ljr/wcmtools/s2/S2/NodeSum.pm

125 lines
2.9 KiB
Perl
Executable File

#!/usr/bin/perl
#
package S2::NodeSum;
use strict;
use S2::Node;
use S2::NodeProduct;
use vars qw($VERSION @ISA);
$VERSION = '1.0';
@ISA = qw(S2::Node);
sub new {
my ($class, $lhs, $op, $rhs) = @_;
my $node = new S2::Node;
$node->{'lhs'} = $lhs;
$node->{'op'} = $op;
$node->{'rhs'} = $rhs;
bless $node, $class;
}
sub canStart {
my ($class, $toker) = @_;
S2::NodeProduct->canStart($toker);
}
sub parse {
my ($class, $toker) = @_;
my $lhs = parse S2::NodeProduct $toker;
$lhs->skipWhite($toker);
while ($toker->peek() == $S2::TokenPunct::PLUS ||
$toker->peek() == $S2::TokenPunct::MINUS) {
$lhs = parseAnother($toker, $lhs);
}
return $lhs;
}
sub parseAnother {
my ($toker, $lhs) = @_;
my $n = new S2::NodeSum();
$n->{'lhs'} = $lhs;
$n->addNode($n->{'lhs'});
$n->{'op'} = $toker->peek();
$n->eatToken($toker);
$n->skipWhite($toker);
$n->{'rhs'} = parse S2::NodeProduct $toker;
$n->addNode($n->{'rhs'});
$n->skipWhite($toker);
return $n;
}
sub getType {
my ($this, $ck, $wanted) = @_;
my $lt = $this->{'lhs'}->getType($ck, $wanted);
my $rt = $this->{'rhs'}->getType($ck, $wanted);
unless ($lt->equals($S2::Type::INT) ||
$lt->equals($S2::Type::STRING))
{
if ($this->{'lhs'}->makeAsString($ck)) {
$lt = $S2::Type::STRING;
} else {
S2::error($this->{'lhs'}, "Left hand side of " . $this->{'op'}->getPunct() .
" operator is " . $lt->toString() . ", not a string or integer");
}
}
unless ($rt->equals($S2::Type::INT) ||
$rt->equals($S2::Type::STRING))
{
if ($this->{'rhs'}->makeAsString($ck)) {
$rt = $S2::Type::STRING;
} else {
S2::error($this->{'rhs'}, "Right hand side of " . $this->{'op'}->getPunct() .
" operator is " . $rt->toString() . ", not a string or integer");
}
}
if ($this->{'op'} == $S2::TokenPunct::MINUS &&
($lt->equals($S2::Type::STRING) ||
$rt->equals($S2::Type::STRING))) {
S2::error($this->{'rhs'}, "Can't substract strings.");
}
if ($lt->equals($S2::Type::STRING) ||
$rt->equals($S2::Type::STRING)) {
return $this->{'myType'} = $S2::Type::STRING;
}
return $this->{'myType'} = $S2::Type::INT;
}
sub asS2 {
my ($this, $o) = @_;
$this->{'lhs'}->asS2($o);
$o->write(" " . $this->{'op'}->getPunct() . " ");
$this->{'rhs'}->asS2($o);
}
sub asPerl {
my ($this, $bp, $o) = @_;
$this->{'lhs'}->asPerl($bp, $o);
if ($this->{'myType'} == $S2::Type::STRING) {
$o->write(" . ");
} elsif ($this->{'op'} == $S2::TokenPunct::PLUS) {
$o->write(" + ");
} elsif ($this->{'op'} == $S2::TokenPunct::MINUS) {
$o->write(" - ");
}
$this->{'rhs'}->asPerl($bp, $o);
}