broke lists and objects, made strings nodes

fixing an old flaw in the design, namely that assignment nodes have
values that are just interface{} instead of actual parse nodes

node.go

@@ -143,7 +143,7 @@ func (n *commentNode) eval(ctx map[string]interface{}) (interface{}, error) {
 
 type assignmentNode struct {
 	name  string
-	value interface{}
+	value node
 }
 
 func (n *assignmentNode) Type() nodeType {
@@ -177,7 +177,9 @@ func (n *assignmentNode) String() string {
 func (n *assignmentNode) pretty(w io.Writer, prefix string) error {
 	fmt.Fprintf(w, "%sassign{\n", prefix)
 	fmt.Fprintf(w, "%s%sname: %s\n", prefix, indent, n.name)
-	fmt.Fprintf(w, "%s%svalue: %v\n", prefix, indent, n.value)
+	if err := n.value.pretty(w, fmt.Sprintf("%s%svalue: ", prefix, indent)); err != nil {
+		return err
+	}
 	fmt.Fprintf(w, "%s}\n", prefix)
 	return nil
 }
@@ -192,16 +194,21 @@ func (n *assignmentNode) eval(ctx map[string]interface{}) (interface{}, error) {
 
 type stringNode string
 
-func (s stringNode) Type() nodeType {
+func (s *stringNode) Type() nodeType {
 	return n_string
 }
 
 func (s *stringNode) parse(p *parser) error {
+	t := p.next()
+	if t.t != t_string {
+		return fmt.Errorf("unexpected %s while looking for string token", t.t)
+	}
+	*s = stringNode(t.s)
 	return nil
 }
 
 func (s *stringNode) pretty(w io.Writer, prefix string) error {
-	_, err := fmt.Fprintf(w, "%s%s", prefix, string(*s))
+	_, err := fmt.Fprintf(w, "%s%s\n", prefix, string(*s))
 	return err
 }
 

parse.go

@@ -73,23 +73,27 @@ func (p *parser) ensureNext(tt tokenType, context string) error {
 
 // parse the next value.  This is to be executed in a context where we know we
 // want something that is a value to come next, such as after an equals sign.
-func (p *parser) parseValue() (interface{}, error) {
+func (p *parser) parseValue() (node, error) {
 	for {
-		t := p.next()
+		t := p.peek()
 		switch t.t {
 		case t_error:
 			return nil, fmt.Errorf("parse error: saw lex error when looking for value: %v", t.s)
 		case t_eof:
 			return nil, fmt.Errorf("parse error: unexpected eof when looking for value")
 		case t_string:
-			return t.s, nil
-		case t_real_number, t_imaginary_number:
-			p.unread(t)
-			return p.number()
-		case t_list_start:
-			return p.parseList(make(list, 0, 4))
-		case t_object_start:
-			return p.parseObject(make(object))
+			n := new(stringNode)
+			if err := n.parse(p); err != nil {
+				return nil, err
+			}
+			return n, nil
+		// case t_real_number, t_imaginary_number:
+		// 	p.unread(t)
+		// 	return p.number()
+		// case t_list_start:
+		// 	return p.parseList(make(list, 0, 4))
+		// case t_object_start:
+		// 	return p.parseObject(make(object))
 		default:
 			return nil, fmt.Errorf("parse error: unexpected %v token while looking for value", t.t)
 		}