code: func newValueExpr(value interface{}) ast.ValueExpr {
  	if ve, ok := value.(*ValueExpr); ok {
  		return ve
  	}
  	ve := &ValueExpr{}
  	ve.SetValue(value)
  	types.DefaultTypeForValue(value, &ve.Type)
  	ve.projectionOffset = -1
  	return ve
  }
docs: // newValueExpr creates a ValueExpr with value, and sets default field type.