#!./perl -w
+# tests state variables
BEGIN {
chdir 't' if -d 't';
}
use strict;
-use feature "state";
+use feature ":5.10";
-plan tests => 25;
+plan tests => 123;
ok( ! defined state $uninit, q(state vars are undef by default) );
+# basic functionality
+
sub stateful {
state $x;
state $y = 1;
my $z = 2;
- return ($x++, $y++, $z++);
+ state ($t) //= 3;
+ return ($x++, $y++, $z++, $t++);
}
-my ($x, $y, $z) = stateful();
+my ($x, $y, $z, $t) = stateful();
is( $x, 0, 'uninitialized state var' );
is( $y, 1, 'initialized state var' );
is( $z, 2, 'lexical' );
+is( $t, 3, 'initialized state var, list syntax' );
-($x, $y, $z) = stateful();
+($x, $y, $z, $t) = stateful();
is( $x, 1, 'incremented state var' );
is( $y, 2, 'incremented state var' );
is( $z, 2, 'reinitialized lexical' );
+is( $t, 4, 'incremented state var, list syntax' );
-($x, $y, $z) = stateful();
+($x, $y, $z, $t) = stateful();
is( $x, 2, 'incremented state var' );
is( $y, 3, 'incremented state var' );
is( $z, 2, 'reinitialized lexical' );
+is( $t, 5, 'incremented state var, list syntax' );
+
+# in a nested block
sub nesting {
state $foo = 10;
is( $x, 12, 'outer state var' );
is( $y, 14, 'inner state var' );
+# in a closure
+
sub generator {
my $outer;
# we use $outer to generate a closure
is( $f1->(), 3, 'generator 1 again' );
is( $f2->(), 2, 'generator 2 once more' );
+# with ties
{
package countfetches;
our $fetchcount = 0;
::is( $fetchcount, 1, "fetch only called once" );
}
+# state variables are shared among closures
+
+sub gen_cashier {
+ my $amount = shift;
+ state $cash_in_store = 0;
+ return {
+ add => sub { $cash_in_store += $amount },
+ del => sub { $cash_in_store -= $amount },
+ bal => sub { $cash_in_store },
+ };
+}
+
+gen_cashier(59)->{add}->();
+gen_cashier(17)->{del}->();
+is( gen_cashier()->{bal}->(), 42, '$42 in my drawer' );
+
+# stateless assignment to a state variable
+
sub stateless {
- # stateless assignment
- (state $reinitme) = 42;
+ state $reinitme = 42;
++$reinitme;
}
is( stateless(), 43, 'stateless function, first time' );
-is( stateless(), 43, 'stateless function, second time' );
+is( stateless(), 44, 'stateless function, second time' );
+
+# array state vars
+
+sub stateful_array {
+ state @x;
+ push @x, 'x';
+ return $#x;
+}
+
+my $xsize = stateful_array();
+is( $xsize, 0, 'uninitialized state array' );
+
+$xsize = stateful_array();
+is( $xsize, 1, 'uninitialized state array after one iteration' );
+
+# hash state vars
+
+sub stateful_hash {
+ state %hx;
+ return $hx{foo}++;
+}
+
+my $xhval = stateful_hash();
+is( $xhval, 0, 'uninitialized state hash' );
+
+$xhval = stateful_hash();
+is( $xhval, 1, 'uninitialized state hash after one iteration' );
+
+# Recursion
+
+sub noseworth {
+ my $level = shift;
+ state $recursed_state = 123;
+ is($recursed_state, 123, "state kept through recursion ($level)");
+ noseworth($level - 1) if $level;
+}
+noseworth(2);
+
+# Assignment return value
+
+sub pugnax { my $x = state $y = 42; $y++; $x; }
+
+is( pugnax(), 42, 'scalar state assignment return value' );
+is( pugnax(), 43, 'scalar state assignment return value' );
+
+
+#
+# Test various blocks.
+#
+foreach my $x (1 .. 3) {
+ state $y = $x;
+ is ($y, 1, "foreach $x");
+}
+
+for (my $x = 1; $x < 4; $x ++) {
+ state $y = $x;
+ is ($y, 1, "for $x");
+}
+
+while ($x < 4) {
+ state $y = $x;
+ is ($y, 1, "while $x");
+ $x ++;
+}
+
+$x = 1;
+until ($x >= 4) {
+ state $y = $x;
+ is ($y, 1, "until $x");
+ $x ++;
+}
+
+$x = 0;
+$y = 0;
+{
+ state $z = $x;
+ $z ++;
+ $y ++;
+ is ($z, $y, "bare block $y");
+ redo if $y < 3
+}
+
+
+#
+# Check state $_
+#
+my @stones = qw [fred wilma barny betty];
+my $first = $stones [0];
+my $First = ucfirst $first;
+$_ = "bambam";
+foreach my $flint (@stones) {
+ state $_ = $flint;
+ is $_, $first, 'state $_';
+ ok /$first/, '/.../ binds to $_';
+ is ucfirst, $First, '$_ default argument';
+}
+is $_, "bambam", '$_ is still there';
+
+#
+# Goto.
+#
+my @simpsons = qw [Homer Marge Bart Lisa Maggie];
+again:
+ my $next = shift @simpsons;
+ state $simpson = $next;
+ is $simpson, 'Homer', 'goto 1';
+ goto again if @simpsons;
+
+goto Elvis;
+my $vi;
+{
+ state $calvin = ++ $vi;
+ Elvis: state $vile = ++ $vi;
+ redo unless defined $calvin;
+ is $calvin, 2, "goto 2";
+ is $vile, 1, "goto 3";
+ is $vi, 2, "goto 4";
+}
+my @presidents = qw [Taylor Garfield Ford Arthur Monroe];
+sub president {
+ my $next = shift @presidents;
+ state $president = $next;
+ goto &president if @presidents;
+ $president;
+}
+my $president_answer = $presidents [0];
+is president, $president_answer, '&goto';
+
+my @flowers = qw [Bluebonnet Goldenrod Hawthorn Peony];
+foreach my $f (@flowers) {
+ goto state $flower = $f;
+ ok 0, 'computed goto 0'; next;
+ Bluebonnet: ok 1, 'computed goto 1'; next;
+ Goldenrod: ok 0, 'computed goto 2'; next;
+ Hawthorn: ok 0, 'computed goto 3'; next;
+ Peony: ok 0, 'computed goto 4'; next;
+ ok 0, 'computed goto 5'; next;
+}
+
+#
+# map/grep
+#
+my @apollo = qw [Eagle Antares Odyssey Aquarius];
+my @result1 = map {state $x = $_;} @apollo;
+my @result2 = grep {state $x = /Eagle/} @apollo;
+{
+ local $" = "";
+ is "@result1", $apollo [0] x @apollo, "map";
+ is "@result2", "@apollo", "grep";
+}
+
+#
+# Reference to state variable.
+#
+sub reference {\state $x}
+my $ref1 = reference;
+my $ref2 = reference;
+is $ref1, $ref2, "Reference to state variable";
+
+#
+# Pre/post increment.
+#
+foreach my $x (1 .. 3) {
+ ++ state $y;
+ state $z ++;
+ is $y, $x, "state pre increment";
+ is $z, $x, "state post increment";
+}
+
+
+#
+# Substr
+#
+my $tintin = "Tin-Tin";
+my @thunderbirds = qw [Scott Virgel Alan Gordon John];
+my @thunderbirds2 = qw [xcott xxott xxxtt xxxxt xxxxx];
+foreach my $x (0 .. 4) {
+ state $c = \substr $tintin, $x, 1;
+ my $d = \substr ((state $tb = $thunderbirds [$x]), $x, 1);
+ $$c = "x";
+ $$d = "x";
+ is $tintin, "xin-Tin", "substr";
+ is $tb, $thunderbirds2 [$x], "substr";
+}
+
+
+#
+# Use with given.
+#
+my @spam = qw [spam ham bacon beans];
+foreach my $spam (@spam) {
+ given (state $spam = $spam) {
+ when ($spam [0]) {ok 1, "given"}
+ default {ok 0, "given"}
+ }
+}
+
+#
+# Redefine.
+#
+{
+ state $x = "one";
+ no warnings;
+ state $x = "two";
+ is $x, "two", "masked"
+}
+
+# normally closureless anon subs share a CV and pad. If the anon sub has a
+# state var, this would mean that it is shared. Check that this doesn't
+# happen
+
+{
+ my @f;
+ push @f, sub { state $x; ++$x } for 1..2;
+ $f[0]->() for 1..10;
+ is $f[0]->(), 11;
+ is $f[1]->(), 1;
+}
+
+# each copy of an anon sub should get its own 'once block'
+
+{
+ my $x; # used to force a closure
+ my @f;
+ push @f, sub { $x=0; state $s = $_[0]; $s } for 1..2;
+ is $f[0]->(1), 1;
+ is $f[0]->(2), 1;
+ is $f[1]->(3), 3;
+ is $f[1]->(4), 3;
+}
+
+
+
+
+foreach my $forbidden (<DATA>) {
+ chomp $forbidden;
+ no strict 'vars';
+ eval $forbidden;
+ like $@, qr/Initialization of state variables in list context currently forbidden/, "Currently forbidden: $forbidden";
+}
+__DATA__
+state ($a) = 1;
+(state $a) = 1;
+state @a = 1;
+state (@a) = 1;
+(state @a) = 1;
+state %a = ();
+state (%a) = ();
+(state %a) = ();
+state ($a, $b) = ();
+state ($a, @b) = ();
+(state $a, state $b) = ();
+(state $a, $b) = ();
+(state $a, my $b) = ();
+(state $a, state @b) = ();
+(state $a, local @b) = ();
+(state $a, undef, state $b) = ();
+state ($a, undef, $b) = ();