org.armedbear.lisp.parse-lambda-list.lisp Maven / Gradle / Ivy
;;; parse-lambda-list.lisp
;;;
;;; Copyright (C) 2003-2005 Peter Graves
;;; $Id$
;;;
;;; 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
;;; of the License, 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 program; if not, write to the Free Software
;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
;;;
;;; As a special exception, the copyright holders of this library give you
;;; permission to link this library with independent modules to produce an
;;; executable, regardless of the license terms of these independent
;;; modules, and to copy and distribute the resulting executable under
;;; terms of your choice, provided that you also meet, for each linked
;;; independent module, the terms and conditions of the license of that
;;; module. An independent module is a module which is not derived from
;;; or based on this library. If you modify this library, you may extend
;;; this exception to your version of the library, but you are not
;;; obligated to do so. If you do not wish to do so, delete this
;;; exception statement from your version.
;;; Adapted from SBCL.
(in-package "SYSTEM")
(require '#:collect)
;;; Break something like a lambda list (but not necessarily actually a
;;; lambda list, e.g. the representation of argument types which is
;;; used within an FTYPE specification) into its component parts. We
;;; return 10 values:
;;; 1. a list of the required args;
;;; 2. a list of the &OPTIONAL arg specs;
;;; 3. true if a &REST arg was specified;
;;; 4. the &REST arg;
;;; 5. true if &KEY args are present;
;;; 6. a list of the &KEY arg specs;
;;; 7. true if &ALLOW-OTHER-KEYS was specified.;
;;; 8. true if any &AUX is present (new in SBCL vs. CMU CL);
;;; 9. a list of the &AUX specifiers;
;;; 10. true if any lambda list keyword is present (only for
;;; PARSE-LAMBDA-LIST-LIKE-THING).
;;;
;;; The top level lambda list syntax is checked for validity, but the
;;; arg specifiers are just passed through untouched. If something is
;;; wrong, we signal an error.
(defun parse-lambda-list-like-thing (list)
(collect ((required)
(optional)
(keys)
(aux))
(let ((restp nil)
(rest nil)
(keyp nil)
(auxp nil)
(allowp nil)
(state :required))
(declare (type (member :allow-other-keys :aux
:key
:optional
:post-rest
:required :rest)
state))
(dolist (arg list)
(if (and (symbolp arg)
(let ((name (symbol-name (the symbol arg))))
(and (plusp (length name))
(char= (char name 0) #\&))))
(case arg
(&optional
(unless (eq state :required)
(error "misplaced &OPTIONAL in lambda list: ~S" list))
(setq state :optional))
(&rest
(unless (member state '(:required :optional))
(error "misplaced &REST in lambda list: ~S" list))
(setq state :rest))
(&key
(unless (member state
'(:required :optional :post-rest))
(error "misplaced &KEY in lambda list: ~S" list))
(setq keyp t
state :key))
(&allow-other-keys
(unless (eq state ':key)
(error "misplaced &ALLOW-OTHER-KEYS in lambda list: ~S" list))
(setq allowp t
state :allow-other-keys))
(&aux
(when (eq state :rest)
(error "misplaced &AUX in lambda list: ~S" list))
(setq auxp t
state :aux))
;; FIXME: I don't think ANSI says this is an error. (It
;; should certainly be good for a STYLE-WARNING,
;; though.)
(t
(error "unknown &KEYWORD in lambda list: ~S" arg)))
(case state
(:required (required arg))
(:optional (optional arg))
(:rest
(setq restp t
rest arg
state :post-rest))
(:key (keys arg))
(:aux (aux arg))
(t
(error "found garbage in lambda list when expecting a keyword: ~S"
arg)))))
(when (eq state :rest)
(error "&REST without rest variable"))
(values (required) (optional) restp rest keyp (keys) allowp auxp (aux)
(neq state :required)))))
;;; like PARSE-LAMBDA-LIST-LIKE-THING, except our LAMBDA-LIST argument
;;; really *is* a lambda list, not just a "lambda-list-like thing", so
;;; can barf on things which're illegal as arguments in lambda lists
;;; even if they could conceivably be legal in not-quite-a-lambda-list
;;; weirdosities
(defun parse-lambda-list (lambda-list)
;; Classify parameters without checking their validity individually.
(multiple-value-bind (required optional restp rest keyp keys allowp auxp aux)
(parse-lambda-list-like-thing lambda-list)
;; Check validity of parameters.
(flet ((need-symbol (x why)
(unless (symbolp x)
(error "~A is not a symbol: ~S" why x))))
(dolist (i required)
(need-symbol i "Required argument"))
(dolist (i optional)
(typecase i
(symbol)
(cons
(destructuring-bind (var &optional init-form supplied-p) i
(declare (ignore init-form supplied-p))
(need-symbol var "&OPTIONAL parameter name")))
(t
(error "&OPTIONAL parameter is not a symbol or cons: ~S" i))))
(when restp
(need-symbol rest "&REST argument"))
(when keyp
(dolist (i keys)
(typecase i
(symbol)
(cons
(destructuring-bind (var-or-kv &optional init-form supplied-p) i
(declare (ignore init-form supplied-p))
(if (consp var-or-kv)
(destructuring-bind (keyword-name var) var-or-kv
(declare (ignore keyword-name))
(need-symbol var "&KEY parameter name"))
(need-symbol var-or-kv "&KEY parameter name"))))
(t
(error "&KEY parameter is not a symbol or cons: ~S" i))))))
;; Voila.
(values required optional restp rest keyp keys allowp auxp aux)))