt plus all captures made by patt
  lpeg.Cp(patt) if patt is nil, then the current position;
                if patt is a pattern, then the position after
                matching patt (if the match succeeds), plus all
                captures made by patt

Anyone knows a way to simulate the behavior I'm suggesting for lpeg.Cp
when its `patt' is not nil?

  Cheers and thanks in advance,
    Eduardo Ochs

P.S.: I _think_ I know two ways for doing that: one is a very, very,
_very_ ugly hack using the fact that `patt / f' is supposed to
evaluates f as late as possible (modulo optimizations), and the other
way involves running table.pack on the captures of patt*lpeg.Cp(),
then returning the last value in that table plus the unpacking of the
rest... But there must be better ways! =|