X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FNary.pm;h=058048249bb723f9a23481098addd389b342615e;hb=04997f51e7b0a73e04ef0c8df41d4ad045fc7584;hp=427ee8c7eb7cfe3b021d58ae0887117bd1523bfc;hpb=cab48037c2f684dd60d1860bdc2efa3d10d3e7a3;p=perl%2Fmodules%2FSub-Nary.git

diff --git a/lib/Sub/Nary.pm b/lib/Sub/Nary.pm
index 427ee8c..0580482 100644
--- a/lib/Sub/Nary.pm
+++ b/lib/Sub/Nary.pm
@@ -16,13 +16,13 @@ Sub::Nary - Try to count how many elements a subroutine can return in list conte
 
 =head1 VERSION
 
-Version 0.01
+Version 0.02
 
 =cut
 
 our $VERSION;
 BEGIN {
- $VERSION  = '0.01';
+ $VERSION  = '0.02';
 }
 
 =head1 SYNOPSIS
@@ -102,6 +102,10 @@ returns C<3> or C<4> arguments with probability C<1/2> ; and
 
 never returns C<1> argument but returns C<2> with probability C<1/2 * 1/2 = 1/4>, C<3> with probability C<1/2 * 1/2 + 1/2 * 1/2 = 1/2> and C<4> with probability C<1/4> too.
 
+=item * If a core function may return different numbers of scalars, each kind is considered equally possible.
+
+For example, C<stat> returns C<13> elements on success and C<0> on error. The according probability will then be C<< { 0 => 0.5, 13 => 0.5 } >>.
+
 =item * The C<list> state is absorbing in regard of all the other ones.
 
 This is just a pedantic way to say that "list + fixed length = list".
@@ -190,6 +194,21 @@ sub combine {
  }} map { (ref) ? $_ : { $_ => 1 } } grep defined, @_;
 }
 
+sub power {
+ my ($p, $n, $c) = @_;
+ my $s = sum values %$p;
+ return { 0 => $s * $c } unless $n;
+ if ($n eq 'list') {
+  my $z = delete $p->{0};
+  return { 'list' => $c } unless $z;
+  return { 0      => $c } if $z == 1;
+  return { 0 => $c * $z, list => $c * ($s - $z) };
+ }
+ my $r = combine map { { %$p } } 1 .. $n;
+ $r->{$_} *= $c for keys %$r;
+ return $r;
+}
+
 sub add {
  reduce {
   $a->{$_} += $b->{$_} for keys %$b;
@@ -204,7 +223,8 @@ $ops{$_} = 0      for qw/stub nextstate/;
 $ops{$_} = 1      for qw/padsv/;
 $ops{$_} = 'list' for qw/padav/;
 $ops{$_} = 'list' for qw/padhv rv2hv/;
-$ops{$_} = 'list' for qw/padany match entereval readline/;
+$ops{$_} = 'list' for qw/padany/;
+$ops{$_} = 'list' for qw/match entereval readline/;
 
 $ops{each}      = { 0 => 0.5, 2 => 0.5 };
 $ops{stat}      = { 0 => 0.5, 13 => 0.5 };
@@ -248,7 +268,7 @@ sub enter {
 sub expect_return {
  my ($self, $op) = @_;
 
- return ($self->expect_list($op))[0] => 1 if name($op) eq 'return';
+ return ($self->expect_kids($op))[0] => 1 if name($op) eq 'return';
 
  if ($op->flags & OPf_KIDS) {
   for ($op = $op->first; not null $op; $op = $op->sibling) {
@@ -257,48 +277,24 @@ sub expect_return {
   }
  }
 
- return;
+ return 0;
 }
 
-sub expect_list {
+sub expect_any {
  my ($self, $op) = @_;
 
  my $n = name($op);
+ return ($self->expect_kids($op))[0] => 1 if $n eq 'return';
+
  my $meth = $self->can('pp_' . $n);
  return $self->$meth($op) if $meth;
+
  if (exists $ops{$n}) {
   my $r = $ops{$n};
-  $r = { %$r } if ref $r eq 'HASH';
+  $r = { %$r } if ref $r;
   return $r => 0;
  }
 
- if ($op->flags & OPf_KIDS) {
-  my @res = (0);
-  my ($p, $r);
-  for ($op = $op->first; not null $op; $op = $op->sibling) {
-   my $n = name($op);
-   next if $n eq 'pushmark';
-   if ($n eq 'nextstate'
-       and not null(($op = $op->sibling)->sibling)) {
-    ($p, $r) = $self->expect_return($op);
-    return $p => 1 if $r;
-   } else {
-    ($p, $r) = $self->expect_any($op);
-    return $p => 1 if $r;
-    push @res, $p;
-   }
-  }
-  return (combine @res) => 0;
- }
-
- return;
-}
-
-sub expect_any {
- my ($self, $op) = @_;
-
- return ($self->expect_list($op))[0] => 1 if name($op) eq 'return';
-
  if (class($op) eq 'LOGOP' and not null $op->first) {
   my @res;
   my ($p, $r);
@@ -322,7 +318,31 @@ sub expect_any {
   return (add @res) => 0;
  }
 
- return $self->expect_list($op);
+ return $self->expect_kids($op);
+}
+
+sub expect_kids {
+ my ($self, $op) = @_;
+
+ return 0 unless $op->flags & OPf_KIDS;
+
+ my @res = (0);
+ my ($p, $r);
+ for ($op = $op->first; not null $op; $op = $op->sibling) {
+  my $n = name($op);
+  next if $n eq 'pushmark';
+  if ($n eq 'nextstate'
+      and not null(($op = $op->sibling)->sibling)) {
+   ($p, $r) = $self->expect_return($op);
+   return $p => 1 if $r;
+  } else {
+   ($p, $r) = $self->expect_any($op);
+   return $p => 1 if $r;
+   push @res, $p;
+  }
+ }
+
+ return (combine @res) => 0;
 }
 
 # Stolen from B::Deparse
@@ -416,13 +436,12 @@ sub pp_goto {
 sub pp_const {
  my ($self, $op) = @_;
 
- if (class($op) eq 'SVOP' and (my $sv = $self->const_sv($op))) {
-  my $c = class($sv);
-  if ($c eq 'AV') {
-   return $sv->FILL + 1;
-  } elsif ($c eq 'HV') {
-   return 2 * $sv->FILL;
-  }
+ my $sv = $self->const_sv($op);
+ my $c = class($sv);
+ if ($c eq 'AV') {
+  return $sv->FILL + 1;
+ } elsif ($c eq 'HV') {
+  return 2 * $sv->FILL;
  }
 
  return 1;
@@ -442,7 +461,17 @@ sub pp_rv2av {
  return (name($op) eq 'const') ? $self->expect_any($op) : 'list';
 }
 
-sub pp_aassign { $_[0]->expect_any($_[1]->first) }
+sub pp_aassign {
+ my ($self, $op) = @_;
+
+ $op = $op->first;
+
+ # Can't assign to return
+ my ($p, $r) = $self->expect_any($op->sibling);
+ return $p => 0 if not exists $p->{list};
+
+ $self->expect_any($op);
+}
 
 sub pp_leaveloop { $_[0]->expect_return($_[1]->first->sibling) }
 
@@ -472,6 +501,41 @@ sub pp_flip {
  return 'list'
 }
 
+sub pp_grepwhile {
+ my ($self, $op) = @_;
+
+ $op = $op->first;
+ return 'list' if name($op) ne 'grepstart';
+
+ $op = $op->first->sibling;
+ my ($p, $r) = $self->expect_any($op);
+ return $p => 1 if $r;
+
+ $op = $op->sibling;
+ ($p, $r) = $self->expect_any($op);
+ return $p => 1 if $r;
+
+ return 'list';
+}
+
+sub pp_mapwhile {
+ my ($self, $op) = @_;
+
+ $op = $op->first;
+ return 'list' if name($op) ne 'mapstart';
+
+ $op = $op->first->sibling;
+ my ($p1, $r) = $self->expect_any($op);
+ return $p1 => 1 if $r;
+
+ $op = $op->sibling;
+ (my $p2, $r) = $self->expect_any($op);
+ return $p2 => 1 if $r;
+ $p2 = { $p2 => 1 } unless ref $p2;
+
+ return add map { power $p1, $_, $p2->{$_} } keys %$p2;
+}
+
 =head1 EXPORT
 
 An object-oriented module shouldn't export any function, and so does this one.