6.2.1.1 The Base

All of these functions are accessed through a single procedure by calling that procedure with the symbol name of the operation. A procedure will be returned if that operation is supported and #f otherwise. For example:

(require 'alist-table)
(define my-base (alist-table 'make-base))
my-base         ⇒ *a procedure*
(define foo (alist-table 'foo))
foo             ⇒ #f

Operation on base-table: make-base filename key-dimension column-types

Returns a new, open, low-level database (collection of tables) associated with filename. This returned database has an empty table associated with catalog-id. The positive integer key-dimension is the number of keys composed to make a primary-key for the catalog table. The list of symbols column-types describes the types of each column for that table. If the database cannot be created as specified, #f is returned.

Calling the close-base method on this database and possibly other operations will cause filename to be written to. If filename is #f a temporary, non-disk based database will be created if such can be supported by the base table implelentation.

Operation on base-table: open-base filename mutable

Returns an open low-level database associated with filename. If mutable is #t, this database will have methods capable of effecting change to the database. If mutable is #f, only methods for inquiring the database will be available. If the database cannot be opened as specified #f is returned.

Calling the close-base (and possibly other) method on a mutable database will cause filename to be written to.

Operation on base-table: write-base lldb filename

Causes the low-level database lldb to be written to filename. If the write is successful, also causes lldb to henceforth be associated with filename. Calling the close-database (and possibly other) method on lldb may cause filename to be written to. If filename is #f this database will be changed to a temporary, non-disk based database if such can be supported by the underlying base table implelentation. If the operations completed successfully, #t is returned. Otherwise, #f is returned.

Operation on base-table: sync-base lldb

Causes the file associated with the low-level database lldb to be updated to reflect its current state. If the associated filename is #f, no action is taken and #f is returned. If this operation completes successfully, #t is returned. Otherwise, #f is returned.

Operation on base-table: close-base lldb

Causes the low-level database lldb to be written to its associated file (if any). If the write is successful, subsequent operations to lldb will signal an error. If the operations complete successfully, #t is returned. Otherwise, #f is returned.