A.1 Routine Definitions
Routines which can be used
in an IDL program can be defined in several places:
- Builtin routines are defined inside IDL itself.
The source code of such routines is not available, but instead
are learned about through the IDL documentation.
- Routines which are part of the current program,
are defined in a file explicitly compiled by the user. This
file may or may not be located on the IDL search path.
- Library routines are defined in files located on
IDL's search path. When a library routine is called for the
first time, IDL will find the source file and compile it
dynamically. A special sub-category of library routines are the
system routines distributed with IDL, and usually
available in the lib
subdirectory of the IDL distribution.
- External routines written in other languages (like Fortran
or C) can be called with
CALL_EXTERNAL, linked
into IDL via LINKIMAGE, or included as dynamically
loaded modules (DLMs). Currently IDLWAVE cannot provide routine
info and completion for such external routines, except by
querying the Shell for calling information (DLMs only).