WSDL (Web Service Description Language)

WSDL is an XML-based language that provides a model for describing web services. It describes the location and the name of a service as well as the operation or function the service provides. It contains a series of definitions about a service. Some major elements of a WSDL document are listed in Table.

In order to generate a WSDL document more conveniently, we define as follows the date type Opr_Info to record the content of the important elements in a WSDL document.

data Opr_Info = (Opr_InN, Opr_InT, Opr_OutT, Opr_Name)

The type Opr_Info has four child types: Opr_InN (in- put parameter names), Opr_InT (input parameter types), Opr_OutT (return value’s type) and Opr_Name (the name of an operation). The type Opr_Info can be obtained through parsing source codes.