Howdy List,
I was having problems when using iterate with the arnesi call/cc
codewalker, because variables bound by iterate were not in the
environment of any macros in an iterate body form. The codewalker
therefore gets that foo is an unbound variable in the iter clause
below.
To mitigate this, I patched iterate to update the *env*
variable to reflect any bindings that iterate is going to make (in
sbcl only ATM). Pulling some code from (bsd licenced)
http://common-lisp.net/project/bese/repos/arnesi_dev/src/lexenv.lisp,
I could probably write an implementation of the two methods I added in
all the arnesi supported environments (lispworks /clisp /allegro
/cmucl), but I have no way of testing these, so for now I stuck with a
tested implementation for sbcl.
The semantics of this are fairly straightforward, in that any variable
declared textually before a macro call will appear as a lexical
variable in the environment passed to the macroexpansion.
(loop for foo upfrom 0
while (= foo 0)
collect (funcall (lambda ()
(arnesi:with-call/cc
foo))))
=> (0)
(iter (for foo upfrom 0)
(while (= foo 0))
(collect (funcall (lambda ()
(arnesi:with-call/cc
foo)))))
=> Before my patch this throws unbound variable foo exception /
lexical environment is empty
After my patch this "correctly" returns (0)
Cheers,
Russ
New patches:
[update environment with iterate produced variables
Russ Tyndall <r...@acceleration.net>**20090520185521
Iterate produces variable bindings that are useful/necessary to macros
expanding inside
of an iterate body. This particularly effects other codewalkers (such as
arnesi).
We want (if possible) to update the env we expand macros in to reflect any
variables
that iterate is lexically binding.
] {
hunk ./iterate.lisp 655
+(defgeneric lexical-variables (environment)
+ (:documentation "Return the names of all the local variables
+ in ENVIRONMENT. Does not return neither symbol-macrolets nor
+ ignared variables.")
+ (:method ((env T)) ()))
+
+#+sbcl
+(defmethod lexical-variables ((environment sb-kernel:lexenv))
+ (loop for var-spec in (sb-c::lexenv-vars environment)
+ when (and (atom (cdr var-spec))
+ (not (and (typep (cdr var-spec) 'sb-c::lambda-var)
+ (sb-c::lambda-var-ignorep (cdr var-spec)))))
+ collect (car var-spec)))
+
+(defgeneric update-environment (env)
+ (:method ((env T)) env)
+ (:documentation "Updates the lexical environment to reflect all of the
available
+ bindings that iterate has thus far created "))
+
+#+sbcl
+(defmethod update-environment ((env sb-kernel:lexenv))
+ (let ((new-bindings
+ (loop for (sym . _) in *bindings*
+ unless (or (null (symbol-package sym))
+ (find sym (lexical-variables *env*)))
+ collect (cons sym T))))
+ (sb-c::make-lexenv :default env :vars new-bindings)))
+
hunk ./iterate.lisp 709
+
+ ;; Iterate produces variable bindings that are useful/necessary to
macros expanding inside
+ ;; of an iterate body. This particularly effects other codewalkers
(such as arnesi).
+ ;; We want (if possible) to update our environment to reflect any
variables that
+ ;; iterate is lexically binding
+ (setf *env* (update-environment *env*))
+
}
Context:
[first-time-p bugfix: return-code :body must return list of forms
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070525141533
if-first-time not declared obsolete
documentation strings for (iter:display-iterate-clauses) complete
]
[fix defmacro-driver example in manual
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070525081443]
[Use @:, @. and two spaces between sentences
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070525080932
Move section on predicate (first-time-p) outside of gathering clauses
Various typos and some clarifications
]
[document *list-end-test* removal in FOR...IN+ON
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070525074338]
[Renamed back to sharpL-reader
attila.lend...@gmail.com**20070506100744]
[Fix sharpL reader, add :execute to the eval-when to make (load "iterate"
:compiling t) work on clisp
attila.lend...@gmail.com**20070506100704]
[Convert manual to Texinfo.
Luis Oliveira <lolive...@common-lisp.net>**20060713142915]
[make FOR...IN/ON with dotted lists work like LOOP
hoe...@users.sourceforge.net**20070503130604
More precisely, FOR ON accepts dotted lists, FOR IN errors out.
As a result, iterate::*list-end-test* was eliminated.
Behaviour is now constant and does not depend on some special variable.
Note: Documentation not yet updated, pending move to Texinfo.
]
[walk-tagbody: more testcases
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070503095309]
[walk-tagbody must not macroexpand symbol/tags among its statements
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070404124132]
[add ELSE test cases, remove GNU Arch tag
Joerg-Cyril Hoehle <hoe...@users.sourceforge.net>**20070503093008]
[Clean up #L stuff, do not leave #L enabled after loading iterate
attila.lend...@gmail.com**20070426153431]
[Set *list-end-test* to 'endp instead of 'atom, so (iter (for foo :in
something-non-list)) fails instead of silently exists
attila.lend...@gmail.com**20070215151652]
[wrap code in progns, to avoid possiblity of multiple nil tags in tagbody
Henrik Hjelte <hen...@evahjelte.com>**20061025145324]
[test to detect bug, more than one nil tag in tagbody
Henrik Hjelte <hen...@evahjelte.com>**20061025145128]
[Added release.sh
attila.lend...@gmail.com**20060506155953]
[TAG 1.4.3
attila.lend...@gmail.com**20060505134701]
Patch bundle hash:
62134238d49a98e5dbfb86589229ec0896284f3d
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