branch: externals/parser-generator
commit e3d30078032be844aa572f81210c5e114246bebe
Author: Christian Johansson <christ...@cvj.se>
Commit: Christian Johansson <christ...@cvj.se>
Tweaking of action-table generation for canonical LR-parser
---
parser-lr.el | 13 +++++++++----
parser.el | 2 +-
test/parser-lr-test.el | 24 ++++++++++++++++++++++++
3 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/parser-lr.el b/parser-lr.el
index ed1f8dd..c234817 100644
--- a/parser-lr.el
+++ b/parser-lr.el
@@ -76,7 +76,8 @@
;; (message "Cv: %s" Cv)
(when Cv
(let ((eff (parser--e-free-first Cv)))
- ;; (message "eff: %s" eff)
+ ;; TODO This does not return correct
+ (message "EFF%s: %s" Cv eff)
(when eff
;; Go through eff-items and see if any item
is a valid look-ahead of grammar
;; in that case save in action table a shift
action here
@@ -106,14 +107,18 @@
;; (b) f(u) = reduce i if [A -> B ., u] is in a and A ->
B is production i in P, i > 1
(when (and
(nth 0 lr-item)
- (nth 1 lr-item)
(not (nth 2 lr-item)))
- (let ((u (nth 3 lr-item)))
+ (let ((A (nth 0 lr-item))
+ (B (nth 1 lr-item))
+ (u (nth 3 lr-item)))
+ (unless B
+ (setq B (list parser--e-identifier)))
(when (parser--valid-look-ahead-p u)
(let ((hash-key (format "%s-%s-%s" goto-index
state u)))
(unless (gethash hash-key added-actions)
(puthash hash-key t added-actions)
- (let ((production (list (nth 0 lr-item)
(append (nth 1 lr-item) (nth 2 lr-item)))))
+ (let ((production (list A B)))
+ ;; (message "production: %s" production)
(let ((production-number
(parser--get-grammar-production-number production)))
(unless production-number
(error "Expecting production number for
%s from LR-item %s!" production lr-item))
diff --git a/parser.el b/parser.el
index d4a110b..f025db9 100644
--- a/parser.el
+++ b/parser.el
@@ -237,7 +237,7 @@
(puthash lhs (nreverse new-value) parser--table-productions-rhs))))
(setq parser--table-productions-number (make-hash-table :test 'equal))
- (let ((production-index 1))
+ (let ((production-index 0))
(dolist (p productions)
(let ((lhs (car p))
(rhs (cdr p))
diff --git a/test/parser-lr-test.el b/test/parser-lr-test.el
index 5ab16e0..1c7105f 100644
--- a/test/parser-lr-test.el
+++ b/test/parser-lr-test.el
@@ -22,6 +22,30 @@
(parser-lr--generate-goto-tables)
(parser-lr--generate-action-tables)
+ (should
+ (equal
+ '((0 ((S 1)))
+ (1 ((a 2)))
+ (2 ((S 3)))
+ (3 ((a 4) (b 5)))
+ (4 ((S 6)))
+ (5 nil)
+ (6 ((a 4) (b 7)))
+ (7 nil))
+ parser-lr--goto-tables))
+
+ (should
+ (equal
+ '((0 ((S nil (S a S b) (a)) (S nil (S a S b) (e)) (S nil nil (a)) (S nil
nil (e)) (Sp nil (S) (e))))
+ (1 ((S (S) (a S b) (a)) (S (S) (a S b) (e)) (Sp (S) nil (e))))
+ (2 ((S (S a) (S b) (a)) (S (S a) (S b) (e)) (S nil (S a S b) (a)) (S nil
(S a S b) (b)) (S nil nil (a)) (S nil nil (b))))
+ (3 ((S (S) (a S b) (a)) (S (S) (a S b) (b)) (S (S a S) (b) (a)) (S (S a
S) (b) (e))))
+ (4 ((S (S a) (S b) (a)) (S (S a) (S b) (b)) (S nil (S a S b) (a)) (S nil
(S a S b) (b)) (S nil nil (a)) (S nil nil (b))))
+ (5 ((S (S a S b) nil (a)) (S (S a S b) nil (e))))
+ (6 ((S (S) (a S b) (a)) (S (S) (a S b) (b)) (S (S a S) (b) (a)) (S (S a
S) (b) (b))))
+ (7 ((S (S a S b) nil (a)) (S (S a S b) nil (b)))))
+ (parser--hash-to-list parser-lr--items)))
+
;; Fig. 5.9 p. 374
(should
(equal
