Importing Sub-Prototype-Util-0.06.tar.gz

[perl/modules/Sub-Prototype-Util.git] / lib / Sub / Prototype / Util.pm

diff --git a/lib/Sub/Prototype/Util.pm b/lib/Sub/Prototype/Util.pm
index 73a1a60115f6d384ace73083584543d99bf60cc0..78182d395962fe7ee4b60a83baedf005464ee1fa 100644 (file)
--- a/lib/Sub/Prototype/Util.pm
+++ b/lib/Sub/Prototype/Util.pm
@@ -12,13 +12,13 @@ Sub::Prototype::Util - Prototype-related utility routines.
 
 =head1 VERSION
 
-Version 0.05
+Version 0.06
 
 =cut
 
 use vars qw/$VERSION/;
 
-$VERSION = '0.05';
+$VERSION = '0.06';
 
 =head1 SYNOPSIS
 
@@ -41,6 +41,7 @@ They all handle C<5.10>'s C<_> prototype.
 =cut
 
 my %sigils = qw/SCALAR $ ARRAY @ HASH % GLOB * CODE &/;
+my %reftypes = reverse %sigils;
 
 sub _check_ref {
  my ($a, $p) = @_;
@@ -108,8 +109,8 @@ This allows you to recall into C<CORE::grep> and C<CORE::map> by using the C<\&@
 
 =cut
 
-sub recall {
- my $name = shift;
+sub _check_name {
+ my $name = $_[0];
  croak 'No subroutine specified' unless $name;
  my $proto;
  my $r = ref $name;
@@ -122,6 +123,11 @@ sub recall {
  $name =~ s/^\s+//;
  $name =~ s/[\s\$\@\%\*\&;].*//;
  $proto = prototype $name unless $proto;
+ return $name, $proto;
+}
+
+sub recall {
+ my ($name, $proto) = _check_name shift;
  my $call = $name . '(';
  my @cr;
  if (defined $proto) {
@@ -154,9 +160,111 @@ sub recall {
  return @ret;
 }
 
+=head2 C<wrap $name, %opts>
+
+Generates a wrapper that does the same thing as L</recall>, but specialized for a given function. This wrapper can be compiled once for all to avoid calling C<eval> at each run (like L</recall> does). You can still force the prototype by passing C<< { $name => $proto } >> as the first argument. Others arguments are seen as key / value pairs and tune the code generated by L</wrap>. Valid keys are :
+
+=over 4
+
+=item C<< ref => $func >>
+
+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 C<Scalar::Util::reftype>.
+
+=item C<< wrong_ref => $code >>
+
+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<croak> or C<die> too.
+
+=item C<< sub => $bool >>
+
+Encloses the code into a C<sub { }> block. Default is true.
+
+=item C<< compile => $bool >>
+
+Makes L</wrap> compile the code generated and return the resulting code reference. Implies C<< sub => 1 >>. Be careful that in this case C<ref> must be a fully qualified function name. Defaults to false.
+
+=back
+
+This is how you make your own C<push> that pushes into array references :
+
+    my @a = (0 .. 2);
+    my $push = wrap 'CORE::push', compile => 1;
+    $push->(\@a, 3 .. 7); # returns 3 + 5 = 8, and @a now contains 0 .. 7
+
+=cut
+
+sub _wrap {
+ my ($name, $proto, $i, $args, $cr, $opts) = @_;
+ if ($proto =~ /(\\?)(\[[^\]]+\]|[^\];])(.*)/g) {
+  my ($ref, $p) = ($1, $2);
+  $proto = $3;
+  $p = $1 if $p =~ /^\[([^\]]+)\]/;
+  if ($ref) {
+   if (length $p > 1) {
+    return 'my $r = ' . $opts->{ref} . '($_[' . $i . ']); ' 
+           . join ' els',
+              map( {
+               "if (\$r eq '" . $reftypes{$_} ."') { "
+               . _wrap($name, $proto, ($i + 1),
+                              $args . $_ . '{$_[' . $i . ']}, ',
+                              $cr, $opts)
+               . ' }'
+              } split //, $p),
+              'e { ' . $opts->{wrong_ref} . ' }'
+   } else {
+    $args .= $p . '{$_[' . $i . ']}, ';
+   }
+  } elsif ($p =~ /[\@\%]/) {
+   $args .= '@_[' . $i . '..$#_]';
+  } elsif ($p =~ /\&/) {
+   my %h = do { my $c; map { $_ => $c++ } @$cr };
+   my $j;
+   if (not exists $h{$i}) {
+    push @$cr, $i;
+    $j = $#{$cr};
+   } else {
+    $j = int $h{$i};
+   }
+   $args .= 'sub{&{$c[' . $j . ']}}, ';
+  } elsif ($p eq '_') {
+   $args .= '((@_ > ' . $i . ') ? $_[' . $i . '] : $_), ';
+  } else {
+   $args .= '$_[' . $i . '], ';
+  }
+  return _wrap($name, $proto, ($i + 1), $args, $cr, $opts);
+ } else {
+  $args =~ s/,\s*$//;
+  return $name . '(' . $args . ')';
+ }
+}
+
+sub wrap {
+ my ($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       if not exists $opts{sub} or $opts{compile};
+ $opts{wrong_ref} = 'undef' if not defined $opts{wrong_ref};
+ my @cr;
+ my $call;
+ if (defined $proto) {
+  $call = _wrap $name, $proto, 0, '', \@cr, \%opts;
+ } else {
+  $call = _wrap $name, '', 0, '@_';
+ }
+ if (@cr) {
+  $call = 'my @c; '
+        . join('', map { 'push @c, $_[' . $_ . ']; ' } @cr)
+        . $call
+ }
+ $call = '{ ' . $call . ' }';
+ $call = 'sub ' . $call if $opts{sub};
+ $call = eval $call     if $opts{compile};
+ return $call;
+}
+
 =head1 EXPORT
 
-The functions L</flatten> and L</recall> are only exported on request, either by providing their name or by the C<':funcs'> and C<':all'> tags.
+The functions L</flatten>, L</recall> and L</wrap> are only exported on request, either by providing their name or by the C<':funcs'> and C<':all'> tags.
 
 =cut
 
@@ -166,7 +274,7 @@ use vars qw/@EXPORT @EXPORT_OK %EXPORT_TAGS/;
 
 @EXPORT             = ();
 %EXPORT_TAGS        = (
- 'funcs' =>  [ qw/flatten recall/ ]
+ 'funcs' =>  [ qw/flatten recall wrap/ ]
 );
 @EXPORT_OK          = map { @$_ } values %EXPORT_TAGS;
 $EXPORT_TAGS{'all'} = [ @EXPORT_OK ];