source: trunk/abcl/src/org/armedbear/lisp/parse-lambda-list.lisp @ 14196

Last change on this file since 14196 was 11391, checked in by vvoutilainen, 12 years ago

ABCL license is GPL + Classpath exception. This was intended
by Peter Graves, the original author. For reference, see

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1;;; parse-lambda-list.lisp
3;;; Copyright (C) 2003-2005 Peter Graves
4;;; $Id: parse-lambda-list.lisp 11391 2008-11-15 22:38:34Z vvoutilainen $
6;;; This program is free software; you can redistribute it and/or
7;;; modify it under the terms of the GNU General Public License
8;;; as published by the Free Software Foundation; either version 2
9;;; of the License, or (at your option) any later version.
11;;; This program is distributed in the hope that it will be useful,
12;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
14;;; GNU General Public License for more details.
16;;; You should have received a copy of the GNU General Public License
17;;; along with this program; if not, write to the Free Software
18;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20;;; As a special exception, the copyright holders of this library give you
21;;; permission to link this library with independent modules to produce an
22;;; executable, regardless of the license terms of these independent
23;;; modules, and to copy and distribute the resulting executable under
24;;; terms of your choice, provided that you also meet, for each linked
25;;; independent module, the terms and conditions of the license of that
26;;; module.  An independent module is a module which is not derived from
27;;; or based on this library.  If you modify this library, you may extend
28;;; this exception to your version of the library, but you are not
29;;; obligated to do so.  If you do not wish to do so, delete this
30;;; exception statement from your version.
32;;; Adapted from SBCL.
34(in-package "SYSTEM")
36(require '#:collect)
38;;; Break something like a lambda list (but not necessarily actually a
39;;; lambda list, e.g. the representation of argument types which is
40;;; used within an FTYPE specification) into its component parts. We
41;;; return 10 values:
42;;;  1. a list of the required args;
43;;;  2. a list of the &OPTIONAL arg specs;
44;;;  3. true if a &REST arg was specified;
45;;;  4. the &REST arg;
46;;;  5. true if &KEY args are present;
47;;;  6. a list of the &KEY arg specs;
48;;;  7. true if &ALLOW-OTHER-KEYS was specified.;
49;;;  8. true if any &AUX is present (new in SBCL vs. CMU CL);
50;;;  9. a list of the &AUX specifiers;
51;;; 10. true if any lambda list keyword is present (only for
54;;; The top level lambda list syntax is checked for validity, but the
55;;; arg specifiers are just passed through untouched. If something is
56;;; wrong, we signal an error.
58(defun parse-lambda-list-like-thing (list)
59  (collect ((required)
60            (optional)
61            (keys)
62            (aux))
63    (let ((restp nil)
64          (rest nil)
65          (keyp nil)
66    (auxp nil)
67          (allowp nil)
68          (state :required))
69      (declare (type (member :allow-other-keys :aux
70                             :key
71                             :optional
72                             :post-rest
73                             :required :rest)
74                     state))
75      (dolist (arg list)
76        (if (and (symbolp arg)
77                 (let ((name (symbol-name (the symbol arg))))
78                   (and (plusp (length name))
79                        (char= (char name 0) #\&))))
80            (case arg
81              (&optional
82               (unless (eq state :required)
83                 (error "misplaced &OPTIONAL in lambda list: ~S" list))
84               (setq state :optional))
85              (&rest
86               (unless (member state '(:required :optional))
87                 (error "misplaced &REST in lambda list: ~S" list))
88               (setq state :rest))
89              (&key
90               (unless (member state
91                               '(:required :optional :post-rest))
92                 (error "misplaced &KEY in lambda list: ~S" list))
93               (setq keyp t
94                     state :key))
95              (&allow-other-keys
96               (unless (eq state ':key)
97                 (error "misplaced &ALLOW-OTHER-KEYS in lambda list: ~S" list))
98               (setq allowp t
99                     state :allow-other-keys))
100              (&aux
101               (when (eq state :rest)
102                 (error "misplaced &AUX in lambda list: ~S" list))
103               (setq auxp t
104         state :aux))
105              ;; FIXME: I don't think ANSI says this is an error. (It
106              ;; should certainly be good for a STYLE-WARNING,
107              ;; though.)
108              (t
109               (error "unknown &KEYWORD in lambda list: ~S" arg)))
110            (case state
111              (:required (required arg))
112              (:optional (optional arg))
113              (:rest
114               (setq restp t
115                     rest arg
116                     state :post-rest))
117              (:key (keys arg))
118              (:aux (aux arg))
119              (t
120               (error "found garbage in lambda list when expecting a keyword: ~S"
121                      arg)))))
122      (when (eq state :rest)
123        (error "&REST without rest variable"))
125      (values (required) (optional) restp rest keyp (keys) allowp auxp (aux)
126              (neq state :required)))))
128;;; like PARSE-LAMBDA-LIST-LIKE-THING, except our LAMBDA-LIST argument
129;;; really *is* a lambda list, not just a "lambda-list-like thing", so
130;;; can barf on things which're illegal as arguments in lambda lists
131;;; even if they could conceivably be legal in not-quite-a-lambda-list
132;;; weirdosities
133(defun parse-lambda-list (lambda-list)
134  ;; Classify parameters without checking their validity individually.
135  (multiple-value-bind (required optional restp rest keyp keys allowp auxp aux)
136      (parse-lambda-list-like-thing lambda-list)
137    ;; Check validity of parameters.
138    (flet ((need-symbol (x why)
139       (unless (symbolp x)
140         (error "~A is not a symbol: ~S" why x))))
141      (dolist (i required)
142  (need-symbol i "Required argument"))
143      (dolist (i optional)
144  (typecase i
145    (symbol)
146    (cons
147     (destructuring-bind (var &optional init-form supplied-p) i
148       (declare (ignore init-form supplied-p))
149       (need-symbol var "&OPTIONAL parameter name")))
150    (t
151     (error "&OPTIONAL parameter is not a symbol or cons: ~S" i))))
152      (when restp
153  (need-symbol rest "&REST argument"))
154      (when keyp
155  (dolist (i keys)
156    (typecase i
157      (symbol)
158      (cons
159       (destructuring-bind (var-or-kv &optional init-form supplied-p) i
160         (declare (ignore init-form supplied-p))
161         (if (consp var-or-kv)
162       (destructuring-bind (keyword-name var) var-or-kv
163         (declare (ignore keyword-name))
164         (need-symbol var "&KEY parameter name"))
165       (need-symbol var-or-kv "&KEY parameter name"))))
166      (t
167       (error "&KEY parameter is not a symbol or cons: ~S" i))))))
169    ;; Voila.
170    (values required optional restp rest keyp keys allowp auxp aux)))
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