ljr/wcmtools/s2/S2/NodeIncExpr.pm

89 lines
2.0 KiB
Perl
Executable File

#!/usr/bin/perl
#
package S2::NodeIncExpr;
use strict;
use S2::Node;
use S2::NodeTerm;
use S2::TokenPunct;
use vars qw($VERSION @ISA);
$VERSION = '1.0';
@ISA = qw(S2::Node);
sub new {
my ($class, $n) = @_;
my $node = new S2::Node;
bless $node, $class;
}
sub canStart {
my ($class, $toker) = @_;
return $toker->peek() == $S2::TokenPunct::INCR ||
$toker->peek() == $S2::TokenPunct::DEC ||
S2::NodeTerm->canStart($toker);
}
sub parse {
my ($class, $toker) = @_;
my $n = new S2::NodeIncExpr;
if ($toker->peek() == $S2::TokenPunct::INCR ||
$toker->peek() == $S2::TokenPunct::DEC) {
$n->{'bPre'} = 1;
$n->{'op'} = $toker->peek();
$n->setStart($n->eatToken($toker));
$n->skipWhite($toker);
}
my $expr = parse S2::NodeTerm $toker;
$n->addNode($expr);
if ($toker->peek() == $S2::TokenPunct::INCR ||
$toker->peek() == $S2::TokenPunct::DEC) {
if ($n->{'bPre'}) {
S2::error($toker->peek(), "Unexpected " . $toker->peek()->getPunct());
}
$n->{'bPost'} = 1;
$n->{'op'} = $toker->peek();
$n->eatToken($toker);
$n->skipWhite($toker);
}
if ($n->{'bPre'} || $n->{'bPost'}) {
$n->{'expr'} = $expr;
return $n;
}
return $expr;
}
sub getType {
my ($this, $ck, $wanted) = @_;
my $t = $this->{'expr'}->getType($ck);
unless ($this->{'expr'}->isLValue() &&
$t->equals($S2::Type::INT)) {
S2::error($this->{'expr'}, "Post/pre-increment must operate on an integer lvalue");
}
return $t;
}
sub asS2 {
my ($this, $o) = @_;
if ($this->{'bPre'}) { $o->write($this->{'op'}->getPunct()); }
$this->{'expr'}->asS2($o);
if ($this->{'bPost'}) { $o->write($this->{'op'}->getPunct()); }
}
sub asPerl {
my ($this, $bp, $o) = @_;
if ($this->{'bPre'}) { $o->write($this->{'op'}->getPunct()); }
$this->{'expr'}->asPerl($bp, $o);
if ($this->{'bPost'}) { $o->write($this->{'op'}->getPunct()); }
}