Re: [perl #130038] Builtin variable for loop index in foreach

On Mon, Nov 28, 2016 at 08:14:23PM +1300, Kent Fredric wrote:
> At parse time, the Perl compiler parsing the for { } block *lexically*
> parses for a variable ( we'll just say $# for now ).
> 
> And then upon detecting that variable's usage in its block, then instruments
> the for loop to behave differently.

what about:

    for (...) {
        eval '$#';
    }

> Also, my memory tells me lexicals are rather fast in comparison to
> globals, but my memory could be wrong.

Marginally faster. For example '$x = 1' uses about 3% fewer CPU instructions
and 2% fewer data reads when $x is lexical.

-- 
This is a great day for France!
    -- Nixon at Charles De Gaulle's funeral

• [perl #130038] Builtin variable for loop index in foreach by Ed Avis
• Re: [perl #130038] Builtin variable for loop index in foreach by Dave Mitchell
• Re: [perl #130038] Builtin variable for loop index in foreach by Aristotle Pagaltzis
• Re: [perl #130038] Builtin variable for loop index in foreach by Kent Fredric
• Re: [perl #130038] Builtin variable for loop index in foreach by Dave Mitchell
• Re: [perl #130038] Builtin variable for loop index in foreach by Dave Mitchell
• Re: [perl #130038] Builtin variable for loop index in foreach by Kent Fredric
• Re: [perl #130038] Builtin variable for loop index in foreach by Kent Fredric
• [perl #130038] Builtin variable for loop index in foreach by Hugo van der Sanden via RT
• Re: [perl #130038] Builtin variable for loop index in foreach by Zefram
• Re: [perl #130038] Builtin variable for loop index in foreach by Dave Mitchell
• [perl #130038] Builtin variable for loop index in foreach by Ed Avis via RT
• RE: [perl #130038] Builtin variable for loop index in foreach by Ed Avis
• Re: [perl #130038] Builtin variable for loop index in foreach by demerphq
• Re: [perl #130038] Builtin variable for loop index in foreach by Dave Mitchell
• RE: [perl #130038] Builtin variable for loop index in foreach by Ed Avis