Comments on: Perl Aliases & Dynamically Scoped Variables http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/ Screams in the Night Thu, 20 Nov 2008 14:28:12 +0000 http://wordpress.org/?v=2.2.2 By: Bill http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-573 Bill Mon, 29 Aug 2005 03:37:29 +0000 http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-573 Limiting my poor verbal form to just today is too kind. ;) Limiting my poor verbal form to just today is too kind. ;)

]]> By: Jeffrey Friedl http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-572 Jeffrey Friedl Sun, 28 Aug 2005 21:00:44 +0000 http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-572 Oh, I guess I see what you mean. You're not in good verbal form today, though, as the value of any non-constant variable tends to depend on the execution path, no? :-) "local" is an action which has no influence on the scope of the variable (on where in the code the variable is accessable from). It merely makes a copy of the current value and schedules that copied value to be put back at the close of the current lexical scope. You could consider that the varialble's *value* has been dynamically scoped, an issue which seems unrelated to your original post about making aliases. I'm curious to look at Lexical::Alias to see how it was done. In pure Perl, I figure it'd have to be done with a tied variable or, gee, perhaps overloading could do it? It's not something I ever recall having needed.... Oh, I guess I see what you mean. You’re not in good verbal form today, though, as the value of any non-constant variable tends to depend on the execution path, no? :-)

“local” is an action which has no influence on the scope of the variable (on where in the code the variable is accessable from). It merely makes a copy of the current value and schedules that copied value to be put back at the close of the current lexical scope. You could consider that the varialble’s *value* has been dynamically scoped, an issue which seems unrelated to your original post about making aliases.

I’m curious to look at Lexical::Alias to see how it was done. In pure Perl, I figure it’d have to be done with a tied variable or, gee, perhaps overloading could do it? It’s not something I ever recall having needed….

]]> By: Bill http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-571 Bill Sun, 28 Aug 2005 16:24:42 +0000 http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-571 I think using 'local' was refered to a dynamic as the value can depend upon a particular path of execution? I think using ‘local’ was refered to a dynamic as the value can depend upon a particular path of execution?

]]> By: Jeffrey Friedl http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-570 Jeffrey Friedl Sun, 28 Aug 2005 13:20:41 +0000 http://wdr1.com/blog/2005/08/27/perl-aliases-dynamically-scoped-variables/#comment-570 What is dynamic about the scope of any perl variable? All named variables are statically scoped ('my' variables are visible from within a specific lexical scope defined at compile time; global variables are visible from everywhere). What is dynamic about the scope of any perl variable? All named variables are statically scoped (’my’ variables are visible from within a specific lexical scope defined at compile time; global variables are visible from everywhere).

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