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|
package Catmandu::Emit;
# eval context ->
use Catmandu::Sane;
our $VERSION = '1.2020';
use Catmandu::Util qw(:is :string require_package);
use Clone qw(clone);
require Catmandu; # avoid circular dependencies
sub _eval_emit {
eval $_[0];
}
# <- eval context
use B ();
use Moo::Role;
# global state ->
sub _reject {
state $reject = {};
}
sub _generate_label {
state $num_labels = 0;
my $label = "__CATMANDU__FIX__${num_labels}";
$num_labels++;
$label;
}
sub _reject_label {
state $reject_label = _generate_label;
}
sub _generate_var {
state $num_vars = 0;
my $var = "\$__catmandu__${num_vars}";
$num_vars++;
$var;
}
# <- global state
sub _eval_sub {
my ($self, @args) = @_;
local $@;
_eval_emit($self->_emit_sub(@args)) or Catmandu::Error->throw($@);
}
sub _emit_sub {
my ($self, $body, %opts) = @_;
my $captures = $opts{captures} ||= {};
my $perl = "sub {";
if (my $args = $opts{args}) {
$perl .= 'my (' . join(', ', @$args) . ') = @_;';
}
$perl .= $body;
$perl .= "};";
my @captured_vars = map {
$self->_emit_declare_vars($_,
'$_[1]->{' . $self->_emit_string($_) . '}');
} keys %$captures;
$perl = join('', @captured_vars, $perl);
return $perl, $captures;
}
sub _emit_declare_vars {
my ($self, $var, $val) = @_;
$var = "(" . join(", ", @$var) . ")" if is_array_ref($var);
$val = "(" . join(", ", @$val) . ")" if is_array_ref($val);
if (defined $val) {
return "my ${var} = ${val};";
}
"my ${var};";
}
sub _emit_branch {
my ($self, $test, $pass, $fail) = @_;
"if (${test}) {${pass}} else {${fail}}";
}
sub _emit_call {
my ($self, $sub_var, @args) = @_;
"${sub_var}->(" . join(', ', @args) . ")";
}
sub _emit_iterate_array {
my ($self, $var, $cb) = @_;
my $perl = "";
my $i = $self->_generate_var;
# loop backwards so that deletions are safe
$perl .= "for (my ${i} = \@{${var}} - 1; ${i} >= 0; ${i}--) {";
$perl .= $cb->("${var}->[${i}]", up_var => $var, index => $i);
$perl .= "}";
$perl;
}
sub _emit_iterate_hash {
my ($self, $var, $cb) = @_;
my $perl = "";
my $k = $self->generate_var;
$perl .= "for my ${k} (keys(\%{${var}})) {";
$perl .= $cb->("${var}->{${k}}", up_var => $var, key => $k);
$perl .= "}";
$perl;
}
sub _emit_assign_cb {
my ($self, $var, $cb_var, %opts) = @_;
my $val_var = $self->_generate_var;
my $cancel_var = $self->_generate_var;
my $delete_var = $self->_generate_var;
my $perl = "";
$perl
.= "my (${val_var}, ${cancel_var}, ${delete_var}) = ${cb_var}->(${var});";
$perl .= "if (${delete_var}) {";
$perl .= $self->_emit_delete(%opts);
$perl .= "} elsif (!${cancel_var}) {";
$perl .= $self->_emit_assign($var, $val_var, %opts);
$perl .= "}";
$perl;
}
sub _emit_assign {
my ($self, $var, $val, %opts) = @_;
my $l_var = $var;
if (my $up_var = $opts{up_var}) {
if (defined(my $key = $opts{key})) {
$l_var = "${up_var}->{${key}}";
}
elsif (defined(my $index = $opts{index})) {
$l_var = "${up_var}->[${index}]";
}
else {
Catmandu::BadArg->throw('up_var without key or index');
}
}
"${l_var} = ${val};";
}
sub _emit_delete {
my ($self, %opts) = @_;
my $up_var = $opts{up_var};
if (!defined($up_var)) {
# TODO deleting the root object is equivalent to reject
$self->_emit_reject;
}
elsif (defined(my $key = $opts{key})) {
"delete ${up_var}->{${key}}";
}
elsif (defined(my $idx = $opts{index})) {
"splice(\@{${up_var}}, ${idx}, 1)";
}
else {
Catmandu::BadArg->throw('up_var without key or index');
}
}
sub _emit_value {
my ($self, $val) = @_;
## undef
return 'undef' unless defined $val;
## numbers
# we don't quote ints and floats unless there are leading
# (and for floats trailing) zero's
if (is_integer($val)) {
return $val;
}
if (is_float($val) && $val !~ /0$/) {
return $val;
}
## strings
$self->_emit_string($val);
}
sub _emit_string {
my ($self, $str) = @_;
B::perlstring($str);
}
sub _emit_reject {
my ($self) = @_;
'goto ' . $self->_reject_label . ';';
}
1;
__END__
=pod
=head1 NAME
Catmandu::Emit - Role with helper methods for code emitting
=cut
|
