import

The import command is used to load external libraries. Drop the library file .dll (or .so or .dylib) to the same folder contains the executable, one can use following command to import it.

import (1)
# (1) string, external library name

There is no need to include file extension.

If the external library has only one function exported and the name of which coincides with the external library name, there is no need to explicitly import the library. It will be done automatically.

Say for example, the external library ElementExample.dll contains the corresponding function to create an external ElementExample object. According to the default naming convention, the function will be named as void new_elementexample(). To define a ElementExample element, one can simply use

element ElementExample !... element definition goes here

The program will look up build-in element library to see if ElementExample exists. If not, it tries to find a function with signature void new_elementexample() in the currently loaded external libraries. If still not found, the program tries to load ElementExample.dll.

If the external library contains more than one function, to use other functions, users need to explicitly import the library.

For CPP implementation, a smart pointer, for example unique_ptr<Element>, is passed from DLL to main executable. It is crucial to ensure both .dll and .exe are compiled with the same configuration. Otherwise, unexpected errors may occur. If possible, always try a C type interface implementation.