external-function operator is used in an external function association inquiry.
In an OmniMark program, an
external-function is a name which is associated with an externally defined (non-OmniMark) function. The external function can have a different name in the external function library than its assigned OmniMark name. An
external-function association inquiry allows the programmer to access the external name of the external-function associated with an OmniMark external function name.
For example, the following code illustrates how
function-library of external-function can be used to query a function and return a string value containing either the external function name or the library name: