Dynamic Extensions

A dynamically-linked extension library is loaded into MzScheme with (load-extension file-path). The separate document Inside PLT MzScheme contains information about writing MzScheme extensions. An extension can only be loaded once during a MzScheme session, although the extension-writer can provide functionality to handle extra calls to load-extension for a single extension.

As with load, the current load-relative directory (the value of the current-load-relative-directory parameter; see section 9.4.1.7) is set while the extension is loaded. The load-relative-extension procedure is like load-extension, but it loads an extension with a pathname that is relative to the current load-relative directory instead of the current directory.

The load-extension procedure actually just dispatches to the current load extension handler (see section 9.4.1.7). The result of calling load-extension is determined by the extension. If the extension cannot be loaded, the exn:i/o:filesystem exception is raised. The detail field of the exception is 'wrong-version if the load fails because the extension has the wrong version.