X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FNary.pm;h=f3f87e300cc901c220c6f7cad5319ff20617c2cc;hb=9c114b45769d6880b8635884bb3734f00c2742c2;hp=8af7cd6671c8662ca7e09e3ea02fb6933ab9a814;hpb=a1d67c5f3a8c72b0d81d6e6c2aaee64921930491;p=perl%2Fmodules%2FSub-Nary.git diff --git a/lib/Sub/Nary.pm b/lib/Sub/Nary.pm index 8af7cd6..f3f87e3 100644 --- a/lib/Sub/Nary.pm +++ b/lib/Sub/Nary.pm @@ -9,25 +9,21 @@ use Carp qw/croak/; use B qw/class ppname svref_2object OPf_KIDS/; -use Test::More; use Data::Dumper; - =head1 NAME Sub::Nary - Try to count how many elements a subroutine can return in list context. =head1 VERSION -Version 0.02 +Version 0.03 =cut our $VERSION; BEGIN { - $VERSION = '0.02'; + $VERSION = '0.03'; } -our $DEBUG = 0; - =head1 SYNOPSIS use Sub::Nary; @@ -63,7 +59,9 @@ 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 @@ -89,7 +87,9 @@ 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, @@ -105,11 +105,15 @@ 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 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 state is absorbing in regard of all the other ones. +=item * + +The C state is absorbing in regard of all the other ones. This is just a pedantic way to say that "list + fixed length = list". That's why @@ -234,7 +238,6 @@ sub enter { my $r = add $self->inspect($op->first); shift @{$self->{cv}}; - $r = { $r => 1 } unless ref $r; $self->{cache}->{$tag} = { %$r }; return undef, $r; } @@ -243,7 +246,6 @@ sub inspect { my ($self, $op) = @_; my $n = name($op); - diag "@ $n" if $DEBUG; return add($self->inspect_kids($op)), undef if $n eq 'return'; my $meth = $self->can('pp_' . $n); @@ -258,11 +260,9 @@ sub inspect { if (class($op) eq 'LOGOP' and not null $op->first) { my @res; - diag "? logop\n" if $DEBUG; - my $op = $op->first; my ($r1, $l1) = $self->inspect($op); - return $r1, $l1 if $r1 and zero $l1; + return $r1, $l1 if defined $r1 and zero $l1; my $c = count $l1; $op = $op->sibling; @@ -311,10 +311,8 @@ sub inspect_kids { $op = $op->first; redo; } - diag "> $n" if $DEBUG; my ($rc, $lc) = $self->inspect($op); $c = 1 - count $r; - diag Dumper [ $c, $r, \@l, $rc, $lc ] if $DEBUG; $r = add $r, scale $c, $rc if defined $rc; if (not defined $lc) { @l = (); @@ -323,7 +321,6 @@ sub inspect_kids { push @l, scale $c, $lc; } -# diag Dumper \@l if $DEBUG; my $l = scale +(1 - count $r), normalize combine @l; return $r, $l; @@ -354,24 +351,16 @@ sub pp_entersub { my ($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; for (; not null $op->sibling; $op = $op->sibling) { - my $n = name($op); - next if $n eq 'nextstate'; - diag "* $n" if $DEBUG; my ($rc, $lc) = $self->inspect($op); - $r = add $r, scale $c, $rc if defined $rc; - if (zero $lc) { - $c = 1 - count $r; - return $r, $c ? { 0 => $c } : undef - } + return $rc, $lc if defined $rc and not defined $lc; + $r = add $r, scale $c, $rc; $c *= count $lc; } @@ -457,12 +446,20 @@ sub pp_rv2av { my ($self, $op) = @_; $op = $op->first; - my ($r, $l) = $self->inspect($op); - if (name($op) ne 'const') { - my $c = 1 - count $r; - $l = $c ? { list => $c } : 0; + if (name($op) eq 'gv') { + return undef, { list => 1 }; } - return $r, $l; + + $self->inspect($op); +} + +sub pp_sassign { + my ($self, $op) = @_; + + my $r = ($self->inspect($op->first))[0]; + + my $c = 1 - count $r; + return $r, $c ? { 1 => $c } : undef } sub pp_aassign { @@ -480,27 +477,33 @@ sub pp_aassign { sub pp_leaveloop { my ($self, $op) = @_; - diag "* leaveloop" if $DEBUG; - $op = $op->first; my ($r1, $l1); - if (name($op) eq 'enteriter') { + my $for; + if (name($op) eq 'enteriter') { # for loop ? + $for = 1; ($r1, $l1) = $self->inspect($op); - return $r1, $l1 if $r1 and zero $l1; + return $r1, $l1 if defined $r1 and zero $l1; } $op = $op->sibling; - my $r; + my ($r2, $l2); if (name($op->first) eq 'and') { - ($r, my $l) = ($self->inspect($op->first->first))[0]; - return $r, $l if $r and zero $l; - $r = ($self->inspect($op->first->first->sibling))[0]; + ($r2, $l2) = $self->inspect($op->first->first); + return $r2, $l2 if defined $r2 and zero $l2; + my $c = count $l2; + return { list => 1 }, undef if !$for and defined $r2; + my ($r3, $l3) = $self->inspect($op->first->first->sibling); + return { list => 1 }, undef if defined $r3 and defined $l3; + $r2 = add $r2, scale $c, $r3; } else { - $r = ($self->inspect($op))[0]; + ($r2, $l2) = $self->inspect($op); + return { list => 1 }, undef if defined $r2 and defined $l2; } + my $r = (defined $r1) ? add $r1, scale +(1 - count $r1), $r2 + : $r2; my $c = 1 - count $r; - diag "& leaveloop $c" if $DEBUG; return $r, $c ? { 0 => $c } : undef; } @@ -542,12 +545,12 @@ sub pp_grepwhile { $op = $op->first->sibling; my ($r2, $l2) = $self->inspect($op->sibling); - return $r2, $l2 if $r2 and zero $l2; + return $r2, $l2 if defined $r2 and zero $l2; my $c2 = count $l2; # First one to happen my ($r1, $l1) = $self->inspect($op); - return (add $r2, scale $c2, $r1), undef if $r1 and zero $l1 and not zero $l2; - diag Dumper [ [ $r1, $l1 ], [ $r2, $l2 ] ] if $DEBUG; + return (add $r2, scale $c2, $r1), undef if defined $r1 and zero $l1 + and not zero $l2; my $c1 = count $l1; $l2 = { $l2 => 1 } unless ref $l2; @@ -566,12 +569,12 @@ sub pp_mapwhile { $op = $op->first->sibling; my ($r2, $l2) = $self->inspect($op->sibling); - return $r2, $l2 if $r2 and zero $l2; + return $r2, $l2 if defined $r2 and zero $l2; my $c2 = count $l2; # First one to happen my ($r1, $l1) = $self->inspect($op); - return (add $r2, scale $c2, $r1), undef if $r1 and zero $l1 and not zero $l2; - diag Dumper [ [ $r1, $l1 ], [ $r2, $l2 ] ] if $DEBUG; + return (add $r2, scale $c2, $r1), undef if defined $r1 and zero $l1 + and not zero $l2; my $c1 = count $l1; $l2 = { $l2 => 1 } unless ref $l2; @@ -607,7 +610,7 @@ You can contact me by mail or on #perl @ FreeNode (vincent or Prof_Vince). =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