NAMEex::debugging - Simple debugging in your code with compile-time constants SYNOPSIS use ex::debugging +DEBUGLEVEL;
use ex::debugging -DEBUGLEVEL;
use ex::debugging; # defaults to DEBUGLEVEL +1;
no ex::debugging;
Please, note, this will not work (because of explicit empty list doesn't call import): use ex::debugging ();
no ex::debugging ();DESCRIPTIONex::debugging was designed to replace commonly used warn sprintf ... if $DEBUG There are two interfaces the same time: functional and OO; Functional styleHave some unclear restriction: There MUST be a + or - sign after the debug function. Otherwise, you'll get syntax error, when debugging will be disabled. debug + LEVEL, EXPR, LIST;::
Writes message to debug log (default - STDERR). Message will be created using sprintf EXPR,LIST. LIST will be remapped, so you'll see the undef as " <undef> " and empty string as "''" Examples: debug+0 => 'my test: %s',$var;
# Produces to STDERR something like:
# [main:10:] my test: <undef>Current default output format is: [ PACKAGE, LINE, SUB ] MESSAGE The sub will be get from stack, untill it differs from ANON. So you'll se (if not called from main::) the first named sub. OO styleUses autocreated function d to access the debugging object. It defines 5 methods: debug, info, log, warn, error with the levels 2..-2 respective. Also there are a definition of assert d->debug('my test: %s',$var); # equivalent to debug+2 => 'my test: %s', $var;
d->warn('something wrong with me'); # equivalent to debug-1 => '...';Also, methods warn and error will work, even if no ex::debugging in effect. Old styleAlso this module provides well known constant DEBUG, which will work even at compile time warn "Something" if DEBUG;
# will be threated as C<warn "Something"> when DEBUG in effect
# and as nothing when DEBUG is not in effectPERFOMANCEDefault routines give very small overhead, much smaller than call to empty subroutine, but the fastest way with no overhead at all is the old well known if DEBUG. Sad but true debug+0 => 'fastest debug' if DEBUG;
assert+0 => 1==2, 'fastest assert' if DEBUG;
d->assert(1==2,'fastest assert') if DEBUG;EXPORTSThis package implicitly exports to the caller's namespace next subroutines: DEBUG, debug, d CAVEATSNOT SCOPEDThe pragma is a per script, not a per block lexical. Only the last use ex::debugging or no ex::debugging matters, and it affects '''the whole script'''. The multiple use of this pragma is discouraged. REQUIREMENTS OF SIGNFunctional style uses compile-time hack, and when no debugging in effect, function debug replaced with 0; So the statement debug+0 = ...> converts to 0+0, ... (May be checked using B::Deparse) When use debugging is in effect debug+0 = ...> converts to debug( +0, ... ) Without a sign '''the syntax is erroneous''' when no debugging: 0 0, ... If somebody knows, how to hack this (without source filters ;), let me know. COLLISIONSThis package can't be used together with Carp::Assert. AUTHORMons Anderson <inthrax@gmail.com>
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