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it turns out that initial whitespaces are required even in "programli…
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…sting" blocks. Reported by sorear++
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@moritz
moritz committed Apr 14, 2010
1 parent 0732332 commit 3c98bf3
Showing 1 changed file with 122 additions and 122 deletions.
244 changes: 122 additions & 122 deletions src/subs-n-sigs.pod
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Expand Up @@ -18,11 +18,11 @@ call the subroutine.

=begin programlisting

sub panic() {
say "Oh no! Something has gone most terribly wrong!";
}

panic();
sub panic() {
say "Oh no! Something has gone most terribly wrong!";
}
panic();

=end programlisting

Expand All @@ -34,18 +34,18 @@ you can use C<our> to put it in the package.

=begin programlisting

{
our sub eat() {
say "om nom nom";
}

sub drink() {
say "glug glug";
}
}

eat(); # om nom nom
drink(); # fails, can't drink outside of the block
{
our sub eat() {
say "om nom nom";
}
sub drink() {
say "glug glug";
}
}
eat(); # om nom nom
drink(); # fails, can't drink outside of the block

=end programlisting

Expand All @@ -57,19 +57,19 @@ names of the dance moves, and the values are anonymous subroutines.

=begin programlisting

my $dance = '';
my %moves =
hands-over-head => sub { $dance ~= '/o\ ' },
bird-arms => sub { $dance ~= '|/o\| ' },
left => sub { $dance ~= '>o ' },
right => sub { $dance ~= 'o< ' },
arms-up => sub { $dance ~= '\o/ ' };

my @awesome-dance = <arms-up bird-arms right hands-over-head>;
for @awesome-dance -> $move {
%moves{$move}.();
}
say $dance;
my $dance = '';
my %moves =
hands-over-head => sub { $dance ~= '/o\ ' },
bird-arms => sub { $dance ~= '|/o\| ' },
left => sub { $dance ~= '>o ' },
right => sub { $dance ~= 'o< ' },
arms-up => sub { $dance ~= '\o/ ' };
my @awesome-dance = <arms-up bird-arms right hands-over-head>;
for @awesome-dance -> $move {
%moves{$move}.();
}
say $dance;

=end programlisting

Expand All @@ -93,12 +93,12 @@ that incoming arguments should be bound to.

=begin programlisting

sub order-beer($type, $pints) {
say ($pints == 1 ?? 'A pint' !! "$pints pints") ~ " of $type, please."
}

order-beer('Hobgoblin', 1); # A pint of Hobgoblin, please.
order-beer('Zlatý Bažant', 3); # 3 pints of Zlatý Bažant, please.
sub order-beer($type, $pints) {
say ($pints == 1 ?? 'A pint' !! "$pints pints") ~ " of $type, please."
}
order-beer('Hobgoblin', 1); # A pint of Hobgoblin, please.
order-beer('Zlatý Bažant', 3); # 3 pints of Zlatý Bažant, please.

=end programlisting

Expand All @@ -115,14 +115,14 @@ called with the constant argument.

=begin programlisting

sub make-it-more-so($it is rw) {
$it ~= substr($it, $it.chars - 1) x 5;
}

my $happy = "yay!";
make-it-more-so($happy);
say $happy; # yay!!!!!!
make-it-more-so("uh-oh"); # Fails; can't modify a constant
sub make-it-more-so($it is rw) {
$it ~= substr($it, $it.chars - 1) x 5;
}
my $happy = "yay!";
make-it-more-so($happy);
say $happy; # yay!!!!!!
make-it-more-so("uh-oh"); # Fails; can't modify a constant

=end programlisting

Expand All @@ -132,14 +132,14 @@ mark the parameter C<is copy>.

=begin programlisting

sub say-it-one-higher($it is copy) {
$it++;
say $it;
}

my $unanswer = 41;
say-it-one-higher($unanswer); # 42
say-it-one-higher(41); # 42
sub say-it-one-higher($it is copy) {
$it++;
say $it;
}
my $unanswer = 41;
say-it-one-higher($unanswer); # 42
say-it-one-higher(41); # 42

=end programlisting

Expand All @@ -159,15 +159,15 @@ something that matches this constraint will cause the call to fail.

=begin programlisting

sub shout-them(@words) {
for @words -> $w {
print uc("$w ");
}
}

my @last_words = <do not want>;
shout-them(@last_words); # DO NOT WANT
shout-them('help'); # Fails; a string is not iterable
sub shout-them(@words) {
for @words -> $w {
print uc("$w ");
}
}
my @last_words = <do not want>;
shout-them(@last_words); # DO NOT WANT
shout-them('help'); # Fails; a string is not iterable

=end programlisting

Expand All @@ -180,13 +180,13 @@ at the start.

=begin programlisting

sub do-it-lots(&it, $how-many-times) {
for 1..$how-many-times {
it();
}
}

do-it-lots(sub { say "Eating a stroopwafel" }, 10);
sub do-it-lots(&it, $how-many-times) {
for 1..$how-many-times {
it();
}
}
do-it-lots(sub { say "Eating a stroopwafel" }, 10);

=end programlisting

Expand Down Expand Up @@ -241,13 +241,13 @@ respective order. When that happens, it is often easier to call them by name
instead:

=begin programlisting

sub order-beer($type, $pints) {
say ($pints == 1 ?? 'A pint' !! "$pints pints") ~ " of $type, please."
}

order-beer(type => 'Hobgoblin', pints => 1); # A pint of Hobgoblin, please.
order-beer(pints => 3, type => 'Zlatý Bažant'); # 3 pints of Zlatý Bažant, please.
sub order-beer($type, $pints) {
say ($pints == 1 ?? 'A pint' !! "$pints pints") ~ " of $type, please."
}
order-beer(type => 'Hobgoblin', pints => 1); # A pint of Hobgoblin, please.
order-beer(pints => 3, type => 'Zlatý Bažant'); # 3 pints of Zlatý Bažant, please.

=end programlisting

Expand Down Expand Up @@ -285,12 +285,12 @@ The name of named parameters is not tied to the variable name that is used
inside the subroutine.

=begin programlisting

sub announce-time(:dinner($supper) = '8pm') {
say "We eat dinner at $supper";
}

announce-time(dinner => '9pm'); # We eat dinner at 9pm
sub announce-time(:dinner($supper) = '8pm') {
say "We eat dinner at $supper";
}
announce-time(dinner => '9pm'); # We eat dinner at 9pm

=end programlisting

Expand All @@ -305,9 +305,9 @@ lines mean the same thing:

=begin programlisting

announce-time(dinner => '9pm');
announce-time(:dinner('9pm'));
announce-time(:dinner<9pm>);
announce-time(dinner => '9pm');
announce-time(:dinner('9pm'));
announce-time(:dinner<9pm>);

=end programlisting

Expand Down Expand Up @@ -368,14 +368,14 @@ arguments to another routine:

=begin programlisting

sub debug-wrapper(&code, *@positional, *%named) {
warn "Calling '&code.name()' with arguments "
~ "@positional.perl(), %named.perl()\n";
code(|@positional, %named);
warn "... back from '&code.name()'\n";
}

debug-wrapper(&order-shrimps, 4, from => 'Atlantic Ocean');
sub debug-wrapper(&code, *@positional, *%named) {
warn "Calling '&code.name()' with arguments "
~ "@positional.perl(), %named.perl()\n";
code(|@positional, %named);
warn "... back from '&code.name()'\n";
}
debug-wrapper(&order-shrimps, 4, from => 'Atlantic Ocean');

=end programlisting

Expand All @@ -388,18 +388,18 @@ return values instead:

=begin programlisting

my %moves =
hands-over-head => sub { return '/o\ ' },
bird-arms => sub { return '|/o\| ' },
left => sub { return '>o ' },
right => sub { return 'o< ' },
arms-up => sub { return '\o/ ' };

my @awesome-dance = <arms-up bird-arms right hands-over-head>;
for @awesome-dance -> $move {
print %moves{$move}.();
}
print "\n";
my %moves =
hands-over-head => sub { return '/o\ ' },
bird-arms => sub { return '|/o\| ' },
left => sub { return '>o ' },
right => sub { return 'o< ' },
arms-up => sub { return '\o/ ' };
my @awesome-dance = <arms-up bird-arms right hands-over-head>;
for @awesome-dance -> $move {
print %moves{$move}.();
}
print "\n";

=end programlisting

Expand All @@ -409,15 +409,15 @@ returned:

=begin programlisting

sub menu {
if rand < 0.5 {
return ('fish', 'white wine')
} else {
return ('steak', 'read wine');
}
}

my ($food, $beverage) = menu();
sub menu {
if rand < 0.5 {
return ('fish', 'white wine')
} else {
return ('steak', 'read wine');
}
}
my ($food, $beverage) = menu();

=end programlisting

Expand All @@ -426,15 +426,15 @@ inside a subroutine is returned. So the example can be simplified to

=begin programlisting

sub menu {
if rand < 0.5 {
'fish', 'white wine'
} else {
'steak', 'read wine';
}
}

my ($food, $beverage) = menu();
sub menu {
if rand < 0.5 {
'fish', 'white wine'
} else {
'steak', 'read wine';
}
}
my ($food, $beverage) = menu();

=end programlisting

Expand Down

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