X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FPrototype%2FUtil.pm;h=78182d395962fe7ee4b60a83baedf005464ee1fa;hb=812065270f1262b670f91bc7de80f67c583a123e;hp=661d03d71cb1354f1c13f28a15f6e08c71fa2e37;hpb=5e934b02978f8e2a411e8aba352fc6465c0e3aba;p=perl%2Fmodules%2FSub-Prototype-Util.git

diff --git a/lib/Sub/Prototype/Util.pm b/lib/Sub/Prototype/Util.pm
index 661d03d..78182d3 100644
--- a/lib/Sub/Prototype/Util.pm
+++ b/lib/Sub/Prototype/Util.pm
@@ -12,11 +12,13 @@ Sub::Prototype::Util - Prototype-related utility routines.
 
 =head1 VERSION
 
-Version 0.02
+Version 0.06
 
 =cut
 
-our $VERSION = '0.02';
+use vars qw/$VERSION/;
+
+$VERSION = '0.06';
 
 =head1 SYNOPSIS
 
@@ -39,6 +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, $p) = @_;
@@ -78,7 +81,7 @@ sub flatten {
   } elsif ($p =~ /[\@\%]/) {
    push @args, @_;
    last;
-  } elsif ($p eq '_') {
+  } elsif ($p eq '_' && @_ == 0) {
    push @args, $_;
   } else {
    push @args, shift;
@@ -96,55 +99,184 @@ Calls the function C<$name> with the prototyped argument list C<@args>. That is,
 
 will call C<push @$a, 1, 2, 3> and so fill the arrayref C<$a> with C<1, 2, 3>. This is especially needed for core functions because you can't C<goto> into them.
 
+You can also force the use of a specific prototype. In this case, C<$name> must be a hash reference that holds exactly one key/value pair, the key being the function name and the value the prototpye that should be used to call it.
+
+    recall { 'CORE::push' => '\@$' }, $a, 1, 2, 3; # will only push 1
+
+This allows you to recall into C<CORE::grep> and C<CORE::map> by using the C<\&@> prototype :
+
+    sub mygrep (&@) { recall { 'CORE::grep' => '\&@' }, @_ } # the prototypes are intentionally different
+
 =cut
 
-sub recall {
- my ($name, @a) = @_;
- croak 'Wrong subroutine name' unless $name;
+sub _check_name {
+ my $name = $_[0];
+ croak 'No subroutine specified' unless $name;
+ my $proto;
+ my $r = ref $name;
+ if ($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) {
+  croak 'Unhandled ' . $r . ' reference as first argument';
+ }
  $name =~ s/^\s+//;
  $name =~ s/[\s\$\@\%\*\&;].*//;
- my $proto = prototype $name;
- my @args;
+ $proto = prototype $name unless $proto;
+ return $name, $proto;
+}
+
+sub recall {
+ my ($name, $proto) = _check_name shift;
+ my $call = $name . '(';
+ my @cr;
  if (defined $proto) {
   my $i = 0;
   while ($proto =~ /(\\?)(\[[^\]]+\]|[^\];])/g) {
    my $p = $2;
    if ($1) {
-    my $r = _check_ref $a[$i], $p;
-    push @args, join '', $sigils{$r}, '{$a[', $i, ']}';
+    my $r = _check_ref $_[$i], $p;
+    $call .= $sigils{$r} . '{$_[' . $i . ']},';
    } elsif ($p =~ /[\@\%]/) {
-    push @args, join '', '@a[', $i, '..', (@a - 1), ']';
+    $call .= '@_[' . $i . '..' . (@_ - 1) . ']';
     last;
    } elsif ($p =~ /\&/) {
-    push @args, 'sub{&{$a[' . $i . ']}}';
-   } elsif ($p eq '_') {
-    push @args, '$_';
+    push @cr, $_[$i];
+    $call .= 'sub{&{$cr[' . $#cr . ']}},';
+   } elsif ($p eq '_' && $i >= @_) {
+    $call .= '$_,';
    } else {
-    push @args, '$a[' . $i . ']';
+    $call .= '$_[' . $i . '],';
    }
    ++$i; 
   }
+  $call =~ s/,$//;
  } else {
-  @args = map '$a[' . $_ . ']', 0 .. @a - 1;
+  $call .= join ',', map '$_[' . $_ . ']', 0 .. @_ - 1;
  }
- my @ret = eval $name . '(' . join(',', @args) . ');';
+ $call .= ');';
+ my @ret = eval $call;
  croak $@ if $@;
  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
 
 use base qw/Exporter/;
 
-our @EXPORT         = ();
-our %EXPORT_TAGS    = (
- 'funcs' =>  [ qw/flatten recall/ ]
+use vars qw/@EXPORT @EXPORT_OK %EXPORT_TAGS/;
+
+@EXPORT             = ();
+%EXPORT_TAGS        = (
+ 'funcs' =>  [ qw/flatten recall wrap/ ]
 );
-our @EXPORT_OK      = map { @$_ } values %EXPORT_TAGS;
+@EXPORT_OK          = map { @$_ } values %EXPORT_TAGS;
 $EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
 
 =head1 DEPENDENCIES