Fix a few segfaults

2 files changed, 6 insertions, 1 deletions

diff --git a/evaluator.cpp b/evaluator.cpp
index c5721ae..954a488 100644
--- a/evaluator.cpp
+++ b/evaluator.cpp
@@ -13,6 +13,9 @@ evaluator::evaluate(
 	value * l,
 	value * r)
 {
+	if (!l || !r) {
+		return default_evaluate(l, r);
+	}
 	enum value_type l_type = l->get_type();
 	enum value_type r_type = r->get_type();
 	switch(l_type) {
diff --git a/value.cpp b/value.cpp
index bc7a8b8..1201344 100644
--- a/value.cpp
+++ b/value.cpp
@@ -31,7 +31,9 @@ tree_value::simplify()
 	if (!m_evaluator) {
 		return this->clone();
 	}
-	return m_evaluator->evaluate(m_lchild->simplify(), m_rchild->simplify());
+	return m_evaluator->evaluate(
+			m_lchild ? m_lchild->simplify() : NULL,
+			m_rchild ? m_rchild->simplify() : NULL);
 }
 
 value *