Language Environment Interface Reference

Which Language Environment Interfaces Should I Provide?

When you write a language environment, you must determine which interfaces to provide. Your choices depend on what you intend the language environment to do. For example, if the language environment will be accessing database data, you'll make different choices than if it is for a scripting language. The following section describes the Net.Data language environment interfaces.

dtw_execute()

You must provide the dtw_execute() interface to pass input parameters from the macro; it is the only required interface for every language environment. Net.Data passes all input parameters to dtw_execute() through the language environment communication structure, dtw_lei_t .

dtw_initialize()

Provide the dtw_initialize() interface to allocate or initialize data. Net.Data calls this interface only once for each macro invocation, before the first function call to your language environment. If there are no function calls to your language environment, Net.Data does not call the dtw_initialize() interface.

dtw_cleanup()

Provide the dtw_cleanup() interface when you provide a dtw_initialize() interface, and you want to release any resources.

dtw_getNextRow()

Provide the dtw_getNextRow() interface as part of a database language environment or a language environment that can process data a row at a time. This interface is called if Net.Data is running on the OS/400(R) or OS/390 operating systems.