branch: externals/parser-generator
commit 5da1b2824e9fd903b6b94d23dc50d218b455fac0
Author: Christian Johansson <[email protected]>
Commit: Christian Johansson <[email protected]>
Added TODO item
---
parser.el | 1 +
test/parser-test.el | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/parser.el b/parser.el
index a2a6811..e13a305 100644
--- a/parser.el
+++ b/parser.el
@@ -652,6 +652,7 @@
(setq follow-set (parser--distinct follow-set)))
follow-set))
+;; TODO Don't check for distincts prefixes but LR-items
;; Algorithm 5.9, p. 389
(defun parser--lr-items-for-grammar ()
"Calculate set of valid LR(k) items for grammar."
diff --git a/test/parser-test.el b/test/parser-test.el
index fe8d099..caed787 100644
--- a/test/parser-test.el
+++ b/test/parser-test.el
@@ -304,6 +304,41 @@
(parser--lr-items-for-prefix '(S b))))
(message "Passed V(Sb)")
+ ;; a3 p. 390
+ (should
+ (equal
+ '((S (S) (a S b) (a))
+ (S (S) (a S b) (b))
+ (S (S a S) (b) (a))
+ (S (S a S) (b) (e)))
+ (parser--lr-items-for-prefix '(S a S))))
+ (message "Passed V(SaS)")
+
+ (should
+ (equal
+ nil
+ (parser--lr-items-for-prefix '(S a a))))
+ (message "Passed V(Saa)")
+
+ (should
+ (equal
+ nil
+ (parser--lr-items-for-prefix '(S a b))))
+ (message "Passed V(Sab)")
+
+ ;; a4 p. 390
+ (should
+ (equal
+ '((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 (e)))
+ (parser--lr-items-for-prefix '(S a S b))))
+ (message "Passed V(SaSb)")
+
+
(message "Passed tests for (parser--lr-items-for-prefix)"))
(defun parser-test--valid-grammar-p ()
