--- /dev/null
+;;;; srfi-10.scm --- SRFI-10 read hash extension for Guile
+;;;;
+;;;; Copyright (C) 2001 Free Software Foundation, Inc.
+;;;;
+;;;; This program 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.
+;;;;
+;;;; This program 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 this software; see the file COPYING. If not, write to
+;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+;;;; Boston, MA 02111-1307 USA
+
+;;; Commentary:
+
+;;; This module implements the syntax extension #,(), also called
+;;; hash-comma, which is defined in SRFI-10.
+;;;
+;;; The support for SRFI-10 consists of the procedure
+;;; `define-reader-ctor' for defining new reader constructors and the
+;;; read syntax form
+;;;
+;;; #,(<ctor> <datum> ...)
+;;;
+;;; where <ctor> must be a symbol for which a read constructor was
+;;; defined previously.
+;;;
+;;; Example:
+;;;
+;;; (define-reader-ctor 'file open-input-file)
+;;; (define f '#,(file "/etc/passwd"))
+;;; (read-line f)
+;;; =>
+;;; :root:x:0:0:root:/root:/bin/bash"
+;;;
+;;; Please note the quote before the #,(file ...) expression. This is
+;;; necessary because ports are not self-evaluating in Guile.
+
+;;; Code:
+
+(define-module (srfi srfi-10)
+ #:use-module (ice-9 rdelim))
+
+(export define-reader-ctor)
+
+;; This hash table stores the association between comma-hash tags and
+;; the corresponding constructor procedures.
+;;
+(define reader-ctors (make-hash-table 31))
+
+;; This procedure installs the procedure @var{proc} as the constructor
+;; for the comma-hash tag @var{symbol}.
+;;
+(define (define-reader-ctor symbol proc)
+ (hashq-set! reader-ctors symbol proc)
+ (if #f #f)) ; Return unspecified value.
+
+;; Retrieve the constructor procedure for the tag @var{symbol} or
+;; throw an error if no such tag is defined.
+;;
+(define (lookup symbol)
+ (let ((p (hashq-ref reader-ctors symbol #f)))
+ (if (procedure? p)
+ p
+ (error "unknown hash-comma tag " symbol))))
+
+;; This is the actual reader extension.
+;;
+(define (hash-comma char port)
+ (let* ((obj (read port)))
+ (if (and (list? obj) (positive? (length obj)) (symbol? (car obj)))
+ (let ((p (lookup (car obj))))
+ (let ((res (apply p (cdr obj))))
+ res))
+ (error "syntax error in hash-comma expression"))))
+
+;; Install the hash extension.
+;;
+(read-hash-extend #\, hash-comma)
--- /dev/null
+;;;; srfi-17.scm --- SRFI-17 procedures for Guile
+
+;;; Copyright (C) 2001 Free Software Foundation, Inc.
+;;; Originally by Matthias Koeppe <mkoeppe@mail.math.uni-magdeburg.de>
+;;;
+;;; This program 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.
+;;;
+;;; This program 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 this software; see the file COPYING. If not, write to
+;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+;;; Boston, MA 02111-1307 USA
+
+;;; Commentary:
+
+;; This is an implementation of SRFI-17: Generalized set!
+;;
+;; It exports the Guile procedure `make-procedure-with-setter' under
+;; the SRFI name `getter-with-setter' and exports the standard
+;; procedures `car', `cdr', ..., `cdddr', `string-ref' and
+;; `vector-ref' as procedures with setters, as required by the SRFI.
+;;
+;; SRFI-17 was heavily criticized during its discussion period but it
+;; was finalized anyway. One issue was its concept of globally
+;; associating setter "properties" with (procedure) values, which is
+;; non-Schemy. For this reason, this implementation chooses not to
+;; provide a way to set the setter of a procedure. In fact, (set!
+;; (setter PROC) SETTER) signals an error. The only way to attach a
+;; setter to a procedure is to create a new object (a "procedure with
+;; setter") via the `getter-with-setter' procedure. This procedure is
+;; also specified in the SRFI. Using it avoids the described
+;; problems.
+
+;;; Code:
+
+(define-module (srfi srfi-17)
+ :export (getter-with-setter
+ setter
+ ;; redefined standard procedures
+ car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar
+ cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr
+ caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr
+ cdddar cddddr string-ref vector-ref))
+
+;;; Procedures
+
+(define getter-with-setter make-procedure-with-setter)
+
+(define setter
+ (getter-with-setter
+ setter
+ (lambda args
+ (error "Setting setters is not supported for a good reason."))))
+
+;;; Redefine R5RS procedures to appropriate procedures with setters
+
+(define (compose-setter setter location)
+ (lambda (obj value)
+ (setter (location obj) value)))
+
+(define car (getter-with-setter car set-car!))
+(define cdr (getter-with-setter cdr set-cdr!))
+(define caar (getter-with-setter caar (compose-setter set-car! car)))
+(define cadr (getter-with-setter cadr (compose-setter set-car! cdr)))
+(define cdar (getter-with-setter cdar (compose-setter set-cdr! car)))
+(define cddr (getter-with-setter cddr (compose-setter set-cdr! cdr)))
+(define caaar (getter-with-setter caaar (compose-setter set-car! caar)))
+(define caadr (getter-with-setter caadr (compose-setter set-car! cadr)))
+(define cadar (getter-with-setter cadar (compose-setter set-car! cdar)))
+(define caddr (getter-with-setter caddr (compose-setter set-car! cddr)))
+(define cdaar (getter-with-setter cdaar (compose-setter set-cdr! caar)))
+(define cdadr (getter-with-setter cdadr (compose-setter set-cdr! cadr)))
+(define cddar (getter-with-setter cddar (compose-setter set-cdr! cdar)))
+(define cdddr (getter-with-setter cdddr (compose-setter set-cdr! cddr)))
+(define caaaar (getter-with-setter caaaar (compose-setter set-car! caaar)))
+(define caaadr (getter-with-setter caaadr (compose-setter set-car! caadr)))
+(define caadar (getter-with-setter caadar (compose-setter set-car! cadar)))
+(define caaddr (getter-with-setter caaddr (compose-setter set-car! caddr)))
+(define cadaar (getter-with-setter cadaar (compose-setter set-car! cdaar)))
+(define cadadr (getter-with-setter cadadr (compose-setter set-car! cdadr)))
+(define caddar (getter-with-setter caddar (compose-setter set-car! cddar)))
+(define cadddr (getter-with-setter cadddr (compose-setter set-car! cdddr)))
+(define cdaaar (getter-with-setter cdaaar (compose-setter set-cdr! caaar)))
+(define cdaadr (getter-with-setter cdaadr (compose-setter set-cdr! caadr)))
+(define cdadar (getter-with-setter cdadar (compose-setter set-cdr! cadar)))
+(define cdaddr (getter-with-setter cdaddr (compose-setter set-cdr! caddr)))
+(define cddaar (getter-with-setter cddaar (compose-setter set-cdr! cdaar)))
+(define cddadr (getter-with-setter cddadr (compose-setter set-cdr! cdadr)))
+(define cdddar (getter-with-setter cdddar (compose-setter set-cdr! cddar)))
+(define cddddr (getter-with-setter cddddr (compose-setter set-cdr! cdddr)))
+(define string-ref (getter-with-setter string-ref string-set!))
+(define vector-ref (getter-with-setter vector-ref vector-set!))
HCoop / bpt / guile.git / commitdiff