recognize the <a b c> form of alternation

[coke]

 Original report.

Original Post:

A <?before> rule with a space between the '<' and the '?' compiles
but fails at execution
with the unhelpful message :
Unable to find regex ''
Null PMC access in invoke()

-- 
cognominal stef

Followup:

I agree that this is not a useful error message. However, when
PGE is corrected to follow the specification the regex

< ?before foo>

would be identical to

'?before' | 'foo'

and no error message would be generated at all. 

(PGE hasn't been updated to recognize the < a b c > form of
alternation.)

Pm

[pmichaud]

PGE is now in maintenance / deprecation, so marking this ticket as "wontfix".

Pm