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Diffstat (limited to 'third_party/lisp/quasiquote_2/quasiquote-2.0.lisp')
| -rw-r--r-- | third_party/lisp/quasiquote_2/quasiquote-2.0.lisp | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/third_party/lisp/quasiquote_2/quasiquote-2.0.lisp b/third_party/lisp/quasiquote_2/quasiquote-2.0.lisp new file mode 100644 index 0000000000..10043fe0ec --- /dev/null +++ b/third_party/lisp/quasiquote_2/quasiquote-2.0.lisp @@ -0,0 +1,340 @@ +;;;; quasiquote-2.0.lisp + +(in-package #:quasiquote-2.0) + +(defparameter *env* nil) + +(defmacro nonsense-error (str) + `(error ,(concatenate 'string + str + " appears as a bare, non DIG-enclosed form. " + "For now I don't know how to make sense of this."))) + +(defmacro define-nonsense-when-bare (name) + `(defmacro ,name (n-or-form &optional form) + (declare (ignore n-or-form form)) + (nonsense-error ,(string name)))) + +(define-nonsense-when-bare inject) +(define-nonsense-when-bare oinject) +(define-nonsense-when-bare splice) +(define-nonsense-when-bare osplice) +(define-nonsense-when-bare macro-inject) + +(defparameter *depth* 0) + + +(defparameter *injectors* nil) + +(defparameter *void-elt* nil) +(defparameter *void-filter-needed* nil) + +;; (defmacro with-injector-parsed (form) +;; `(let ((kwd (intern (string + +(defun reset-injectors () + (setf *injectors* nil)) + +(defparameter *known-injectors* '(inject splice oinject osplice + macro-inject omacro-inject + macro-splice omacro-splice + macro-inject-all omacro-inject-all + macro-splice-all omacro-splice-all)) + +(defun injector-form-p (form) + (and (consp form) + (find (car form) *known-injectors* :test #'eq))) + +(defun injector-level (form) + (if (equal 2 (length form)) + 1 + (cadr form))) + +(defun injector-subform (form) + (if (equal 2 (length form)) + (values (cdr form) '(cdr)) + (values (cddr form) '(cddr)))) + +(defparameter *opaque-injectors* '(odig oinject osplice omacro-inject)) + +(defun transparent-p (form) + (not (find (car form) *opaque-injectors* :test #'eq))) + +(defun look-into-injector (form path) + (let ((*depth* (- *depth* (injector-level form)))) + (multiple-value-bind (subform subpath) (injector-subform form) + (search-all-active-sites subform (append subpath path) nil)))) + +(defparameter *known-diggers* '(dig odig)) + +(defun dig-form-p (form) + (and (consp form) + (find (car form) *known-diggers* :test #'eq))) + +(defun look-into-dig (form path) + (let ((*depth* (+ *depth* (injector-level form)))) + (multiple-value-bind (subform subpath) (injector-subform form) + (search-all-active-sites subform (append subpath path) nil)))) + +(defun handle-macro-1 (form) + (if (atom form) + (error "Sorry, symbol-macros are not implemented for now") + (let ((fun (macro-function (car form) *env*))) + (if (not fun) + (error "The subform of MACRO-1 injector is supposed to be macro, perhaps, something went wrong...")) + (macroexpand-1 form *env*)))) + +(defun handle-macro-all (form) + (if (atom form) + (error "Sorry, symbol-macros are not implemented for now") + (macroexpand form *env*))) + + +(defparameter *macro-handlers* `((macro-inject . ,#'handle-macro-1) + (omacro-inject . ,#'handle-macro-1) + (macro-splice . ,#'handle-macro-1) + (omacro-splice . ,#'handle-macro-1) + (macro-inject-all . ,#'handle-macro-all) + (omacro-inject-all . ,#'handle-macro-all) + (macro-splice-all . ,#'handle-macro-all) + (omacro-splice-all . ,#'handle-macro-all))) + +(defun get-macro-handler (sym) + (or (cdr (assoc sym *macro-handlers*)) + (error "Don't know how to handle this macro injector: ~a" sym))) + + + +(defun macroexpand-macroinjector (place) + (if (not (splicing-injector (car place))) + (progn (setf (car place) (funcall (get-macro-handler (caar place)) + (car (injector-subform (car place))))) + nil) + (let ((new-forms (funcall (get-macro-handler (caar place)) + (car (injector-subform (car place)))))) + (cond ((not new-forms) + (setf *void-filter-needed* t + (car place) *void-elt*)) + ((atom new-forms) (error "We need to splice the macroexpansion, but got atom: ~a" new-forms)) + (t (setf (car place) (car new-forms)) + (let ((tail (cdr place))) + (setf (cdr place) (cdr new-forms) + (cdr (last new-forms)) tail)))) + t))) + + +(defun search-all-active-sites (form path toplevel-p) + ;; (format t "SEARCH-ALL-ACTIVE-SITES: got form ~a~%" form) + (if (not form) + nil + (if toplevel-p + (cond ((atom (car form)) :just-quote-it!) + ((injector-form-p (car form)) (if (equal *depth* (injector-level (car form))) + :just-form-it! + (if (transparent-p (car form)) + (look-into-injector (car form) (cons 'car path))))) + ((dig-form-p (car form)) + ;; (format t "Got dig form ~a~%" form) + (if (transparent-p (car form)) + (look-into-dig (car form) (cons 'car path)))) + (t (search-all-active-sites (car form) (cons 'car path) nil) + (search-all-active-sites (cdr form) (cons 'cdr path) nil))) + (when (consp form) + (cond ((dig-form-p (car form)) + ;; (format t "Got dig form ~a~%" form) + (if (transparent-p (car form)) + (look-into-dig (car form) (cons 'car path)))) + ((injector-form-p (car form)) + ;; (format t "Got injector form ~a ~a ~a~%" form *depth* (injector-level (car form))) + (if (equal *depth* (injector-level (car form))) + (if (macro-injector-p (car form)) + (progn (macroexpand-macroinjector form) + (return-from search-all-active-sites + (search-all-active-sites form path nil))) + (progn (push (cons form (cons 'car path)) *injectors*) + nil)) + (if (transparent-p (car form)) + (look-into-injector (car form) (cons 'car path))))) + (t (search-all-active-sites (car form) (cons 'car path) nil))) + (search-all-active-sites (cdr form) (cons 'cdr path) nil))))) + + + +(defun codewalk-dig-form (form) + (reset-injectors) + (let ((it (search-all-active-sites form nil t))) + (values (nreverse *injectors*) it))) + +(defun %codewalk-dig-form (form) + (if (not (dig-form-p form)) + (error "Supposed to be called on dig form") + (let ((*depth* (+ (injector-level form) *depth*))) + (codewalk-dig-form (injector-subform form))))) + +(defun path->setfable (path var) + (let ((res var)) + ;; First element is artifact of extra CAR-ing + (dolist (spec (cdr (reverse path))) + (setf res (list spec res))) + res)) + +(defun tree->cons-code (tree) + (if (atom tree) + `(quote ,tree) + `(cons ,(tree->cons-code (car tree)) + ,(tree->cons-code (cdr tree))))) + +(defparameter *known-splicers* '(splice osplice + macro-splice omacro-splice + macro-splice-all omacro-splice-all)) + +(defun splicing-injector (form) + (and (consp form) + (find (car form) *known-splicers* :test #'eq))) + +(defparameter *known-macro-injectors* '(macro-inject omacro-inject + macro-splice omacro-splice + macro-inject-all omacro-inject-all + macro-splice-all omacro-splice-all + )) + +(defun macro-injector-p (form) + (and (consp form) + (find (car form) *known-macro-injectors* :test #'eq))) + +(defun filter-out-voids (lst void-sym) + (let (caars cadrs cdars cddrs) + ;; search for all occurences of VOID + (labels ((rec (x) + (if (consp x) + (progn (cond ((consp (car x)) + (cond ((eq void-sym (caar x)) (push x caars)) + ((eq void-sym (cdar x)) (push x cdars)))) + ((consp (cdr x)) + (cond ((eq void-sym (cadr x)) (push x cadrs)) + ((eq void-sym (cddr x)) (push x cddrs))))) + (rec (car x)) + (rec (cdr x)))))) + (rec lst)) + (if (or cdars cddrs) + (error "Void sym found on CDR position, which should not have happened")) + ;; destructively transform LST + (dolist (elt caars) + (setf (car elt) (cdar elt))) + (dolist (elt cadrs) + (setf (cdr elt) (cddr elt))) + ;; check that we indeed filtered-out all VOIDs + (labels ((rec (x) + (if (not (atom x)) + (progn (rec (car x)) + (rec (cdr x))) + (if (eq void-sym x) + (error "Not all VOIDs were filtered"))))) + (rec lst)) + lst)) + +(defun transform-dig-form (form) + (let ((the-form (copy-tree form))) + (let ((*void-filter-needed* nil) + (*void-elt* (gensym "VOID"))) + (multiple-value-bind (site-paths cmd) (%codewalk-dig-form the-form) + (cond ((eq cmd :just-quote-it!) + `(quote ,(car (injector-subform the-form)))) + ((eq cmd :just-form-it!) + (car (injector-subform (car (injector-subform the-form))))) + (t (let ((cons-code (if (not site-paths) + (tree->cons-code (car (injector-subform the-form))) + (really-transform-dig-form the-form site-paths)))) + (if (not *void-filter-needed*) + cons-code + `(filter-out-voids ,cons-code ',*void-elt*))))))))) + +(defmacro make-list-form (o!-n form) + (let ((g!-n (gensym "N")) + (g!-i (gensym "I")) + (g!-res (gensym "RES"))) + `(let ((,g!-n ,o!-n) + (,g!-res nil)) + (dotimes (,g!-i ,g!-n) + (push ,form ,g!-res)) + (nreverse ,g!-res)))) + +(defun mk-splicing-injector-let (x) + `(let ((it ,(car (injector-subform x)))) + (assert (listp it)) + (copy-list it))) + + + +(defun mk-splicing-injector-setf (path g!-list g!-splicee) + (assert (eq 'car (car path))) + (let ((g!-rest (gensym "REST"))) + `(let ((,g!-rest ,(path->setfable (cons 'cdr (cdr path)) g!-list))) + (assert (or (not ,g!-rest) (consp ,g!-rest))) + (if (not ,g!-splicee) + (setf ,(path->setfable (cdr path) g!-list) + ,g!-rest) + (progn (setf ,(path->setfable (cdr path) g!-list) ,g!-splicee) + (setf (cdr (last ,g!-splicee)) ,g!-rest)))))) + + +(defun really-transform-dig-form (the-form site-paths) + (let ((gensyms (make-list-form (length site-paths) (gensym "INJECTEE")))) + (let ((g!-list (gensym "LIST"))) + (let ((lets nil) + (splicing-setfs nil) + (setfs nil)) + (do ((site-path site-paths (cdr site-path)) + (gensym gensyms (cdr gensym))) + ((not site-path)) + (destructuring-bind (site . path) (car site-path) + (push `(,(car gensym) ,(if (not (splicing-injector (car site))) + (car (injector-subform (car site))) + (mk-splicing-injector-let (car site)))) + lets) + (if (not (splicing-injector (car site))) + (push `(setf ,(path->setfable path g!-list) ,(car gensym)) setfs) + (push (mk-splicing-injector-setf path g!-list (car gensym)) splicing-setfs)) + (setf (car site) nil))) + `(let ,(nreverse lets) + (let ((,g!-list ,(tree->cons-code (car (injector-subform the-form))))) + ,@(nreverse setfs) + ;; we apply splicing setf in reverse order for them not to bork the paths of each other + ,@splicing-setfs + ,g!-list)))))) + + +;; There are few types of recursive injection that may happen: +;; * compile-time injection: +;; (dig (inject (dig (inject a)))) -- this type will be handled automatically by subsequent macroexpansions +;; * run-time injection: +;; (dig (dig (inject 2 a))) +;; and A is '(dig (inject 3 'foo)) -- this one we guard against ? (probably, first we just ignore it +;; -- do not warn about it, and then it wont really happen. +;; * macroexpanded compile-time injection: +;; (dig (inject (my-macro a b c))), +;; where MY-MACRO expands into, say (splice (list 'a 'b 'c)) +;; This is *not* handled automatically, and therefore we must do it by hand. + + +;; OK, now how to implement splicing ? +;; (dig (a (splice (list b c)) d)) +;; should transform into code that yields +;; (a b c d) +;; what this code is? +;; (let ((#:a (copy-list (list b c)))) +;; (let ((#:res (cons 'a nil 'd))) +;; ;; all non-splicing injects go here, as they do not spoil the path-structure +;; (setf (cdr #:res) #:a) +;; (setf (cdr (last #:a)) (cdr (cdr #:res))) +;; #:res))) + + +;; How this macroexpansion should work in general? +;; * We go over the cons-tree, keeping track of the depth level, which is +;; controlled by DIG's +;; * Once we find the INJECT with matching level, we remember the place, where +;; this happens +;; * We have two special cases: +;; * cons-tree is an atom +;; * cons-tree is just a single INJECT |