use strict;
use warnings;
+use Carp qw(confess);
+
use XSLoader;
BEGIN {
- our $VERSION = '0.05_03';
+ our $VERSION = '0.06';
XSLoader::load;
}
-use Carp qw(confess);
-
sub _assert_valid_identifier {
my ($name, $with_dollar) = @_;
my $bonus = $with_dollar ? '\$' : '';
my @bare_arms = qw(function method);
my %type_map = (
- function => { name => 'optional' },
+ function => {
+ name => 'optional',
+ default_arguments => 1,
+ check_argument_count => 0,
+ },
method => {
name => 'optional',
- shift => '$self',
+ default_arguments => 1,
+ check_argument_count => 0,
attrs => ':method',
+ shift => '$self',
+ },
+ classmethod => {
+ name => 'optional',
+ default_arguments => 1,
+ check_argument_count => 0,
+ attributes => ':method',
+ shift => '$class',
},
);
+for my $k (keys %type_map) {
+ $type_map{$k . '_strict'} = {
+ %{$type_map{$k}},
+ check_argument_count => 1,
+ };
+}
sub import {
my $class = shift;
? $proto
: [$proto, $bare_arms[$bare++] || confess(qq{Don't know what to do with "$proto"})]
;
- my ($name, $type) = @$item;
+ my ($name, $proto_type) = @$item;
_assert_valid_identifier $name;
- unless (ref $type) {
- # use '||' instead of 'or' to preserve $type in the error message
- $type = $type_map{$type}
- || confess qq["$type" doesn't look like a valid type (one of ${\join ', ', sort keys %type_map})];
+ unless (ref $proto_type) {
+ # use '||' instead of 'or' to preserve $proto_type in the error message
+ $proto_type = $type_map{$proto_type}
+ || confess qq["$proto_type" doesn't look like a valid type (one of ${\join ', ', sort keys %type_map})];
}
- $type->{name} ||= 'optional';
- $type->{name} =~ /^(?:optional|required|prohibited)\z/
- or confess qq["$type->{name}" doesn't look like a valid name attribute (one of optional, required, prohibited)];
- $type->{shift} and _assert_valid_identifier $type->{shift}, 1;
- $type->{attrs} and _assert_valid_attributes $type->{attrs};
+ my %type = %$proto_type;
+ my %clean;
+
+ $clean{name} = delete $type{name} || 'optional';
+ $clean{name} =~ /^(?:optional|required|prohibited)\z/
+ or confess qq["$clean{name}" doesn't look like a valid name attribute (one of optional, required, prohibited)];
+
+ $clean{shift} = delete $type{shift} || '';
+ _assert_valid_identifier $clean{shift}, 1 if $clean{shift};
+
+ $clean{attrs} = join ' ', map delete $type{$_} || (), qw(attributes attrs);
+ _assert_valid_attributes $clean{attrs} if $clean{attrs};
- $spec{$name} = $type;
+ $clean{default_arguments} =
+ exists $type{default_arguments}
+ ? !!delete $type{default_arguments}
+ : 1
+ ;
+ $clean{check_argument_count} = !!delete $type{check_argument_count};
+
+ %type and confess "Invalid keyword property: @{[keys %type]}";
+
+ $spec{$name} = \%clean;
}
for my $kw (keys %spec) {
my $type = $spec{$kw};
- $^H{HINTK_SHIFT_ . $kw} = $type->{shift} || '';
- $^H{HINTK_ATTRS_ . $kw} = $type->{attrs} || '';
- $^H{HINTK_NAME_ . $kw} =
- $type->{name} eq 'prohibited' ? FLAG_NAME_PROHIBITED :
- $type->{name} eq 'required' ? FLAG_NAME_REQUIRED :
- FLAG_NAME_OPTIONAL
+ my $flags =
+ $type->{name} eq 'prohibited' ? FLAG_ANON_OK :
+ $type->{name} eq 'required' ? FLAG_NAME_OK :
+ FLAG_ANON_OK | FLAG_NAME_OK
;
+ $flags |= FLAG_DEFAULT_ARGS if $type->{default_arguments};
+ $flags |= FLAG_CHECK_NARGS if $type->{check_argument_count};
+ $^H{HINTK_FLAGS_ . $kw} = $flags;
+ $^H{HINTK_SHIFT_ . $kw} = $type->{shift};
+ $^H{HINTK_ATTRS_ . $kw} = $type->{attrs};
$^H{+HINTK_KEYWORDS} .= "$kw ";
}
}
__END__
+=encoding UTF-8
+
=head1 NAME
Function::Parameters - subroutine definitions with parameter lists
use Function::Parameters;
+ # simple function
fun foo($bar, $baz) {
return $bar + $baz;
}
+ # function with prototype
fun mymap($fun, @args) :(&@) {
my @res;
for (@args) {
print "$_\n" for mymap { $_ * 2 } 1 .. 4;
+ # method with implicit $self
method set_name($name) {
$self->{name} = $name;
}
+ # function with default arguments
+ fun search($haystack, $needle = qr/^(?!)/, $offset = 0) {
+ ...
+ }
+
+ # method with default arguments
+ method skip($amount = 1) {
+ $self->{position} += $amount;
+ }
+
=cut
=pod
+ # use different keywords
use Function::Parameters {
proc => 'function',
meth => 'method',
The effect of C<fun foo($bar, $baz) {> is as if you'd written
C<sub foo { my ($bar, $baz) = @_; >, i.e. the parameter list is simply
-copied into C<my> and initialized from L<@_|perlvar/"@_">.
+copied into L<my|perlfunc/my-EXPR> and initialized from L<@_|perlvar/"@_">.
In addition you can use C<method>, which understands the same syntax as C<fun>
but automatically creates a C<$self> variable for you. So by writing
=head2 Customizing the generated keywords
You can customize the names of the keywords injected into your scope. To do
-that you pass a hash reference in the import list:
+that you pass a reference to a hash mapping keywords to types in the import
+list:
+
+ use Function::Parameters {
+ KEYWORD1 => TYPE1,
+ KEYWORD2 => TYPE2,
+ ...
+ };
+
+Or more concretely:
use Function::Parameters { proc => 'function', meth => 'method' }; # -or-
use Function::Parameters { proc => 'function' }; # -or-
- use Function::Parameters { meth => 'method' };
+ use Function::Parameters { meth => 'method' }; # etc.
The first line creates two keywords, C<proc> and C<meth> (for defining
functions and methods, respectively). The last two lines only create one
-keyword. Generally the hash keys can be any identifiers you want while the
-values have to be either C<function>, C<method>, or a hash reference (see
-below). The difference between C<function> and C<method> is that C<method>s
-automatically L<shift|perlfunc/shift> their first argument into C<$self>.
+keyword. Generally the hash keys (keywords) can be any identifiers you want
+while the values (types) have to be either a hash reference (see below) or
+C<'function'>, C<'method'>, C<'classmethod'>, C<'function_strict'>,
+C<'method_strict'>, or C<'classmethod_strict'>. The main difference between
+C<'function'> and C<'method'> is that C<'method'>s automatically
+L<shift|perlfunc/shift> their first argument into C<$self> (C<'classmethod'>s
+are similar but shift into C<$class>).
The following shortcuts are available:
=pod
The following shortcuts are deprecated and may be removed from a future version
-of the module:
+of this module:
# DEPRECATED
use Function::Parameters 'foo';
That is, if you want to pass arguments to L<Function::Parameters>, use a
hashref, not a list of strings.
-You can customize things even more by passing a hashref instead of C<function>
-or C<method>. This hash can have the following keys:
+You can customize the properties of the generated keywords even more by passing
+a hashref instead of a string. This hash can have the following keys:
=over
this keyword will automatically L<shift|perlfunc/shift> its first argument into
a local variable whose name is specified here.
-=item C<attrs>
+=item C<attributes>, C<attrs>
Valid values: strings that are valid source code for attributes. Any value
specified here will be inserted as a subroutine attribute in the generated
code. Thus:
- use Function::Parameters { sub_l => { attrs => ':lvalue' } };
+ use Function::Parameters { sub_l => { attributes => ':lvalue' } };
sub_l foo() {
...
}
...
}
+It is recommended that you use C<attributes> in new code but C<attrs> is also
+accepted for now.
+
+=item C<default_arguments>
+
+Valid values: booleans. This property is on by default, so you have to pass
+C<< default_arguments => 0 >> to turn it off. If it is disabled, using C<=> in
+a parameter list causes a syntax error. Otherwise it lets you specify
+default arguments directly in the parameter list:
+
+ fun foo($x, $y = 42, $z = []) {
+ ...
+ }
+
+turns into
+
+ sub foo {
+ my ($x, $y, $z) = @_;
+ $y = 42 if @_ < 2;
+ $z = [] if @_ < 3;
+ ...
+ }
+
+except that none of the parameters are in scope in the expressions that specify
+default values. Thus:
+
+ my $var = "outer";
+
+ fun foo($var, $wat = $var) {
+ # $wat will default to "outer", not to what was passed
+ # as the first argument!
+ ...
+ }
+
+This may change in a future version of this module.
+
+=item C<check_argument_count>
+
+Valid values: booleans. This property is off by default. If it is enabled, the
+generated code will include checks to make sure the number of passed arguments
+is correct (and otherwise throw an exception via L<Carp::croak|Carp>):
+
+ fun foo($x, $y = 42, $z = []) {
+ ...
+ }
+
+turns into
+
+ sub foo {
+ Carp::croak "Not enough arguments for fun foo" if @_ < 1;
+ Carp::croak "Too many arguments for fun foo" if @_ > 3;
+ my ($x, $y, $z) = @_;
+ $y = 42 if @_ < 2;
+ $z = [] if @_ < 3;
+ ...
+ }
+
=back
-Plain C<'function'> is equivalent to C<< { name => 'optional' } >>, and plain
-C<'method'> is equivalent to
-C<< { name => 'optional', shift => '$self', attrs => ':method' } >>.
+Plain C<'function'> is equivalent to:
+
+ {
+ name => 'optional',
+ default_arguments => 1,
+ check_argument_count => 0,
+ }
+
+(These are all default values so C<'function'> is also equivalent to C<{}>.)
+
+C<'function_strict'> is like C<'function'> but with
+C<< check_argument_count => 1 >>.
+
+C<'method'> is equivalent to:
+
+ {
+ name => 'optional',
+ default_arguments => 1,
+ check_argument_count => 0,
+ attributes => ':method',
+ shift => '$self',
+ }
+
+C<'method_strict'> is like C<'method'> but with
+C<< check_argument_count => 1 >>.
+
+C<'classmethod'> is equivalent to:
+
+ {
+ name => 'optional',
+ default_arguments => 1,
+ check_argument_count => 0,
+ attributes => ':method',
+ shift => '$class',
+ }
+
+C<'classmethod_strict'> is like C<'classmethod'> but with
+C<< check_argument_count => 1 >>.
=head2 Syntax and generated code
C<$bar-E<gt>foo([1], $bar[0])>. Yes. You can add parens to change the
interpretation of this code, but C<foo($bar[1], $bar[0])> will only trigger
a I<foo() called too early to check prototype> warning. This module attempts
-to fix all of this by adding a subroutine declaration before the definition,
+to fix all of this by adding a subroutine declaration before the function body,
so the parser knows the name (and possibly prototype) while it processes the
body. Thus C<fun foo($x) :($) { $x }> really turns into
-C<sub foo ($); sub foo ($) { my ($x) = @_; $x }>.
+C<sub foo ($) { sub foo ($); my ($x) = @_; $x }>.
-If you need L<subroutine attributes|perlsub/"Subroutine Attributes">, you can
+If you need L<subroutine attributes|perlsub/Subroutine-Attributes>, you can
put them after the parameter list with their usual syntax.
Syntactically, these new parameter lists live in the spot normally occupied
because normal attributes have to start with a letter while a prototype starts
with C<(>).
-As an example, the following declaration uses every feature available
-(subroutine name, parameter list, prototype, attributes, and implicit
-C<$self>):
+As an example, the following declaration uses every available feature
+(subroutine name, parameter list, default arguments, prototype, default
+attributes, attributes, argument count checks, and implicit C<$self>):
- method foo($x, $y, @z) :($;$@) :lvalue :Banana(2 + 2) {
+ method foo($x, $y, $z = sqrt 5) :($$$;$) :lvalue :Banana(2 + 2) {
...
}
And here's what it turns into:
- sub foo ($;$@); sub foo ($;$@) :lvalue :Banana(2 + 2) { my $self = shift; my ($x, $y, @z) = @_;
+ sub foo ($$$;$) :method :lvalue :Banana(2 + 2) {
+ sub foo ($$$;$);
+ Carp::croak "Not enough arguments for method foo" if @_ < 2;
+ Carp::croak "Too many arguments for method foo" if @_ > 4;
+ my $self = shift;
+ my ($x, $y, $z) = @_;
+ $z = sqrt 5 if @_ < 3;
...
}
And the generated code:
- my $coderef = sub (;$$) :lvalue :Gazebo((>:O)) { my ($p, $q) = @_;
+ my $coderef = sub (;$$) :lvalue :Gazebo((>:O)) {
+ # vvv only if check_argument_count is enabled vvv
+ Carp::croak "Not enough arguments for fun (anon)" if @_ < 2;
+ Carp::croak "Too many arguments for fun (anon)" if @_ > 2;
+ # ^^^ ^^^
+ my ($p, $q) = @_;
...
};
If you want to wrap L<Function::Parameters>, you just have to call its
C<import> method. It always applies to the file that is currently being parsed
-and its effects are lexical (i.e. it works like L<warnings> or L<strict>):
+and its effects are L<lexical|perlpragma> (i.e. it works like L<warnings> or
+L<strict>).
package Some::Wrapper;
use Function::Parameters ();
sub import {
Function::Parameters->import;
- # or Function::Parameters->import(@other_import_args);
+ # or Function::Parameters->import(@custom_import_args);
}
=head1 AUTHOR
projects / p5sagit/Function-Parameters.git / blobdiff