Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister

Re: On Compilation, Call Trigger Policy: Now vs Inline

by sh1tn (Priest)
on Dec 06, 2007 at 13:45 UTC ( #655400=note: print w/replies, xml ) Need Help??

in reply to On Compilation, Call Trigger Policy: Now vs Inline

It is written:If you think of an eval STRING as a call back from the interpreter to the compiler, then you might think of a BEGIN as a call forward from the compiler into the interpreter. Both temporarily put the current activity on hold and switch modes of operation.

Pretty self-explanatory.
print "start main running here\n"; eval "BEGIN{print qq(BEGIN: before eval compilation at run-time +\n)} END{print qq(END: from eval STRING\n)}"; eval {BEGIN{print qq(BEGIN: before eval compilation at compile-t +ime\n)} END{print qq(END: from eval BLOCK\n)}}; END { print "END: done running\n" } BEGIN { print "BEGIN: still compiling\n" }

Replies are listed 'Best First'.
Re^2: On Compilation, Call Trigger Policy: Now vs Inline
by ian (Beadle) on Dec 06, 2007 at 17:26 UTC
    I'm in agreement about the straightforwardness of call back and call forward with respect to interpreter->compiler and compiler->interpreter; it's the difference between the call trigger policy of "Now" vs "Inline" that's confusing to me. Is it merely that BEGIN is always triggered at the beginning of the line versus an eval which can be triggered anywhere within one?
    -- Ian Tegebo

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://655400]
[davido]: If you ever doubt the progress made in CPU technology: I have a script that runs in 2m20s on a Core2-Duo with 8GB RAM and an SSD. On an i7-2700K, also with SSD, same script runs in 12.5s.
[davido]: That's a 2nd Gen i7, but it is OC'ed from 3.5GHz to 4.6. ...things break down for awhile following 2nd gen though; the 2nd gen i7 2700k beats my Haswell (4th gen) i7 laptop by about 30%

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (11)
As of 2017-11-22 15:11 GMT
Find Nodes?
    Voting Booth?
    In order to be able to say "I know Perl", you must have:

    Results (326 votes). Check out past polls.