X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Foverload.pm;h=425da1bf053b2fa8cce8d27aec6c578db52567c2;hb=1e9bd1186a044d6e3506ed14fbe055b8f75f7641;hp=a75c8179335e382de210a364bcac1e53c85fd76e;hpb=6a0e9e729887ef408896cb941e158abe23871017;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/overload.pm b/lib/overload.pm index a75c817..425da1b 100644 --- a/lib/overload.pm +++ b/lib/overload.pm @@ -1,8 +1,6 @@ package overload; -our $VERSION = '1.02'; - -$overload::hint_bits = 0x20000; # HINT_LOCALIZE_HH +our $VERSION = '1.07'; sub nil {} @@ -74,7 +72,13 @@ sub OverloadedStringify { sub Method { my $package = shift; - $package = ref $package if ref $package; + if(ref $package) { + local $@; + local $!; + require Scalar::Util; + $package = Scalar::Util::blessed($package); + return undef if !defined $package; + } #my $meth = $package->can('(' . shift); ov_method mycan($package, '(' . shift), $package; #return $meth if $meth ne \&nil; @@ -85,28 +89,31 @@ sub AddrRef { my $package = ref $_[0]; return "$_[0]" unless $package; - 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); + local $@; + local $!; + 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); } -sub StrVal { - (ref $_[0] && OverloadedStringify($_[0]) or ref($_[0]) eq 'Regexp') ? - (AddrRef(shift)) : - "$_[0]"; -} +*StrVal = *AddrRef; sub mycan { # Real can would leave stubs. my ($package, $meth) = @_; - return \*{$package . "::$meth"} if defined &{$package . "::$meth"}; - my $p; - foreach $p (@{$package . "::ISA"}) { - my $out = mycan($p, $meth); - return $out if $out; + + local $@; + local $!; + require mro; + + my $mro = mro::get_linear_isa($package); + foreach my $p (@$mro) { + my $fqmeth = $p . q{::} . $meth; + return \*{$fqmeth} if defined &{$fqmeth}; } + return undef; } @@ -123,7 +130,7 @@ sub mycan { # Real can would leave stubs. num_comparison => "< <= > >= == !=", '3way_comparison'=> "<=> cmp", str_comparison => "lt le gt ge eq ne", - binary => "& | ^", + binary => '& &= | |= ^ ^=', unary => "neg ! ~", mutators => '++ --', func => "atan2 cos sin exp abs log sqrt int", @@ -153,7 +160,7 @@ sub constant { } else { $^H{$_[0]} = $_[1]; - $^H |= $constants{$_[0]} | $overload::hint_bits; + $^H |= $constants{$_[0]}; } shift, shift; } @@ -174,7 +181,7 @@ __END__ =head1 NAME -overload - Package for overloading perl operations +overload - Package for overloading Perl operations =head1 SYNOPSIS @@ -356,13 +363,17 @@ arrays, C is used to compare values subject to C. =item * I - "&", "^", "|", "neg", "!", "~", + "&", "&=", "^", "^=", "|", "|=", "neg", "!", "~", C stands for unary minus. If the method for C is not specified, it can be autogenerated using the method for subtraction. If the method for C is not specified, it can be autogenerated using the methods for C, or C<"">, or C<0+>. +The same remarks in L<"Arithmetic operations"> about +assignment-variants and autogeneration apply for +bit operations C<"&">, C<"^">, and C<"|"> as well. + =item * I "++", "--", @@ -426,7 +437,7 @@ The dereference operators must be specified explicitly they will not be passed t =item * I - "nomethod", "fallback", "=", + "nomethod", "fallback", "=", "~~", see L>. @@ -443,7 +454,7 @@ A computer-readable form of the above table is available in the hash num_comparison => '< <= > >= == !=', '3way_comparison'=> '<=> cmp', str_comparison => 'lt le gt ge eq ne', - binary => '& | ^', + binary => '& &= | |= ^ ^=', unary => 'neg ! ~', mutators => '++ --', func => 'atan2 cos sin exp abs log sqrt', @@ -546,6 +557,11 @@ 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 @@ -576,7 +592,8 @@ appear as lvalue when the above code is executed. If the copy constructor is required during the execution of some mutator, but a method for C<'='> was not specified, it can be autogenerated as a -string copy if the object is a plain scalar. +string copy if the object is a plain scalar or a simple assignment if it +is not. =over 5 @@ -663,10 +680,28 @@ C=E> or C: =item I can be expressed in terms of an assignment to the dereferenced value, if this -value is a scalar and not a reference. +value is a scalar and not a reference, or simply a reference assignment +otherwise. =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, @@ -721,12 +756,12 @@ 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 @@ -782,9 +817,6 @@ 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. @@ -1090,7 +1122,7 @@ 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