Re: eval() and lexical introspection in Parrot

[Mehmet Yavuz Selim Soyturk]

 One temporary workaround that I considered for this problem
 would be to have eval() use introspection on its caller to
 create a wrapper sub that duplicates the lexical environment of
 the caller, and then use that as the target of an :outer()
 flag when it's passed to imcc.  For example, the code
 passed to imcc would end up looking something like:

That workaround will not solve the problem for an assignment to a
lexical variable from evaluated code. Maybe it's not a problem for
Perl6 tests, though.

It would be good if there was an opcode Cset_outer inner_sub,
outer_sub to set the outer of a sub at runtime. I don't know if it's
possible/straightforward to implement though. Just assigning a new
value to Csub-outer_sub did not work for me before (segfault).


Mehmet Soyturk

Re: eval() and lexical introspection in Parrot

[Patrick R. Michaud]

On Wed, Dec 19, 2007 at 11:15:46PM +0100, Mehmet Yavuz Selim Soyturk wrote:
  One temporary workaround that I considered for this problem
  would be to have eval() use introspection on its caller to
  create a wrapper sub that duplicates the lexical environment of
  the caller, and then use that as the target of an :outer()
  flag when it's passed to imcc.  For example, the code
  passed to imcc would end up looking something like:
 
 That workaround will not solve the problem for an assignment to a
 lexical variable from evaluated code. Maybe it's not a problem for
 Perl6 tests, though.

Actually, it would.  The evaluated code would set the (outer)
lexical variable the same way that inner blocks currently do.

Pm

Re: eval() and lexical introspection in Parrot

[Patrick R. Michaud]

On Wed, Dec 19, 2007 at 10:57:27PM -0600, Patrick R. Michaud wrote:
 On Wed, Dec 19, 2007 at 11:15:46PM +0100, Mehmet Yavuz Selim Soyturk wrote:
   One temporary workaround that I considered for this problem
   would be to have eval() use introspection on its caller to
   create a wrapper sub that duplicates the lexical environment of
   the caller, and then use that as the target of an :outer()
   flag when it's passed to imcc.  For example, the code
   passed to imcc would end up looking something like:
  
  That workaround will not solve the problem for an assignment to a
  lexical variable from evaluated code. Maybe it's not a problem for
  Perl6 tests, though.
 
 Actually, it would.  The evaluated code would set the (outer)
 lexical variable the same way that inner blocks currently do.

On second thought, if you mean that evaluated code would not
be able to rebind an outer lexical variable, then you're
correct.  Simple assignment would continue to work, however.

Pm