On Wed, May 04, 2005 at 02:22:43PM -0400, John Macdonald wrote: > On Wed, May 04, 2005 at 10:43:22AM -0400, Aaron Sherman wrote: > > On Wed, 2005-05-04 at 10:07, Aaron Sherman wrote: > > > A coroutine is just a functional unit that can be re-started after a > > > previous return, so I would expect that in Perl, a coroutine would be > > > defined by the use of a variant of return > > A co(operating) routine is similar to a sub(ordinate) routine. > They are both a contained unit of code that can be invoked. > > A subroutine carries out its entire functionality completely > and then terminates before returning control back to the caller. > [...] > This can be used for a large variety of functions. > The most common (and what people sometimes believe the > *only* usage) is as a generator - a coroutime which creates a > sequence of values as its "chunk" and always returns control > to its caller. ...
Notably, the grammar engine for Perl 6 rules is taking full advantage of Parrot coroutines. Invoking a rule (coroutine) causes the rule to continue until it completes a match, at which point it returns the results of the match to the caller. But the caller can later return control back to the rule/match so that the matching (and backtracking) continues from where it last finished. Pm
