X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=README;h=b9efea7b1d142a58bbcfafdf5b6cabea5daefe94;hb=6a204757f3b9c5d10bc57e21cbb65c0e29688066;hp=030eb08661306cc3101e6060724468f299272440;hpb=3c57941c660d64b4b3ad75b15d5afc8e9201f5d0;p=perl%2Fmodules%2FVariable-Magic.git diff --git a/README b/README index 030eb08..b9efea7 100644 --- a/README +++ b/README @@ -2,7 +2,7 @@ NAME Variable::Magic - Associate user-defined magic to variables from Perl. VERSION - Version 0.32 + Version 0.37 SYNOPSIS use Variable::Magic qw/wizard cast VMG_OP_INFO_NAME/; @@ -52,11 +52,12 @@ DESCRIPTION * It doesn't replace the original semantics. - Magic callbacks trigger before the original action take place, and - can't prevent it to happen. This makes catching individual events - easier than with "tie", where you have to provide fallbacks methods - for all actions by usually inheriting from the correct "Tie::Std*" - class and overriding individual methods in your own class. + Magic callbacks usually trigger before the original action take + place, and can't prevent it to happen. This also makes catching + individual events easier than with "tie", where you have to provide + fallbacks methods for all actions by usually inheriting from the + correct "Tie::Std*" class and overriding individual methods in your + own class. * It's type-agnostic. @@ -80,13 +81,13 @@ DESCRIPTION * "get" - This magic is invoked when the variable is evaluated (does not - include array/hash subscripts and slices). + This magic is invoked when the variable is evaluated. It is never + called for arrays and hashes. * "set" - This one is triggered each time the value of the variable changes - (includes array/hash subscripts and slices). + This one is triggered each time the value of the variable changes. + It is called for array subscripts and slices, but never for hashes. * "len" @@ -98,18 +99,16 @@ DESCRIPTION * "clear" - This magic is invoked when a container variable is reset, i.e. when - an array or a hash is emptied. Please note that this is different - from undefining the variable, even though the magic is called when - the clearing is a result of the undefine (e.g. for an array, but - actually a bug prevent it to work before perl 5.9.5 - see the - history). + This magic is invoked when the variable is reset, such as when an + array is emptied. Please note that this is different from undefining + the variable, even though the magic is called when the clearing is a + result of the undefine (e.g. for an array, but actually a bug + prevent it to work before perl 5.9.5 - see the history). * "free" This one can be considered as an object destructor. It happens when - the variable goes out of scope (with the exception of global scope), - but not when it is undefined. + the variable goes out of scope, but not when it is undefined. * "copy" @@ -229,7 +228,7 @@ FUNCTIONS $_[2] is an alias to the current key. Nothing prevents you from changing it, but be aware that there lurk dangerous - side effects. For example, it may righteously be readonly if + side effects. For example, it may rightfully be readonly if the key was a bareword. You can get a copy instead by passing "copy_key => 1" to "wizard", which allows you to safely assign to $_[2] in order to e.g. redirect the action @@ -271,15 +270,15 @@ FUNCTIONS This function associates $wiz magic to the variable supplied, without overwriting any other kind of magic. You can also supply the numeric signature $sig instead of $wiz. It returns true on success or when $wiz - magic is already present, 0 on error, and "undef" when no magic - corresponds to the given signature (in case $sig was supplied). All + magic is already present, and croaks on error or when no magic + corresponds to the given signature (in case a $sig was supplied). All extra arguments specified after $wiz are passed to the private data - constructor. If the variable isn't a hash, any "uvar" callback of the - wizard is safely ignored. + constructor in @_[1 .. @_-1]. If the variable isn't a hash, any "uvar" + callback of the wizard is safely ignored. - # Casts $wiz onto $x. If $wiz isn't a signature, undef can't be returned. + # Casts $wiz onto $x, and pass '1' to the data constructor. my $x; - die 'error' unless cast $x, $wiz; + cast $x, $wiz, 1; The "var" argument can be an array or hash value. Magic for those behaves like for any other scalar, except that it is dispelled when the @@ -341,24 +340,25 @@ FUNCTIONS getdata [$@%&*]var, [$wiz|$sig] This accessor fetches the private data associated with the magic $wiz - (or the signature $sig) in the variable. "undef" is returned when no - such magic or data is found, or when $sig does not represent a current - valid magic object. + (or the signature $sig) in the variable. It croaks when $wiz or $sig do + not represent a valid magic object, and returns an empty list if no such + magic is attached to the variable or when the wizard has no data + constructor. - # Get the attached data. - my $data = getdata $x, $wiz or die 'no such magic or magic has no data'; + # Get the attached data, or undef if the wizard does not attach any. + my $data = getdata $x, $wiz; "dispell" dispell [$@%&*]variable, [$wiz|$sig] The exact opposite of "cast" : it dissociates $wiz magic from the variable. You can also pass the magic signature $sig as the second - argument. True is returned on success, 0 on error or when no magic - represented by $wiz could be found in the variable, and "undef" when no - magic corresponds to the given signature (in case $sig was supplied). + argument. This function returns true on success, 0 when no magic + represented by $wiz or $sig could be found in the variable, and croaks + if the supplied wizard or signature is invalid. - # Dispell now. If $wiz isn't a signature, undef can't be returned. - die 'no such magic or error' unless dispell $x, $wiz; + # Dispell now. + die 'no such magic in $x' unless dispell $x, $wiz; CONSTANTS "SIG_MIN" @@ -406,6 +406,11 @@ CONSTANTS True iff this module could have been built with thread-safety features enabled. + "VMG_FORKSAFE" + True iff this module could have been built with fork-safety features + enabled. This will always be true except on Windows where it's false for + perl 5.10.0 and below . + "VMG_OP_INFO_NAME" Value to pass with "op_info" to get the current op name in the magic callbacks.