utils.lisp

;;;;
;;;; Copyright (c) 2008 - 2009 Tobias C. Rittweiler <tcr@freebits.de>
;;;;
;;;; All rights reserved.
;;;;
;;;; See LICENSE for details.
;;;;

(in-package :editor-hints.named-readtables)

(defmacro without-package-lock ((&rest package-names) &body body)
  (declare (ignorable package-names))
  #+clisp
  (return-from without-package-lock
    `(ext:without-package-lock (,@package-names) ,@body))
  #+lispworks
  (return-from without-package-lock
    `(let ((hcl:*packages-for-warn-on-redefinition*
            (set-difference hcl:*packages-for-warn-on-redefinition*
                            '(,@package-names)
                            :key (lambda (package-designator)
                                   (if (packagep package-designator)
                                       (package-name package-designator)
                                       package-designator))
                            :test #'string=)))
       ,@body))
  `(progn ,@body))

;;; Taken from SWANK (which is Public Domain.)

(defmacro destructure-case (value &rest patterns)
  "Dispatch VALUE to one of PATTERNS.
A cross between `case' and `destructuring-bind'.
The pattern syntax is:
  ((HEAD . ARGS) . BODY)
The list of patterns is searched for a HEAD `eq' to the car of
VALUE. If one is found, the BODY is executed with ARGS bound to the
corresponding values in the CDR of VALUE."
  (let ((operator (gensym "op-"))
        (operands (gensym "rand-"))
        (tmp (gensym "tmp-")))
    `(let* ((,tmp ,value)
            (,operator (car ,tmp))
            (,operands (cdr ,tmp)))
       (case ,operator
         ,@(loop for (pattern . body) in patterns collect
                   (if (eq pattern t)
                       `(t ,@body)
                       (destructuring-bind (op &rest rands) pattern
                         `(,op (destructuring-bind ,rands ,operands
                                 ,@body)))))
         ,@(if (eq (caar (last patterns)) t)
               '()
               `((t (error "destructure-case failed: ~S" ,tmp))))))))

;;; Taken from Alexandria (which is Public Domain, or BSD.)

(define-condition simple-style-warning (simple-warning style-warning)
  ())

(defun simple-style-warn (format-control &rest format-args)
  (warn 'simple-style-warning
	 :format-control format-control
	 :format-arguments format-args))

(define-condition simple-program-error (simple-error program-error)
  ())

(defun simple-program-error (message &rest args)
  (error 'simple-program-error
         :format-control message
         :format-arguments args))

(defun required-argument (&optional name)
  "Signals an error for a missing argument of NAME. Intended for
use as an initialization form for structure and class-slots, and
a default value for required keyword arguments."
  (error "Required argument ~@[~S ~]missing." name))

(defun ensure-list (list)
  "If LIST is a list, it is returned. Otherwise returns the list
designated by LIST."
  (if (listp list)
      list
      (list list)))

(declaim (inline ensure-function))	; to propagate return type.
(declaim (ftype (function (t) (values function &optional))
                ensure-function))
(defun ensure-function (function-designator)
  "Returns the function designated by FUNCTION-DESIGNATOR:
if FUNCTION-DESIGNATOR is a function, it is returned, otherwise
it must be a function name and its FDEFINITION is returned."
  (if (functionp function-designator)
      function-designator
      (fdefinition function-designator)))

(defun parse-body (body &key documentation whole)
  "Parses BODY into (values remaining-forms declarations doc-string).
Documentation strings are recognized only if DOCUMENTATION is true.
Syntax errors in body are signalled and WHOLE is used in the signal
arguments when given."
  (let ((doc nil)
        (decls nil)
        (current nil))
    (tagbody
     :declarations
       (setf current (car body))
       (when (and documentation (stringp current) (cdr body))
         (if doc
             (error "Too many documentation strings in ~S." (or whole body))
             (setf doc (pop body)))
         (go :declarations))
       (when (and (listp current) (eql (first current) 'declare))
         (push (pop body) decls)
         (go :declarations)))
    (values body (nreverse decls) doc)))

(defun parse-ordinary-lambda-list (lambda-list)
  "Parses an ordinary lambda-list, returning as multiple values:

 1. Required parameters.
 2. Optional parameter specifications, normalized into form (NAME INIT SUPPLIEDP)
    where SUPPLIEDP is NIL if not present.
 3. Name of the rest parameter, or NIL.
 4. Keyword parameter specifications, normalized into form ((KEYWORD-NAME NAME) INIT SUPPLIEDP)
    where SUPPLIEDP is NIL if not present.
 5. Boolean indicating &ALLOW-OTHER-KEYS presence.
 6. &AUX parameter specifications, normalized into form (NAME INIT).

Signals a PROGRAM-ERROR is the lambda-list is malformed."
  (let ((state :required)
        (allow-other-keys nil)
        (auxp nil)
        (required nil)
        (optional nil)
        (rest nil)
        (keys nil)
        (aux nil))
    (labels ((simple-program-error (format-string &rest format-args)
               (error 'simple-program-error
                      :format-control format-string
                      :format-arguments format-args))
             (fail (elt)
               (simple-program-error "Misplaced ~S in ordinary lambda-list:~%  ~S"
                                     elt lambda-list))
             (check-variable (elt what)
               (unless (and (symbolp elt) (not (constantp elt)))
                 (simple-program-error "Invalid ~A ~S in ordinary lambda-list:~%  ~S"
                                       what elt lambda-list)))
             (check-spec (spec what)
               (destructuring-bind (init suppliedp) spec
                 (declare (ignore init))
                 (check-variable suppliedp what)))
             (make-keyword (name)
               "Interns the string designated by NAME in the KEYWORD package."
               (intern (string name) :keyword)))
      (dolist (elt lambda-list)
        (case elt
          (&optional
           (if (eq state :required)
               (setf state elt)
               (fail elt)))
          (&rest
           (if (member state '(:required &optional))
               (setf state elt)
               (progn
                 (break "state=~S" state)
                 (fail elt))))
          (&key
           (if (member state '(:required &optional :after-rest))
               (setf state elt)
               (fail elt)))
          (&allow-other-keys
           (if (eq state '&key)
               (setf allow-other-keys t
                     state elt)
               (fail elt)))
          (&aux
           (cond ((eq state '&rest)
                  (fail elt))
                 (auxp
                  (simple-program-error "Multiple ~S in ordinary lambda-list:~%  ~S"
                                        elt lambda-list))
                 (t
                  (setf auxp t
                        state elt))
                 ))
          (otherwise
           (when (member elt '#.(set-difference lambda-list-keywords
                                                '(&optional &rest &key &allow-other-keys &aux)))
             (simple-program-error
              "Bad lambda-list keyword ~S in ordinary lambda-list:~%  ~S"
              elt lambda-list))
           (case state
             (:required
              (check-variable elt "required parameter")
              (push elt required))
             (&optional
              (cond ((consp elt)
                     (destructuring-bind (name &rest tail) elt
                       (check-variable name "optional parameter")
                       (if (cdr tail)
                           (check-spec tail "optional-supplied-p parameter")
                           (setf elt (append elt '(nil))))))
                    (t
                     (check-variable elt "optional parameter")
                     (setf elt (cons elt '(nil nil)))))
              (push elt optional))
             (&rest
              (check-variable elt "rest parameter")
              (setf rest elt
                    state :after-rest))
             (&key
              (cond ((consp elt)
                     (destructuring-bind (var-or-kv &rest tail) elt
                       (cond ((consp var-or-kv)
                              (destructuring-bind (keyword var) var-or-kv
                                (unless (symbolp keyword)
                                  (simple-program-error "Invalid keyword name ~S in ordinary ~
                                                         lambda-list:~%  ~S"
                                                        keyword lambda-list))
                                (check-variable var "keyword parameter")))
                             (t
                              (check-variable var-or-kv "keyword parameter")
                              (setf var-or-kv (list (make-keyword var-or-kv) var-or-kv))))
                       (if (cdr tail)
                           (check-spec tail "keyword-supplied-p parameter")
                           (setf tail (append tail '(nil))))
                       (setf elt (cons var-or-kv tail))))
                    (t
                     (check-variable elt "keyword parameter")
                     (setf elt (list (list (make-keyword elt) elt) nil nil))))
              (push elt keys))
             (&aux
              (if (consp elt)
                  (destructuring-bind (var &optional init) elt
                    (declare (ignore init))
                    (check-variable var "&aux parameter"))
                  (check-variable elt "&aux parameter"))
              (push elt aux))
             (t
              (simple-program-error "Invalid ordinary lambda-list:~%  ~S" lambda-list)))))))
    (values (nreverse required) (nreverse optional) rest (nreverse keys)
            allow-other-keys (nreverse aux))))