| 1 | | | | | package base; |
| 2 | | | | | |
| 3 | | | | | use strict 'vars'; |
| 4 | | | | | use vars qw($VERSION); |
| 5 | | | | | $VERSION = '2.22'; |
| 6 | | | | | $VERSION = eval $VERSION; |
| 7 | | | | | |
| 8 | | | | | # constant.pm is slow |
| 9 | | | | | sub SUCCESS () { 1 } |
| 10 | | | | | |
| 11 | | | | | sub PUBLIC () { 2**0 } |
| 12 | | | | | sub PRIVATE () { 2**1 } |
| 13 | | | | | sub INHERITED () { 2**2 } |
| 14 | | | | | sub PROTECTED () { 2**3 } |
| 15 | | | | | |
| 16 | | | | | my $Fattr = \%fields::attr; |
| 17 | | | | | |
| 18 | | | | | sub has_fields { |
| 19 | | | | | my($base) = shift; |
| 20 | | | | | my $fglob = ${"$base\::"}{FIELDS}; |
| 21 | | | | | return( ($fglob && 'GLOB' eq ref($fglob) && *$fglob{HASH}) ? 1 : 0 ); |
| 22 | | | | | } |
| 23 | | | | | |
| 24 | | | | | sub has_attr { |
| 25 | | | | | my($proto) = shift; |
| 26 | | | | | my($class) = ref $proto || $proto; |
| 27 | | | | | return exists $Fattr->{$class}; |
| 28 | | | | | } |
| 29 | | | | | |
| 30 | | | | | sub get_attr { |
| 31 | | | | | $Fattr->{$_[0]} = [1] unless $Fattr->{$_[0]}; |
| 32 | | | | | return $Fattr->{$_[0]}; |
| 33 | | | | | } |
| 34 | | | | | |
| 35 | | | | | if ($] < 5.009) { |
| 36 | | | | | *get_fields = sub { |
| 37 | | | | | # Shut up a possible typo warning. |
| 38 | | | | | () = \%{$_[0].'::FIELDS'}; |
| 39 | | | | | my $f = \%{$_[0].'::FIELDS'}; |
| 40 | | | | | |
| 41 | | | | | # should be centralized in fields? perhaps |
| 42 | | | | | # fields::mk_FIELDS_be_OK. Peh. As long as %{ $package . '::FIELDS' } |
| 43 | | | | | # is used here anyway, it doesn't matter. |
| 44 | | | | | bless $f, 'pseudohash' if (ref($f) ne 'pseudohash'); |
| 45 | | | | | |
| 46 | | | | | return $f; |
| 47 | | | | | } |
| 48 | | | | | } |
| 49 | | | | | else { |
| 50 | | | | | *get_fields = sub { |
| 51 | | | | | # Shut up a possible typo warning. |
| 52 | | | | | () = \%{$_[0].'::FIELDS'}; |
| 53 | | | | | return \%{$_[0].'::FIELDS'}; |
| 54 | | | | | } |
| 55 | | | | | } |
| 56 | | | | | |
| 57 | | | | | if ($] < 5.008) { |
| 58 | | | | | *_module_to_filename = sub { |
| 59 | | | | | (my $fn = $_[0]) =~ s!::!/!g; |
| 60 | | | | | $fn .= '.pm'; |
| 61 | | | | | return $fn; |
| 62 | | | | | } |
| 63 | | | | | } |
| 64 | | | | | else { |
| 65 | | | | | *_module_to_filename = sub { |
| 66 | | | | | (my $fn = $_[0]) =~ s!::!/!g; |
| 67 | | | | | $fn .= '.pm'; |
| 68 | | | | | utf8::encode($fn); |
| 69 | | | | | return $fn; |
| 70 | | | | | } |
| 71 | | | | | } |
| 72 | | | | | |
| 73 | | | | | sub import { |
| 74 | | | | | my $class = shift; |
| 75 | | | | | |
| 76 | | | | | return SUCCESS unless @_; |
| 77 | | | | | |
| 78 | | | | | # List of base classes from which we will inherit %FIELDS. |
| 79 | | | | | my $fields_base; |
| 80 | | | | | |
| 81 | | | | | my $inheritor = caller(0); |
| 82 | | | | | |
| 83 | | | | | my @bases; |
| 84 | | | | | foreach my $base (@_) { |
| 85 | | | | | if ( $inheritor eq $base ) { |
| 86 | | | | | warn "Class '$inheritor' tried to inherit from itself\n"; |
| 87 | | | | | } |
| 88 | | | | | |
| 89 | | | | | next if grep $_->isa($base), ($inheritor, @bases); |
| 90 | | | | | |
| 91 | | | | | # Following blocks help isolate $SIG{__DIE__} changes |
| 92 | | | | | { |
| 93 | | | | | my $sigdie; |
| 94 | | | | | { |
| 95 | | | | | local $SIG{__DIE__}; |
| 96 | | | | | my $fn = _module_to_filename($base); |
| 97 | | | | | eval { require $fn }; |
| 98 | | | | | # Only ignore "Can't locate" errors from our eval require. |
| 99 | | | | | # Other fatal errors (syntax etc) must be reported. |
| 100 | | | | | # |
| 101 | | | | | # changing the check here is fragile - if the check |
| 102 | | | | | # here isn't catching every error you want, you should |
| 103 | | | | | # probably be using parent.pm, which doesn't try to |
| 104 | | | | | # guess whether require is needed or failed, |
| 105 | | | | | # see [perl #118561] |
| 106 | | | | | die if $@ && $@ !~ /^Can't locate \Q$fn\E .*? at .* line [0-9]+(?:, <[^>]*> (?:line|chunk) [0-9]+)?\.\n\z/s |
| 107 | | | | | || $@ =~ /Compilation failed in require at .* line [0-9]+(?:, <[^>]*> (?:line|chunk) [0-9]+)?\.\n\z/; |
| 108 | | | | | unless (%{"$base\::"}) { |
| 109 | | | | | require Carp; |
| 110 | | | | | local $" = " "; |
| 111 | | | | | Carp::croak(<<ERROR); |
| 112 | | | | | Base class package "$base" is empty. |
| 113 | | | | | (Perhaps you need to 'use' the module which defines that package first, |
| 114 | | | | | or make that module available in \@INC (\@INC contains: @INC). |
| 115 | | | | | ERROR |
| 116 | | | | | } |
| 117 | | | | | $sigdie = $SIG{__DIE__} || undef; |
| 118 | | | | | } |
| 119 | | | | | # Make sure a global $SIG{__DIE__} makes it out of the localization. |
| 120 | | | | | $SIG{__DIE__} = $sigdie if defined $sigdie; |
| 121 | | | | | } |
| 122 | | | | | push @bases, $base; |
| 123 | | | | | |
| 124 | | | | | if ( has_fields($base) || has_attr($base) ) { |
| 125 | | | | | # No multiple fields inheritance *suck* |
| 126 | | | | | if ($fields_base) { |
| 127 | | | | | require Carp; |
| 128 | | | | | Carp::croak("Can't multiply inherit fields"); |
| 129 | | | | | } else { |
| 130 | | | | | $fields_base = $base; |
| 131 | | | | | } |
| 132 | | | | | } |
| 133 | | | | | } |
| 134 | | | | | # Save this until the end so it's all or nothing if the above loop croaks. |
| 135 | | | | | push @{"$inheritor\::ISA"}, @bases; |
| 136 | | | | | |
| 137 | | | | | if( defined $fields_base ) { |
| 138 | | | | | inherit_fields($inheritor, $fields_base); |
| 139 | | | | | } |
| 140 | | | | | } |
| 141 | | | | | |
| 142 | | | | | sub inherit_fields { |
| 143 | | | | | my($derived, $base) = @_; |
| 144 | | | | | |
| 145 | | | | | return SUCCESS unless $base; |
| 146 | | | | | |
| 147 | | | | | my $battr = get_attr($base); |
| 148 | | | | | my $dattr = get_attr($derived); |
| 149 | | | | | my $dfields = get_fields($derived); |
| 150 | | | | | my $bfields = get_fields($base); |
| 151 | | | | | |
| 152 | | | | | $dattr->[0] = @$battr; |
| 153 | | | | | |
| 154 | | | | | if( keys %$dfields ) { |
| 155 | | | | | warn <<"END"; |
| 156 | | | | | $derived is inheriting from $base but already has its own fields! |
| 157 | | | | | This will cause problems. Be sure you use base BEFORE declaring fields. |
| 158 | | | | | END |
| 159 | | | | | |
| 160 | | | | | } |
| 161 | | | | | |
| 162 | | | | | # Iterate through the base's fields adding all the non-private |
| 163 | | | | | # ones to the derived class. Hang on to the original attribute |
| 164 | | | | | # (Public, Private, etc...) and add Inherited. |
| 165 | | | | | # This is all too complicated to do efficiently with add_fields(). |
| 166 | | | | | while (my($k,$v) = each %$bfields) { |
| 167 | | | | | my $fno; |
| 168 | | | | | if ($fno = $dfields->{$k} and $fno != $v) { |
| 169 | | | | | require Carp; |
| 170 | | | | | Carp::croak ("Inherited fields can't override existing fields"); |
| 171 | | | | | } |
| 172 | | | | | |
| 173 | | | | | if( $battr->[$v] & PRIVATE ) { |
| 174 | | | | | $dattr->[$v] = PRIVATE | INHERITED; |
| 175 | | | | | } |
| 176 | | | | | else { |
| 177 | | | | | $dattr->[$v] = INHERITED | $battr->[$v]; |
| 178 | | | | | $dfields->{$k} = $v; |
| 179 | | | | | } |
| 180 | | | | | } |
| 181 | | | | | |
| 182 | | | | | foreach my $idx (1..$#{$battr}) { |
| 183 | | | | | next if defined $dattr->[$idx]; |
| 184 | | | | | $dattr->[$idx] = $battr->[$idx] & INHERITED; |
| 185 | | | | | } |
| 186 | | | | | } |
| 187 | | | | | |
| 188 | | | | | 1; |
| 189 | | | | | |
| 190 | | | | | __END__ |
| 191 | | | | | |