X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FNary.pm;h=313381f435686db10599dac7f30b7e621e031be3;hb=2eb7d799fbc08f3dbeada52aeac89c781983e081;hp=7fe085855580aa53a478126802822797cf65a063;hpb=b88f2c41d644a13f58e593d23bdf8525632a45f1;p=perl%2Fmodules%2FSub-Nary.git

diff --git a/lib/Sub/Nary.pm b/lib/Sub/Nary.pm
index 7fe0858..313381f 100644
--- a/lib/Sub/Nary.pm
+++ b/lib/Sub/Nary.pm
@@ -43,9 +43,23 @@ The usual constructor. Currently takes no argument.
 
 =head2 C<nary $coderef>
 
-Takes a code reference to a named or anonymous subroutine, and returns a hash reference whose keys are the possible numbers of returning scalars, and the corresponding values the "probability" to get them. The special key C<'list'> is used to denote a possibly infinite number of returned arguments. The return value hence would look at
+Takes a code reference to a named or anonymous subroutine, and returns a hash reference whose keys are the possible numbers of returning scalars, and the corresponding values the "probability" to get them. A few special keys are also used :
 
-    { 1 => 0.2, 2 => 0.4, 4 => 0.3, list => 0.1 }
+=over 4
+
+=item *
+
+C<'list'> is used to denote a possibly infinite number of returned arguments ;
+
+=item *
+
+C<'exit'> gives the probability for C<exit> to be called somewhere in the code.
+
+=back
+
+The return value hence would look at
+
+    { 1 => 0.2, 2 => 0.4, 4 => 0.25, list => 0.1, exit => 0.05 }
 
 that is, we should get C<1> scalar C<1> time over C<5> and so on. The sum of all values is C<1>. The returned result, and all the results obtained from intermediate subs, are cached into the object.
 
@@ -59,7 +73,9 @@ The probability is computed as such :
 
 =over 4
 
-=item * When branching, each branch is considered equally possible.
+=item *
+
+When branching, each branch is considered equally possible.
 
 For example, the subroutine
 
@@ -85,7 +101,9 @@ As for
 
 it is considered to return C<3> scalars with probability C<1/2>, C<2> with probability C<1/2 * 1/2 = 1/4> and C<1> (when the two tests fail, the last computed value is returned, which here is C<< $x > 0.9 >> evaluated in the scalar context of the test) with remaining probability C<1/4>.
 
-=item * The total probability law for a given returning point is the convolution product of the probabilities of its list elements.
+=item *
+
+The total probability law for a given returning point is the convolution product of the probabilities of its list elements.
 
 As such, 
 
@@ -101,13 +119,17 @@ 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.
+=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.
+=item *
 
-This is just a pedantic way to say that "list + fixed length = list".
+The C<list> and C<exit> states are absorbing in regard of all the other ones.
+
+This is just a pedantic way to say that C<list + fixed length = list>, C<exit + fixed length = exit>, but note also that C<exit + list = exit>.
 That's why
 
     sub listy {
@@ -116,7 +138,7 @@ That's why
 
 is considered as always returning an unbounded list.
 
-Also, the convolution law does not behave the same when C<list> elements are involved : in the following example,
+Also, the convolution law does not behave the same when C<list> or C<exit> elements are involved : in the following example,
 
     sub oneorlist {
      if (rand < 0.1) {
@@ -191,7 +213,7 @@ sub power {
 my %ops;
 
 $ops{$_} = 1      for scalops;
-$ops{$_} = 0      for qw/stub nextstate pushmark iter unstack/;
+$ops{$_} = 0      for qw/stub nextstate iter unstack/;
 $ops{$_} = 1      for qw/padsv/;
 $ops{$_} = 'list' for qw/padav/;
 $ops{$_} = 'list' for qw/padhv rv2hv/;
@@ -212,11 +234,33 @@ $ops{$_} = { 0 => 0.5, 4 => 0.5 }  for qw/gnbyname gnbyaddr gnetent/;
 $ops{$_} = { 0 => 0.5, 3 => 0.5 }  for qw/gpbyname gpbynumber gprotoent/;
 $ops{$_} = { 0 => 0.5, 4 => 0.5 }  for qw/gsbyname gsbyport gservent/;
 
+# Stolen from B::Deparse
+
+sub padval { $_[0]->{cv}->[0]->PADLIST->ARRAYelt(1)->ARRAYelt($_[1]) }
+
+sub gv_or_padgv {
+ my ($self, $op) = @_;
+ if (class($op) eq 'PADOP') {
+  return $self->padval($op->padix)
+ } else { # class($op) eq "SVOP"
+  return $op->gv;
+ }
+}
+
+sub const_sv {
+ my ($self, $op) = @_;
+ my $sv = $op->sv;
+ # the constant could be in the pad (under useithreads)
+ $sv = $self->padval($op->targ) unless $$sv;
+ return $sv;
+}
+
 sub enter {
  my ($self, $cv) = @_;
 
  return undef, 'list' if class($cv) ne 'CV';
  my $op  = $cv->ROOT;
+ return undef, 'list' if null $op;
  my $tag = tag($op);
 
  return undef, { %{$self->{cache}->{$tag}} } if exists $self->{cache}->{$tag};
@@ -234,54 +278,91 @@ sub enter {
  return undef, $r;
 }
 
+use Test::More;
+use Data::Dumper;
+
 sub inspect {
  my ($self, $op) = @_;
 
  my $n = name($op);
- return add($self->inspect_kids($op)), undef if $n eq 'return';
-
  my $meth = $self->can('pp_' . $n);
  return $self->$meth($op) if $meth;
 
+ my $l;
  if (exists $ops{$n}) {
-  my $l = $ops{$n};
+  $l = $ops{$n};
   $l = { %$l } if ref $l;
-  return undef, $l;
  }
 
- if (class($op) eq 'LOGOP' and not null $op->first) {
-  my @res;
+ my $c = class($op);
+ $meth = $self->can('OPc_' . $c);
+ if ($meth) {
+  my ($r, $lc) = $self->$meth($op);
+  $lc = $l if defined $l;
+  return $r, $lc;
+ }
 
-  my $op = $op->first;
-  my ($r1, $l1) = $self->inspect($op);
-  return $r1, $l1 if defined $r1 and zero $l1;
-  my $c = count $l1;
+ return undef, (defined $l) ? $l : 0;
+}
 
-  $op = $op->sibling;
-  my ($r2, $l2) = $self->inspect($op);
+# UNOPs
 
-  $op = $op->sibling;
-  my ($r3, $l3);
-  if (null $op) {
-   # If the logop has no else branch, it can also return the *scalar* result of
-   # the conditional
-   $l3 = { 1 => 1 };
-  } else {
-   ($r3, $l3) = $self->inspect($op);
-  }
+sub OPc_UNOP { $_[0]->inspect($_[1]->first); }
 
-  my $r = add $r1, scale $c / 2, add $r2, $r3;
-  my $l = scale $c / 2, add $l2, $l3;
-  return $r, $l
- }
+# BINOPs
+
+sub OPc_BINOP {
+ my ($self, $op) = @_;
+
+ my ($r, $l1) = $self->inspect($op->first);
+ return $r, $l1 unless defined $l1;
 
- return $self->inspect_kids($op);
+ my ($r2, $l2) = $self->inspect($op->last);
+ my $c = 1 - count $r;
+ $r = add $r, scale $c, $r2 if defined $r2;
+
+ my $l = scale +(1 - count $r), normalize combine $l1, $l2;
+
+ return $r, $l;
 }
 
-sub inspect_kids {
+# LOGOPs
+
+sub OPc_LOGOP {
  my ($self, $op) = @_;
+ my @res;
+
+ $op = $op->first;
+ return undef, 0 if null $op;
 
- return undef, 0 unless $op->flags & OPf_KIDS;
+ my ($r1, $l1) = $self->inspect($op);
+ return $r1, $l1 if defined $r1 and zero $l1;
+ my $c = count $l1;
+
+ $op = $op->sibling;
+ my ($r2, $l2) = $self->inspect($op);
+
+ $op = $op->sibling;
+ my ($r3, $l3);
+ if (null $op) {
+  # If the logop has no else branch, it can also return the *scalar* result of
+  # the conditional
+  $l3 = { 1 => 1 };
+ } else {
+  ($r3, $l3) = $self->inspect($op);
+ }
+
+ my $r = add $r1, scale $c / 2, add $r2, $r3;
+ my $l = scale $c / 2, add $l2, $l3;
+ return $r, $l;
+
+ return $self->OPc_LISTOP($op);
+}
+
+# LISTOPs
+
+sub OPc_LISTOP {
+ my ($self, $op) = @_;
 
  $op = $op->first;
  return undef, 0 if null $op;
@@ -318,36 +399,15 @@ sub inspect_kids {
  return $r, $l;
 }
 
-# Stolen from B::Deparse
-
-sub padval { $_[0]->{cv}->[0]->PADLIST->ARRAYelt(1)->ARRAYelt($_[1]) }
-
-sub gv_or_padgv {
- my ($self, $op) = @_;
- if (class($op) eq 'PADOP') {
-  return $self->padval($op->padix)
- } else { # class($op) eq "SVOP"
-  return $op->gv;
- }
-}
-
-sub const_sv {
- my ($self, $op) = @_;
- my $sv = $op->sv;
- # the constant could be in the pad (under useithreads)
- $sv = $self->padval($op->targ) unless $$sv;
- return $sv;
-}
+sub pp_return { add($_[0]->OPc_LISTOP($_[1])), undef }
 
 sub pp_entersub {
  my ($self, $op) = @_;
 
  $op = $op->first while $op->flags & OPf_KIDS;
- return undef, 0 if null $op;
- if (name($op) eq 'pushmark') {
-  $op = $op->sibling;
-  return undef, 0 if null $op;
- }
+ # First must be a pushmark
+ $op = $op->sibling;
+ # Next must be non null - at worse it's the rv2cv
 
  my $r;
  my $c = 1;
@@ -368,8 +428,8 @@ sub pp_entersub {
     $next = $next->sibling;
    }
    $n  = name($op)
-  } while ($op->flags & OPf_KIDS and { map { $_ => 1 } qw/null leave/ }->{$n});
-  return 'list', undef unless { map { $_ => 1 } qw/gv refgen/ }->{$n};
+  } while $op->flags & OPf_KIDS and ($n eq 'null' or $n eq 'leave');
+  return 'list', undef unless $n eq 'gv' or $n eq 'refgen';
   local $self->{sub} = 1;
   my ($rc, $lc) = $self->inspect($op);
   return $r, scale $c, $lc;
@@ -391,6 +451,35 @@ sub pp_anoncode {
  return $self->{sub} ? $self->enter($self->const_sv($op)) : (undef, 1)
 }
 
+sub pp_exit {
+ my ($self, $op) = @_;
+
+ my $r;
+ if ($op->flags & OPf_KIDS) {
+  ($r, my $l) = $self->inspect($op->first);
+  return $r, $l if defined $r and zero $l;
+  $r->{exit} = 1 - count $r;
+ } else {
+  $r = { 'exit' => 1 };
+ }
+
+ return $r, undef;
+}
+
+sub pp_die {
+ my ($self, $op) = @_;
+
+ my ($r, undef) = $self->OPc_LISTOP($op);
+ if (defined $r) {
+  my $c = 1 - count $r;
+  $r->{die} = $c if $c;
+ } else {
+  $r = { die => 1 };
+ }
+
+ return $r, undef;
+}
+
 sub pp_goto {
  my ($self, $op) = @_;
 
@@ -456,6 +545,8 @@ sub pp_sassign {
  return $r, $c ? { 1 => $c } : undef
 }
 
+=cut
+
 sub pp_aassign {
  my ($self, $op) = @_;
 
@@ -468,6 +559,27 @@ sub pp_aassign {
  $self->inspect($op);
 }
 
+=cut
+
+sub pp_leavetry {
+ my ($self, $op) = @_;
+
+ my ($r, $l) = $self->OPc_LISTOP($op);
+ if (defined $r) {
+  my $d = delete $r->{die};
+  return $r, $l if not defined $d;
+  if (defined $l) {
+   my $z = delete $l->{0};
+   $l = { %$l, 0 => $z };
+   $l->{0} += $d;
+  } else {
+   $l = { 0 => $d };
+  }
+ }
+
+ return $r, $l;
+}
+
 sub pp_leaveloop {
  my ($self, $op) = @_;
 
@@ -600,7 +712,7 @@ L<Carp> (standard since perl 5), L<B> (since perl 5.005) and L<XSLoader> (since
 
 Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
 
-You can contact me by mail or on #perl @ FreeNode (vincent or Prof_Vince).
+You can contact me by mail or on C<irc.perl.org> (vincent).
 
 =head1 BUGS