X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FPrototype%2FUtil.pm;h=efcd9749771bafbedce3173e8970a399da6a3422;hb=a0be79c11310f2a8e4edeca50e9ade6bd95b11d0;hp=73a1a60115f6d384ace73083584543d99bf60cc0;hpb=29d3a214c70390edd665985eddfb42ff7e29a02a;p=perl%2Fmodules%2FSub-Prototype-Util.git diff --git a/lib/Sub/Prototype/Util.pm b/lib/Sub/Prototype/Util.pm index 73a1a60..efcd974 100644 --- a/lib/Sub/Prototype/Util.pm +++ b/lib/Sub/Prototype/Util.pm @@ -1,5 +1,7 @@ package Sub::Prototype::Util; +use 5.006; + use strict; use warnings; @@ -12,27 +14,30 @@ Sub::Prototype::Util - Prototype-related utility routines. =head1 VERSION -Version 0.05 +Version 0.09 =cut use vars qw/$VERSION/; -$VERSION = '0.05'; +$VERSION = '0.09'; =head1 SYNOPSIS - use Sub::Prototype::Util qw/flatten recall/; + use Sub::Prototype::Util qw/flatten wrap recall/; my @a = qw/a b c/; my @args = ( \@a, 1, { d => 2 }, undef, 3 ); my @flat = flatten '\@$;$', @args; # ('a', 'b', 'c', 1, { d => 2 }) recall 'CORE::push', @args; # @a contains 'a', 'b', 'c', 1, { d => 2 }, undef, 3 + my $splice = wrap 'CORE::splice'; + my @b = $splice->(\@a, 4, 2); # @a is now ('a', 'b', 'c', 1, 3) and @b is ({ d => 2 }, undef) =head1 DESCRIPTION -Prototypes are evil, but sometimes you just have to bear with them, especially when messing with core functions. This module provides several utilities aimed at facilitating "overloading" of prototyped functions. +Prototypes are evil, but sometimes you just have to bear with them, especially when messing with core functions. +This module provides several utilities aimed at facilitating "overloading" of prototyped functions. They all handle C<5.10>'s C<_> prototype. @@ -40,123 +45,271 @@ They all handle C<5.10>'s C<_> prototype. =cut -my %sigils = qw/SCALAR $ ARRAY @ HASH % GLOB * CODE &/; +my %sigils = qw/SCALAR $ ARRAY @ HASH % GLOB * CODE &/; +my %reftypes = reverse %sigils; sub _check_ref { - my ($a, $p) = @_; - my $r; - if (!defined $a || !defined($r = reftype $a)) { # not defined or plain scalar - croak 'Got ' . ((defined $a) ? 'a plain scalar' : 'undef') - . ' where a reference was expected'; + my ($arg, $sigil) = @_; + + my $reftype; + if (not defined $arg or not defined($reftype = reftype $arg)) { + # not defined or plain scalar + my $that = (defined $arg) ? 'a plain scalar' : 'undef'; + croak "Got $that where a reference was expected"; } - croak 'Unexpected ' . $r . ' reference' unless exists $sigils{$r} - and $p =~ /\Q$sigils{$r}\E/; - return $r; + + croak "Unexpected $reftype reference" unless exists $sigils{$reftype} + and $sigil =~ /\Q$sigils{$reftype}\E/; + + $reftype; +} + +sub _clean_msg { + my ($msg) = @_; + + $msg =~ s/(?:\s+called)?\s+at\s+.*$//s; + + $msg; } =head2 C -Flattens the array C<@args> according to the prototype C<$proto>. When C<@args> is what C<@_> is after calling a subroutine with prototype C<$proto>, C returns the list of what C<@_> would have been if there were no prototype. +Flattens the array C<@args> according to the prototype C<$proto>. +When C<@args> is what C<@_> is after calling a subroutine with prototype C<$proto>, C returns the list of what C<@_> would have been if there were no prototype. +It croaks if the arguments can't possibly match the required prototype, e.g. when a reference type is wrong or when not enough elements were provided. =cut sub flatten { my $proto = shift; + return @_ unless defined $proto; - my @args; + + my @args; while ($proto =~ /(\\?)(\[[^\]]+\]|[^\];])/g) { - my $p = $2; + my $sigil = $2; + if ($1) { - my $a = shift; - my $r = _check_ref $a, $p; - my %deref = ( - SCALAR => sub { push @args, $$a }, - ARRAY => sub { push @args, @$a }, - HASH => sub { push @args, %$a }, - GLOB => sub { push @args, *$a }, - CODE => sub { push @args, &$a } - ); - $deref{$r}->(); - } elsif ($p =~ /[\@\%]/) { + my $arg = shift; + my $reftype = _check_ref $arg, $sigil; + + push @args, $reftype eq 'SCALAR' + ? $$arg + : ($reftype eq 'ARRAY' + ? @$arg + : ($reftype eq 'HASH' + ? %$arg + : ($reftype eq 'GLOB' + ? *$arg + : &$arg # _check_ref ensures this must be a code ref + ) + ) + ); + + } elsif ($sigil =~ /[\@\%]/) { push @args, @_; last; - } elsif ($p eq '_' && @_ == 0) { - push @args, $_; } else { + croak 'Not enough arguments to match this prototype' unless @_; push @args, shift; } } + return @args; } -=head2 C +=head2 C -Calls the function C<$name> with the prototyped argument list C<@args>. That is, C<@args> should be what C<@_> is when you define a subroutine with the same prototype as C<$name>. For example, +Generates a wrapper that calls the function C<$name> with a prototyped argument list. +That is, the wrapper's arguments should be what C<@_> is when you define a subroutine with the same prototype as C<$name>. - my $a = [ ]; - recall 'CORE::push', $a, 1, 2, 3; + my $a = [ 0 .. 2 ]; + my $push = wrap 'CORE::push'; + $push->($a, 3, 4); # returns 3 + 2 = 5 and $a now contains 0 .. 4 + +You can force the use of a specific prototype. +In this case, C<$name> must be a hash reference that holds exactly one key / value pair, the key being the function name and the value the prototpye that should be used to call it. + + my $push = wrap { 'CORE::push' => '\@$' }; # only pushes 1 arg + +Others arguments are seen as key / value pairs that are meant to tune the code generated by L. +Valid keys are : + +=over 4 -will call C and so fill the arrayref C<$a> with C<1, 2, 3>. This is especially needed for core functions because you can't C into them. +=item C<< ref => $func >> -You can also force the use of a specific prototype. In this case, C<$name> must be a hash reference that holds exactly one key/value pair, the key being the function name and the value the prototpye that should be used to call it. +Specifies the function used in the generated code to test the reference type of scalars. +Defaults to C<'ref'>. +You may also want to use L. - recall { 'CORE::push' => '\@$' }, $a, 1, 2, 3; # will only push 1 +=item C<< wrong_ref => $code >> -This allows you to recall into C and C by using the C<\&@> prototype : +The code executed when a reference of incorrect type is encountered. +The result of this snippet is also the result of the generated code, hence it defaults to C<'undef'>. +It's a good place to C or C too. - sub mygrep (&@) { recall { 'CORE::grep' => '\&@' }, @_ } # the prototypes are intentionally different +=item C<< sub => $bool >> + +Encloses the code into a C block. +Default is true. + +=item C<< compile => $bool >> + +Makes L compile the code generated and return the resulting code reference. +Be careful that in this case C must be a fully qualified function name. +Defaults to true, but turned off when C is false. + +=back + +For example, this allows you to recall into C and C by using the C<\&@> prototype : + + my $grep = wrap { 'CORE::grep' => '\&@' }; + sub mygrep (&@) { $grep->(@_) } # the prototypes are intentionally different =cut -sub recall { - my $name = shift; +sub _wrap { + my ($name, $proto, $i, $args, $coderefs, $opts) = @_; + + while ($proto =~ s/(\\?)(\[[^\]]+\]|[^\];])//) { + my ($ref, $sigil) = ($1, $2); + $sigil = $1 if $sigil =~ /^\[([^\]]+)\]/; + + my $cur = "\$_[$i]"; + + if ($ref) { + if (length $sigil > 1) { + my $code = "my \$r = $opts->{ref}($cur); "; + my @branches = map { + my $subcall = _wrap( + $name, $proto, ($i + 1), $args . "$_\{$cur}, ", $coderefs, $opts + ); + "if (\$r eq '$reftypes{$_}') { $subcall }"; + } split //, $sigil; + $code .= join ' els', @branches, "e { $opts->{wrong_ref} }"; + return $code; + } else { + $args .= "$sigil\{$cur}, "; + } + } elsif ($sigil =~ /[\@\%]/) { + $args .= '@_[' . $i . '..$#_]'; + } elsif ($sigil =~ /\&/) { + my %h = do { my $c; map { $_ => $c++ } @$coderefs }; + my $j; + if (exists $h{$i}) { + $j = int $h{$i}; + } else { + push @$coderefs, $i; + $j = $#{$coderefs}; + } + $args .= "sub{&{\$c[$j]}}, "; + } elsif ($sigil eq '_') { + $args .= "((\@_ > $i) ? $cur : \$_), "; + } else { + $args .= "$cur, "; + } + } continue { + ++$i; + } + + $args =~ s/,\s*$//; + + return "$name($args)"; +} + +sub _check_name { + my ($name) = @_; croak 'No subroutine specified' unless $name; + my $proto; my $r = ref $name; - if ($r eq 'HASH') { + if (!$r) { + $proto = prototype $name; + } elsif ($r eq 'HASH') { croak 'Forced prototype hash reference must contain exactly one key/value pair' unless keys %$name == 1; ($name, $proto) = %$name; - } elsif (length $r) { + } else { croak 'Unhandled ' . $r . ' reference as first argument'; } + $name =~ s/^\s+//; $name =~ s/[\s\$\@\%\*\&;].*//; - $proto = prototype $name unless $proto; - my $call = $name . '('; - my @cr; + + return $name, $proto; +} + +sub wrap { + my ($name, $proto) = _check_name shift; + croak 'Optional arguments must be passed as key => value pairs' if @_ % 2; + my %opts = @_; + + $opts{ref} ||= 'ref'; + $opts{sub} = 1 unless defined $opts{sub}; + $opts{compile} = 1 if not defined $opts{compile} and $opts{sub}; + $opts{wrong_ref} = 'undef' unless defined $opts{wrong_ref}; + + my @coderefs; + my $call; if (defined $proto) { - my $i = 0; - while ($proto =~ /(\\?)(\[[^\]]+\]|[^\];])/g) { - my $p = $2; - if ($1) { - my $r = _check_ref $_[$i], $p; - $call .= $sigils{$r} . '{$_[' . $i . ']},'; - } elsif ($p =~ /[\@\%]/) { - $call .= '@_[' . $i . '..' . (@_ - 1) . ']'; - last; - } elsif ($p =~ /\&/) { - push @cr, $_[$i]; - $call .= 'sub{&{$cr[' . $#cr . ']}},'; - } elsif ($p eq '_' && $i >= @_) { - $call .= '$_,'; - } else { - $call .= '$_[' . $i . '],'; - } - ++$i; - } - $call =~ s/,$//; + $call = _wrap $name, $proto, 0, '', \@coderefs, \%opts; } else { - $call .= join ',', map '$_[' . $_ . ']', 0 .. @_ - 1; + $call = _wrap $name, '', 0, '@_'; } - $call .= ');'; - my @ret = eval $call; - croak $@ if $@; - return @ret; + + if (@coderefs) { + my $decls = @coderefs > 1 ? 'my @c = @_[' . join(', ', @coderefs) . ']; ' + : 'my @c = ($_[' . $coderefs[0] . ']); '; + $call = $decls . $call; + } + + $call = "{ $call }"; + $call = "sub $call" if $opts{sub}; + + if ($opts{compile}) { + my $err; + { + local $@; + $call = eval $call; + $err = $@; + } + croak _clean_msg $err if $err; + } + + return $call; +} + +=head2 C + +Calls the function C<$name> with the prototyped argument list C<@args>. +That is, C<@args> should be what C<@_> is when you call a subroutine with C<$name> as prototype. +You can still force the prototype by passing C<< { $name => $proto } >> as the first argument. + + my $a = [ ]; + recall { 'CORE::push' => '\@$' }, $a, 1, 2, 3; # $a just contains 1 + +It's implemented in terms of L, and hence calls C at each run. +If you plan to recall several times, consider using L instead. + +=cut + +sub recall { + my $name = shift; + + my ($wrap, $err); + { + local $@; + $wrap = eval { wrap $name }; + $err = $@; + } + croak _clean_msg $err if $err; + + goto $wrap; } =head1 EXPORT -The functions L and L are only exported on request, either by providing their name or by the C<':funcs'> and C<':all'> tags. +The functions L, L and L are only exported on request, either by providing their name or by the C<':funcs'> and C<':all'> tags. =cut @@ -166,7 +319,7 @@ use vars qw/@EXPORT @EXPORT_OK %EXPORT_TAGS/; @EXPORT = (); %EXPORT_TAGS = ( - 'funcs' => [ qw/flatten recall/ ] + 'funcs' => [ qw/flatten wrap recall/ ] ); @EXPORT_OK = map { @$_ } values %EXPORT_TAGS; $EXPORT_TAGS{'all'} = [ @EXPORT_OK ]; @@ -179,11 +332,12 @@ L, L (core modules since perl 5), L (since 5.7.3). Vincent Pit, C<< >>, L. -You can contact me by mail or on #perl @ FreeNode (vincent or Prof_Vince). +You can contact me by mail or on C (vincent). =head1 BUGS -Please report any bugs or feature requests to C, or through the web interface at L. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. +Please report any bugs or feature requests to C, or through the web interface at L. +I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. =head1 SUPPORT @@ -195,7 +349,7 @@ Tests code coverage report is available at L