X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Foverload.pm;h=690be22175115742c8142118419525fbbc1d77e7;hb=a07cd53d52eddd3373b7f4babb55144d44a1613d;hp=99af00fadc29495984bb194e447f1249c9d5acc9;hpb=6d822dc4045278fb03135b2683bac92dba061369;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/overload.pm b/lib/overload.pm index 99af00f..690be22 100644 --- a/lib/overload.pm +++ b/lib/overload.pm @@ -1,8 +1,6 @@ package overload; -our $VERSION = '1.00'; - -$overload::hint_bits = 0x20000; +our $VERSION = '1.04'; sub nil {} @@ -84,18 +82,17 @@ sub Method { sub AddrRef { my $package = ref $_[0]; return "$_[0]" unless $package; - bless $_[0], overload::Fake; # Non-overloaded package - my $str = "$_[0]"; - bless $_[0], $package; # Back - $package . substr $str, index $str, '='; -} -sub StrVal { - (ref $_[0] && OverloadedStringify($_[0]) or ref($_[0]) eq 'Regexp') ? - (AddrRef(shift)) : - "$_[0]"; + require Scalar::Util; + my $class = Scalar::Util::blessed($_[0]); + my $class_prefix = defined($class) ? "$class=" : ""; + my $type = Scalar::Util::reftype($_[0]); + my $addr = Scalar::Util::refaddr($_[0]); + return sprintf("$class_prefix$type(0x%x)", $addr); } +*StrVal = *AddrRef; + sub mycan { # Real can would leave stubs. my ($package, $meth) = @_; return \*{$package . "::$meth"} if defined &{$package . "::$meth"}; @@ -108,11 +105,11 @@ sub mycan { # Real can would leave stubs. } %constants = ( - 'integer' => 0x1000, - 'float' => 0x2000, - 'binary' => 0x4000, - 'q' => 0x8000, - 'qr' => 0x10000, + 'integer' => 0x1000, # HINT_NEW_INTEGER + 'float' => 0x2000, # HINT_NEW_FLOAT + 'binary' => 0x4000, # HINT_NEW_BINARY + 'q' => 0x8000, # HINT_NEW_STRING + 'qr' => 0x10000, # HINT_NEW_RE ); %ops = ( with_assign => "+ - * / % ** << >> x .", @@ -150,7 +147,7 @@ sub constant { } else { $^H{$_[0]} = $_[1]; - $^H |= $constants{$_[0]} | $overload::hint_bits; + $^H |= $constants{$_[0]}; } shift, shift; } @@ -171,7 +168,7 @@ __END__ =head1 NAME -overload - Package for overloading perl operations +overload - Package for overloading Perl operations =head1 SYNOPSIS @@ -423,7 +420,7 @@ The dereference operators must be specified explicitly they will not be passed t =item * I - "nomethod", "fallback", "=", + "nomethod", "fallback", "=", "~~", see L>. @@ -543,6 +540,11 @@ C<"nomethod"> value, and if this is missing, raises an exception. B C<"fallback"> inheritance via @ISA is not carved in stone yet, see L<"Inheritance and overloading">. +=head2 Smart Match + +The key C<"~~"> allows you to override the smart matching used by +the switch construct. See L. + =head2 Copy Constructor The value for C<"="> is a reference to a function with three @@ -664,6 +666,23 @@ value is a scalar and not a reference. =back +=head1 Minimal set of overloaded operations + +Since some operations can be automatically generated from others, there is +a minimal set of operations that need to be overloaded in order to have +the complete set of overloaded operations at one's disposal. +Of course, the autogenerated operations may not do exactly what the user +expects. See L above. The minimal set is: + + + - * / % ** << >> x + <=> cmp + & | ^ ~ + atan2 cos sin exp log sqrt int + +Additionally, you need to define at least one of string, boolean or +numeric conversions because any one can be used to emulate the others. +The string conversion can also be used to emulate concatenation. + =head1 Losing overloading The restriction for the comparison operation is that even if, for example, @@ -701,7 +720,10 @@ Package C provides the following public functions: =item overload::StrVal(arg) -Gives string value of C as in absence of stringify overloading. +Gives string value of C as in absence of stringify overloading. If you +are using this to get the address of a reference (useful for checking if two +references point to the same thing) then you may be better off using +C, which is faster. =item overload::Overloaded(arg) @@ -715,12 +737,12 @@ Returns C or a reference to the method that implements C. =head1 Overloading constants -For some application Perl parser mangles constants too much. It is possible -to hook into this process via overload::constant() and overload::remove_constant() -functions. +For some applications, the Perl parser mangles constants too much. +It is possible to hook into this process via C +and C functions. These functions take a hash as an argument. The recognized keys of this hash -are +are: =over 8 @@ -776,9 +798,6 @@ From these methods they may be called as overload::constant integer => sub {Math::BigInt->new(shift)}; } -B Currently overloaded-ness of constants does not propagate -into C. - =head1 IMPLEMENTATION What follows is subject to change RSN. @@ -1084,7 +1103,7 @@ The value of $side is Note that while we obtained this value using a nice little script, there is no simple way to I this value. In fact this value may -be inspected in debugger (see L), but ony if +be inspected in debugger (see L), but only if C Bption is set, and not via C

command. If one attempts to print this value, then the overloaded operator