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#| symbol-table.jl -- use modules to provide efficient symbol tables
$Id: symbol-table.jl,v 1.4 2000/07/31 13:40:25 john Exp $
Copyright (C) 2000 John Harper <john@dcs.warwick.ac.uk>
This file is part of librep.
librep is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
librep is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with librep; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|#
;; Commentary:
;; Structures provide the most efficient means of maintaining mappings
;; from symbols to values (tables using eq hashing would be comparable,
;; but less efficient since they're more general).
;; However, I don't want to expose the first-class structure interface
;; to general code, hence these wrappers for making anonymous
;; structures
(define-structure rep.data.symbol-table
(export make-symbol-table
symbol-table-ref
symbol-table-set
symbol-table-boundp
symbol-table-walk)
(open rep
rep.structures)
(define-structure-alias symbol-table rep.data.symbol-table)
(define (make-symbol-table)
(make-structure))
(define (symbol-table-ref table var)
(and (structure-bound-p table var)
(%structure-ref table var)))
(define (symbol-table-set table var value)
(structure-define table var value))
(define (symbol-table-boundp table var)
(structure-bound-p table var))
(define (symbol-table-walk fun table)
(structure-walk fun table)))
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