Node Resolved implementation now checks expressions too (#30)

Author: ajnavarro

sql/plan/filter.go

@@ -19,7 +19,7 @@ func (p *Filter) Schema() sql.Schema {
 }
 
 func (p *Filter) Resolved() bool {
-	return p.UnaryNode.Child.Resolved()
+	return p.UnaryNode.Child.Resolved() && p.expression.Resolved()
 }
 
 func (p *Filter) RowIter() (sql.RowIter, error) {

sql/plan/project.go

@@ -33,7 +33,16 @@ func (p *Project) Schema() sql.Schema {
 }
 
 func (p *Project) Resolved() bool {
-	return p.UnaryNode.Child.Resolved()
+	return p.UnaryNode.Child.Resolved() && p.expressionsResolved()
+}
+
+func (p *Project) expressionsResolved() bool {
+	for _, e := range p.expressions {
+		if !e.Resolved() {
+			return false
+		}
+	}
+	return true
 }
 
 func (p *Project) RowIter() (sql.RowIter, error) {

sql/plan/sort.go

@@ -32,7 +32,16 @@ func NewSort(sortFields []SortField, child sql.Node) *Sort {
 }
 
 func (s *Sort) Resolved() bool {
-	return s.UnaryNode.Child.Resolved()
+	return s.UnaryNode.Child.Resolved() && s.expressionsResolved()
+}
+
+func (p *Sort) expressionsResolved() bool {
+	for _, f := range p.sortFields {
+		if !f.Column.Resolved() {
+			return false
+		}
+	}
+	return true
 }
 
 func (s *Sort) Schema() sql.Schema {