Catalogs are files containing scanned information on individual routines, including arguments and keywords, calling sequence, file path, class and procedure vs. function type, etc. They represent a way of extending the internal built-in information available for IDL system routines (see Routine Info) to other source collections.
Starting with version 5.0, there are two types of catalogs available with IDLWAVE. The traditional user catalog and the newer library catalogs. Although they can be used interchangeably, the library catalogs are more flexible, and preferred. There are few occasions when a user catalog might be preferred—read below. Both types of catalogs can coexist without causing problems.
To facilitate the catalog systems, IDLWAVE stores information it gathers
from the shell about the IDL search paths, and can write this
information out automatically, or on-demand (menu Debug->Save Path
Info). On systems with no shell from which to discover the path
information (e.g., Windows), a library path must be specified in
idlwave-library-path to allow library catalogs to be located, and
to setup directories for user catalog scan (see User Catalog for
more on this variable). Note that, before the shell is running, IDLWAVE
can only know about the IDL search path by consulting the file pointed
to by idlwave-path-file (~/.emacs.d/idlwave/idlpath.el, by
default). If idlwave-auto-write-path is enabled (which is the
default), the paths are written out whenever the IDLWAVE shell is
started.
t) ¶Write out information on the !PATH and !DIR paths from IDL automatically when they change and when the Shell is closed. These paths are needed to locate library catalogs.
IDL library path for Windows and macOS. Under Unix/macOS, will be obtained from the Shell when run.
The IDL system directory for Windows and macOS. Also needed for locating HTML help and the IDL Assistant for IDL v6.2 and later. Under Unix/macOS, will be obtained from the Shell and recorded, if run.
Default path where IDLWAVE saves configuration information, a user catalog (if any), and a cached scan of the XML catalog (IDL v6.2 and later).