Sub::Quote - efficient generation of subroutines via string eval |
Sub::Quote - efficient generation of subroutines via string eval
package Silly;
use Sub::Quote qw(quote_sub unquote_sub quoted_from_sub);
quote_sub 'Silly::kitty', q{ print "meow" };
quote_sub 'Silly::doggy', q{ print "woof" };
my $sound = 0;
quote_sub 'Silly::dagron', q{ print ++$sound % 2 ? 'burninate' : 'roar' }, { '$sound' => \$sound };
And elsewhere:
Silly->kitty; # meow Silly->doggy; # woof Silly->dagron; # burninate Silly->dagron; # roar Silly->dagron; # burninate
This package provides performant ways to generate subroutines from strings.
my $coderef = quote_sub 'Foo::bar', q{ print $x++ . "\n" }, { '$x' => \0 };
Arguments: ?$name, $code, ?\%captures, ?\%options
$name
is the subroutine where the coderef will be installed.
$code
is a string that will be turned into code.
\%captures
is a hashref of variables that will be made available to the
code. The keys should be the full name of the variable to be made available,
including the sigil. The values should be references to the values. The
variables will contain copies of the values. See the SYNOPSIS's
Silly::dagron
for an example using captures.
my $coderef = unquote_sub $sub;
Forcibly replace subroutine with actual code.
If $sub is not a quoted sub, this is a no-op.
my $data = quoted_from_sub $sub;
my ($name, $code, $captures, $compiled_sub) = @$data;
Returns original arguments to quote_sub, plus the compiled version if this sub has already been unquoted.
Note that $sub can be either the original quoted version or the compiled version for convenience.
my $prelude = capture_unroll '$captures', { '$x' => 1, '$y' => 2, }, 4;
my $inlined_code = inlinify q{ my ($x, $y) = @_;
print $x + $y . "\n"; }, '$x, $y', $prelude;
Takes a string of code, a string of arguments, a string of code which acts as a ``prelude'', and a Boolean representing whether or not to localize the arguments.
my $quoted_value = quotify $value;
Quotes a single (non-reference) scalar value for use in a code string. Numbers
aren't treated specially and will be quoted as strings, but undef will quoted as
undef()
.
my $prelude = capture_unroll '$captures', { '$x' => 1, '$y' => 2, }, 4;
Arguments: $from, \%captures, $indent
Generates a snippet of code which is suitable to be used as a prelude for
inlinify. $from
is a string will be used as a hashref in the resulting
code. The keys of %captures
are the names of the variables and the values
are ignored. $indent
is the number of spaces to indent the result by.
my $hash = { coderef => qsub q{ print "hello"; }, other => 5, };
Arguments: $code
Works exactly like quote_sub, but includes a prototype to only accept a single parameter. This makes it easier to include in hash structures or lists.
Much of this is just string-based code-generation, and as a result, a few caveats apply.
Calling return
from a quote_sub'ed sub will not likely do what you intend.
Instead of returning from the code you defined in quote_sub
, it will return
from the overall function it is composited into.
So when you pass in:
quote_sub q{ return 1 if $condition; $morecode }
It might turn up in the intended context as follows:
sub foo {
<important code a> do { return 1 if $condition; $morecode }; <important code b>
}
Which will obviously return from foo, when all you meant to do was return from the code context in quote_sub and proceed with running important code b.
Sub::Quote
preserves the environment of the code creating the
quoted subs. This includes the package, strict, warnings, and any
other lexical pragmas. This is done by prefixing the code with a
block that sets up a matching environment. When inlining Sub::Quote
subs, care should be taken that user pragmas won't effect the rest
of the code.
See Moo for support and contact information.
See Moo for authors.
See Moo for the copyright and license.
Sub::Quote - efficient generation of subroutines via string eval |