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1.5 Catalog Vicinities

Each file in the table below is descibed in terms of its file-system independent vicinity (see Vicinity). The entries of a catalog in the table override those of catalogs above it in the table.

implementation-vicinity slibcat
This file contains the associations for the packages comprising SLIB, the implcat and the sitecats. The associations in the other catalogs override those of the standard catalog.
library-vicinity mklibcat.scm
creates slibcat.
library-vicinity sitecat
This file contains the associations specific to an SLIB installation.
implementation-vicinity implcat
This file contains the associations specific to an implementation of Scheme. Different implementations of Scheme should have different implementation-vicinity.
implementation-vicinity mkimpcat.scm
if present, creates implcat.
implementation-vicinity sitecat
This file contains the associations specific to a Scheme implementation installation.
home-vicinity homecat
This file contains the associations specific to an SLIB user.
user-vicinity usercat
This file contains associations affecting only those sessions whose working directory is user-vicinity.

Here is an example of a usercat catalog. A program in this directory can invoke the ‘run’ feature with (require 'run). 

     ;;; "usercat": SLIB catalog additions for SIMSYNCH.     -*-scheme-*-
     (
      (simsynch      . "../synch/simsynch.scm")
      (run           . "../synch/run.scm")
      (schlep        . "schlep.scm")
     )

Copying usercat to many directories is inconvenient. Application programs which aren't always run in specially prepared directories can nonetheless register their features during initialization.

— Procedure: catalog:read vicinity catalog

Reads file named by string catalog in vicinity, resolving all paths relative to vicinity, and adds those feature associations to *catalog*.

catalog:read would typically be used by an application program having dynamically loadable modules. For instance, to register factoring and other modules in *catalog*, JACAL does: 

          (catalog:read (program-vicinity) "jacalcat")

For an application program there are three appropriate venues for registering its catalog associations: