Method stringHelper

dql/math.go:378–415

stringHelper does simple DFS to convert MathTree to string. nolint: unused

(buf *bytes.Buffer)

// stringHelper does simple DFS to convert MathTree to string.
// nolint: unused
func (t *MathTree) stringHelper(buf *bytes.Buffer) {
	x.AssertTruef(t != nil, "Nil Math tree")
	if t.Var != "" {
		// Leaf node.
		x.Check2(buf.WriteString(t.Var))
		return
	}
	if t.Const.Value != nil {
		// Leaf node.
		var leafStr int
		var err error
		switch t.Const.Tid {
		case types.FloatID:
			leafStr, err = buf.WriteString(strconv.FormatFloat(
				t.Const.Value.(float64), 'E', -1, 64))
		case types.IntID:
			leafStr, err = buf.WriteString(strconv.FormatInt(t.Const.Value.(int64), 10))
		}
		x.Check2(leafStr, err)
		return
	}
	// Non-leaf node.
	x.Check2(buf.WriteRune('('))
	switch t.Fn {
	case "+", "-", "/", "*", "%", "exp", "ln", "cond", "min",
		"sqrt", "max", "<", ">", "<=", ">=", "==", "!=", "u-",
		"logbase", "pow", "dot":
		x.Check2(buf.WriteString(t.Fn))
	default:
		x.Fatalf("Unknown operator: %q", t.Fn)
	}

	for _, c := range t.Child {
		x.Check2(buf.WriteRune(' '))
		c.stringHelper(buf)
	}
	x.Check2(buf.WriteRune(')'))
}