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Revision 12 - (show annotations)
Mon Dec 31 13:39:29 2012 UTC (15 months, 2 weeks ago) by rklochkov
File size: 15801 byte(s)
Fixed wrong behavior when no symbol found
1 (in-package #:advanced-readtable)
2
3 ;;;; Advanced-readtable
4 ;;;;
5 ;;;; per-package aliases for packages
6 ;;;; per-package shortcuts for package hierarchies
7 ;;;; extendable find-package and find-symbol
8 ;;;; local use package in form package:(here form where package used)
9 ;;;; local intern package like in SBCL: package::(symbol1 symbol2) will intern
10 ;;;; package::symbol1 and package::symbol2
11
12 (defvar *per-package-finders* (make-hash-table :test 'eq)
13 "Hash package -> list of handlers. Each handler is a cons (key . function)")
14 (defvar *package-finders* nil
15 "List of handlers. Each handler is a cons (key . function)
16 function = (lambda (name package) ...) -> package")
17
18 ;;;
19 ;;; Prepare readtables
20 ;;;
21
22 (defvar *advanced-readtable* (copy-readtable nil))
23 (defvar *colon-readtable* (copy-readtable nil)
24 "Support readtable with colon as whitespace")
25
26 ;;;
27 ;;; Readtable handlers
28 ;;;
29
30 (defpackage #:advanced-readtable.junk)
31
32 (defun try-funcall (handlers-list name package)
33 (declare (type list handlers-list)
34 (type string name)
35 (type (or null package) package))
36 (when handlers-list
37 (or (funcall (cdr (car handlers-list)) name package)
38 (try-funcall (cdr handlers-list) name package))))
39
40 (defun find-package (name &optional (current-package *package*))
41 "We try to find package.
42 1. By full name with CL:FIND-PACKAGE.
43 2. By per-package handlers. Here we wil try local-nicknames and so on.
44 3. By global handlers. Here we may use, for example, hierarchical packages."
45 (declare (type (or null package) current-package))
46 (if (typep name 'package) name
47 (let ((sname (string name)))
48 (or
49 (cl:find-package name)
50 (when current-package
51 (try-funcall (package-finders current-package)
52 sname current-package))
53 (try-funcall *package-finders* sname current-package)))))
54
55 (defvar *package-symbol-finders* (make-hash-table :test 'eq)
56 "Hash package -> list of handlers. Each handler is a cons (key . function)")
57 (defvar *symbol-finders* nil
58 "List of handlers. Each handler is a cons (key . function)
59 function = (lambda (name package) ...) -> symbol")
60 (defvar *extra-finders* (make-hash-table :test 'eq)
61 "Hash symbol -> list of handlers. Each handler is a cons (key . function)
62 function = (lambda (name package) ...) -> symbol
63 These will be used before CL:FIND-SYMBOL")
64
65 (defvar *symbol-readmacros* (make-hash-table :test 'eq))
66 (defvar *disable-symbol-readmacro* nil
67 "Disables processing of symbol-readmacro.")
68
69 (defun def-symbol-readmacro (symbol func)
70 (setf (gethash symbol *symbol-readmacros*) func))
71
72 (defun set-macro-symbol (symbol func)
73 "Syntax is like set-macro-character,
74 except that FUNC is binded to SYMBOL, not character"
75 (setf (gethash symbol *symbol-readmacros*) func))
76
77 (defun get-macro-symbol (symbol)
78 "Syntax is like get-macro-character.
79 Returns function, assigned by set-macro-symbol"
80 (gethash symbol *symbol-readmacros*))
81
82 (defun process-symbol-readmacro (symbol stream)
83 (let ((func (gethash symbol *symbol-readmacros*)))
84 (if func (funcall func stream symbol) symbol)))
85
86 ;;; Internal special variables. Do not export
87
88 (defvar *extra-symbol-finders* nil
89 "List of handlers: handlers for symbol, car of list")
90 (defvar *car-list* nil "Boolean: iff reader in list and car is not read")
91 (defvar *local-packages* nil "List of packages: for pack:( ... pack2:(...))")
92
93 (defun try-local-packages (packages name)
94 (when packages
95 (multiple-value-bind (symbol status) (cl:find-symbol name (car packages))
96 (if symbol
97 (values symbol status)
98 (try-local-packages (cdr packages) name)))))
99
100 (defun try-mv-funcall (handlers-list name package)
101 "Returns symbol, status"
102 (declare (type list handlers-list)
103 (type string name)
104 (type (or null package) package))
105 (when handlers-list
106 (multiple-value-bind (symbol status)
107 (funcall (cdr (car handlers-list)) name package)
108 (if symbol
109 (values symbol status)
110 (try-funcall (cdr handlers-list) name package)))))
111
112
113 (defun find-symbol (name &optional dpackage)
114 "We try to find symbol
115 1. In package set with car of list, for example, PUSH-LOCAL-PACKAGE
116 2. By CL-FIND-SYMBOL, when package explicitly given
117 3. By packages added with package:(...)
118 4. By per-package finders
119 5. By global finders
120 6. By CL-FIND-SYMBOL"
121 (declare (type string name))
122 (let ((package (if dpackage (find-package dpackage) *package*)))
123 (macrolet ((mv-or (&rest clauses)
124 (if clauses
125 `(multiple-value-bind (symbol status) ,(car clauses)
126 (if symbol (values symbol status)
127 (mv-or . ,(cdr clauses))))
128 `(values nil nil))))
129
130 (mv-or
131 (try-mv-funcall *extra-symbol-finders* name package)
132 (when dpackage (cl:find-symbol name package))
133 (unless dpackage (try-local-packages *local-packages* name))
134 (try-mv-funcall (symbol-finders package) name package)
135 (try-mv-funcall *symbol-finders* name package)
136 (unless dpackage (cl:find-symbol name package))))))
137
138 (defun read-token (stream)
139 "
140 DO: Reads from STREAM a symbol or number up to whitespace or colon
141 RETURN: symbols name or numbers value"
142 (let ((*readtable* *colon-readtable*)
143 (*package* (cl:find-package '#:advanced-readtable.junk)))
144 (read-preserving-whitespace stream nil)))
145
146 (defun count-colons (stream)
147 "
148 DO: Reads colons from STREAM
149 RETURN: number of the colons"
150 (let ((c (read-char stream nil)))
151 (if (eql c #\:)
152 (+ 1 (count-colons stream))
153 (progn (unread-char c stream) 0))))
154
155 (defun read-after-colon (stream maybe-package colons)
156 "Read symbol package:sym or list package:(...)"
157 (declare (type stream stream)
158 (type (integer 0 2) colons))
159 (check-type colons (integer 0 2))
160 (when (= colons 0) ; no colon: this is a symbol or an atom
161 (return-from read-after-colon
162 (if (symbolp maybe-package)
163 (prog1
164 (let ((name (symbol-name maybe-package)))
165 (or (find-symbol name) (intern name)))
166 (unintern maybe-package))
167 maybe-package)))
168
169 (let ((package (find-package maybe-package)))
170 (assert package (package) "No package ~a" maybe-package)
171 (unintern maybe-package)
172 (when (eql (peek-char t stream) #\()
173 ;; package:(...) or package::(...)
174 (ecase colons
175 (1 (let ((*local-packages* (cons package *local-packages*)))
176 (return-from read-after-colon
177 (read stream nil))))
178 (2 (let ((*package* package))
179 (return-from read-after-colon
180 (read stream nil))))))
181
182 (let ((token (read-token stream)))
183 (check-type token symbol)
184 (multiple-value-bind (symbol status)
185 (find-symbol (symbol-name token) package)
186 (unless status
187 (if (= colons 1) (error "No external symbol ~S in ~S"
188 (symbol-name token) package)
189 (cerror "Intern ~S in ~S" "No such symbol ~S in package ~S"
190 (symbol-name token) package)))
191 (unintern token)
192 (when (and (= colons 1) (not (eq status :external)))
193 (cerror "Use anyway"
194 "Symbol ~A not external" symbol))
195 symbol))))
196
197
198
199 (defun read-token-with-colons (stream char)
200 "Reads token, then analize package part if needed"
201 (unread-char char stream)
202 (when *read-suppress*
203 (let ((*readtable* (copy-readtable nil)))
204 (read stream))
205 (return-from read-token-with-colons))
206 (let* ((token (read-token stream))
207 ;; We have read something.
208 ;; It may represent either symbol or package designator.
209 ;; Looking after it: do we have a colon?
210 (colons (count-colons stream))
211 (object (read-after-colon stream token colons)))
212
213 (when (or *disable-symbol-readmacro*
214 (not (symbolp object))
215 (eql char #\|))
216 (return-from read-token-with-colons object))
217
218 (let ((object (process-symbol-readmacro object stream)))
219 (when *car-list*
220 (setf *car-list* nil
221 *extra-symbol-finders*
222 (append (extra-finders object) *extra-symbol-finders*)))
223 object)))
224
225 (let ((default-open-paren-reader
226 (get-macro-character #\( (copy-readtable nil))))
227 (defun open-paren-reader (stream char)
228 (let ((*car-list* t) (*extra-symbol-finders* *extra-symbol-finders*))
229 (funcall default-open-paren-reader stream char))))
230
231
232
233 (defun (setf package-finders) (value &optional (package *package*))
234 (setf (gethash (find-package package) *per-package-finders*) value))
235
236 (defun package-finders (&optional (package *package*))
237 (gethash (find-package package) *per-package-finders*))
238
239 (defun (setf symbol-finders) (value &optional (package *package*))
240 (setf (gethash (find-package package) *package-symbol-finders*) value))
241
242 (defun symbol-finders (&optional (package *package*))
243 (gethash (find-package package) *package-symbol-finders*))
244
245 (defun (setf extra-finders) (value symbol)
246 (setf (gethash symbol *extra-finders*) value))
247
248 (defun extra-finders (symbol)
249 (gethash symbol *extra-finders*))
250
251 (defmacro set-handler (handler-list key function)
252 "This is middle-level public API for changing handlers for
253 find-symbol and find-package. There are five lists:
254 *package-finders* -- global for find-package
255 *symbol-finders* -- global for find-symbol
256 (package-finders package) -- per-package for find-package
257 (symbol-finders package) -- per-package for find-symbol
258 (extra-finders symbol) -- per-symbol for (symbol ....) package substitution
259
260 Key should be uniq in the sense of EQUAL in the list. SET-HANDLER adds
261 new handler if it is not already there.
262 "
263 (let ((key-var (gensym "key")))
264 `(let ((,key-var ,key))
265 (unless (assoc ,key-var ,handler-list :test #'equal)
266 (push (cons ,key-var ,function)
267 ,handler-list)))))
268
269 (defmacro %set-handler (handler-list key name &body handler-body)
270 "Local macros for push-* functions. No gensyms intended."
271 `(set-handler ,handler-list ,key
272 (lambda (,name package)
273 (declare (ignore package)) . ,handler-body)))
274
275 (defun push-import-prefix (prefix &optional (package *package*))
276 "Enables using package name omitting prefix.
277 For example, you have packages com.clearly-useful.iterator-protocol, com.clearly-useful.reducers, ...
278 You may use them as
279 (push-import-prefix :com.clearly-useful)
280 (iterator-protocol:do-iterator ...)
281 (reducers:r/map #'1+ data)
282 and so on.
283 Package prefix is enabled per package so it is safe to use it in your package.
284
285 If there is package, which name coincides with shortcut, package name has priority.
286
287 So, if you make
288 (defpackage :reducers ...)
289
290 after that reducers:... will refer to new package, not com.clearly-useful.reducers.
291 "
292 (%set-handler (package-finders package) `(:prefix ,prefix) name
293 (cl:find-package (concatenate 'string (string prefix) "." name))))
294
295 (defun push-local-nickname (long-package nick
296 &optional (current-package *package*))
297 "Enables package nickname in CURRENT-PACKAGE.
298 For example, you found COM.INFORMATIMAGO.COMMON-LISP.CESARUM.LIST package and want to use
299 it. But don't want to USE-PACKAGE them, because some exported symbols from it are clashing
300 with yours.
301
302 You may do it right:
303 (push-local-nickname :com.informatimago.common-lisp.cesarum.list :ilist)
304 (ilist:circular-length l)
305
306 Local-nicknames are local, so you may use it freely.
307
308 If package A wants package LIB version 1, and package B wants package
309 LIB version 2, one can simply rename LIB version 1 to LIB1 and rename LIB
310 version 2 to LIB2 and make
311 (push-local-nickname :lib1 :lib :a)
312 (push-local-nickname :lib2 :lib :b)
313 "
314 (let ((dpackage (find-package long-package)))
315 (%set-handler (package-finders current-package) `(:nick ,long-package ,nick) name
316 (when (string= name (string nick)) dpackage))))
317
318 (defun push-local-package (symbol local-package)
319 "Sets local-package for a symbol. Many macroses use there own clauses.
320 For example, ITERATE uses FOR, COLLECT and so on.
321 If you don't want to USE-PACKAGE iterate, this function will help.
322 (push-local-package 'iter:iter :iterate)
323 (iter:iter (for i from 1 to 10) (collect i))
324
325 Caution: this function enables package substitution in all cases,
326 where SYMBOL is the car of a list.
327 For example, this will be error:
328 (let (iter:iter for) (list iter:iter for))
329 , because first for is in ITERATE package, but second -- is not.
330 "
331 (let ((dpackage (find-package local-package)))
332 (%set-handler (extra-finders symbol) `(:local ,symbol ,local-package) name
333 (multiple-value-bind (symbol status) (cl:find-symbol name dpackage)
334 (when (eq status :external) symbol)))))
335
336 ;;;
337 ;;; Readtable analysis and change
338 ;;;
339
340 (defmacro with-case (case &body body)
341 (let ((save (gensym)))
342 `(let ((,save (readtable-case *readtable*)))
343 (setf (readtable-case *readtable*) ,case)
344 (unwind-protect
345 (progn ,@body)
346 (setf (readtable-case *readtable*) ,save)))))
347
348 (defun does-not-terminate-token-p (c)
349 (ignore-errors
350 (let ((str (format nil "a~Ab" c)))
351 (string= str (symbol-name
352 (with-case :preserve
353 (read-from-string (format nil "#:~A" str))))))))
354
355
356 (defun whitespace-p (c)
357 (ignore-errors
358 (= 2 (length (read-from-string (format nil "(#:a~A#:b)" c))))))
359
360 (defun multiple-escape-p (c)
361 (ignore-errors
362 (string= "qQ" (symbol-name
363 (with-case :upcase
364 (read-from-string (format nil "#:~AqQ~A" c c)))))))
365
366 (defun single-escape-p (c)
367 (ignore-errors
368 (string= (symbol-name '#:\ ) (symbol-name
369 (read-from-string (format nil "#:~A'" c))))))
370
371
372
373 (defun macro-char-p (c)
374 "If C is macro-char, return GET-MACRO-CHARACTER"
375 #+allegro (unless
376 (eql (get-macro-character c) #'excl::read-token)
377 (get-macro-character c))
378 #-allegro (get-macro-character c))
379
380 (defun fill-char-table ()
381 "Returns simple-vector with character syntax classes"
382 (let ((*readtable* (copy-readtable nil))
383 (char-table (make-array 127)))
384 (dotimes (i (length char-table))
385 (let ((c (code-char i)))
386 (setf
387 (svref char-table i)
388 (cond
389 ((eql c #\:) :colon)
390 ((macro-char-p c) :macro)
391 ((does-not-terminate-token-p c) :does-not-terminate-token)
392 ((whitespace-p c) :whitespace)
393 ((multiple-escape-p c) :multiple-escape)
394 ((single-escape-p c) :single-escape)))))
395 char-table))
396
397 (let (initialized)
398 (defun activate (&optional force)
399 "Inits *advanced-readtable* and *colon-readtable*."
400 (when (or force (not initialized))
401 (setq initialized t)
402 (let ((char-table (fill-char-table)))
403 (dotimes (i (length char-table))
404 (let ((b (svref char-table i))
405 (c (code-char i)))
406 (unless (char= #\# c)
407 (when (member b '(:does-not-terminate-token
408 :multiple-escape :single-escape))
409 ;; will make it non-terminating macro character
410 ;; = potentially beginning of the package-name
411 (set-macro-character c #'read-token-with-colons
412 t *advanced-readtable*))))))
413
414 (set-syntax-from-char #\: #\Space *colon-readtable* *colon-readtable*)
415 (set-macro-character #\( #'open-paren-reader nil *advanced-readtable*))
416 (setf *readtable* *advanced-readtable*)))
417
418 (defun ! () (activate))

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