Fix printing of binary operators with different precedences

Author: antonmedv

parser_test.go

@@ -49,6 +49,18 @@ var parseTests = []parseTest{
 		"(1 - 2) * 3",
 		binaryNode{"*", binaryNode{"-", numberNode{1}, numberNode{2}}, numberNode{3}},
 	},
+	{
+		"a or b or c",
+		binaryNode{"or", binaryNode{"or", nameNode{"a"}, nameNode{"b"}}, nameNode{"c"}},
+	},
+	{
+		"a or b and c",
+		binaryNode{"or", nameNode{"a"}, binaryNode{"and", nameNode{"b"}, nameNode{"c"}}},
+	},
+	{
+		"(a or b) and c",
+		binaryNode{"and", binaryNode{"or", nameNode{"a"}, nameNode{"b"}}, nameNode{"c"}},
+	},
 	{
 		"2**4-1",
 		binaryNode{"-", binaryNode{"**", numberNode{2}, numberNode{4}}, numberNode{1}},

print.go

@@ -37,11 +37,11 @@ func (n unaryNode) String() string {
 	case "!", "not":
 		return fmt.Sprintf("%v %v", n.operator, n.node)
 	}
-	return fmt.Sprintf("%v%v", n.operator, n.node)
+	return fmt.Sprintf("(%v%v)", n.operator, n.node)
 }
 
 func (n binaryNode) String() string {
-	return fmt.Sprintf("%v %v %v", n.left, n.operator, n.right)
+	return fmt.Sprintf("(%v %v %v)", n.left, n.operator, n.right)
 }
 
 func (n propertyNode) String() string {
@@ -114,7 +114,7 @@ func (n mapNode) String() string {
 func (n pairNode) String() string {
 	switch n.key.(type) {
 	case binaryNode, unaryNode:
-		return fmt.Sprintf("(%v): %v", n.key, n.value)
+		return fmt.Sprintf("%v: %v", n.key, n.value)
 	}
 	return fmt.Sprintf("%q: %v", n.key, n.value)
 }

print_test.go

@@ -31,6 +31,18 @@ var printTests = []printTest{
 		builtinNode{"len", []Node{identifierNode{"array"}}},
 		"len(array)",
 	},
+	{
+		binaryNode{"or", binaryNode{"or", nameNode{"a"}, nameNode{"b"}}, nameNode{"c"}},
+		"((a or b) or c)",
+	},
+	{
+		binaryNode{"or", nameNode{"a"}, binaryNode{"and", nameNode{"b"}, nameNode{"c"}}},
+		"(a or (b and c))",
+	},
+	{
+		binaryNode{"and", binaryNode{"or", nameNode{"a"}, nameNode{"b"}}, nameNode{"c"}},
+		"((a or b) and c)",
+	},
 }
 
 func TestPrint(t *testing.T) {