branch: externals/parser-generator
commit 00ffcde76a7d97f07d3c25871203dc2f887f0f7d
Author: Christian Johansson <christ...@cvj.se>
Commit: Christian Johansson <christ...@cvj.se>
Added TODO items
---
parser.el | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/parser.el b/parser.el
index 043e661..c0e7f77 100644
--- a/parser.el
+++ b/parser.el
@@ -701,18 +701,30 @@
(puthash 'e lr-items-e lr-items))
- ;; 2 Suppose that we have constructed V(X1,X2,...,Xi-1)
+ ;; TODO 2 Suppose that we have constructed V(X1,X2,...,Xi-1)
;; we construct V(X1,X2,...,Xi) as follows:
-
- ;; (a) If [A -> a . XiB, u] is in V(X1,...,Xi-1)
- ;; add [A -> aXi . B, u] to V(X1,...,Xi)
-
- ;; (b) If [A -> a . Bb, u] has been placed in V(X1,...,Xi)
- ;; and B -> D is in P
- ;; then add [B -> . D, x] to V(X1,...,Xi) for each x in FIRST(bu)
- ;; provided it is not already there
-
- ;; (c) Repeat step (2b) until no more new items can be added to
V(X1,...,Xi)
+ (let ((prefix-acc)
+ (prefix-new)
+ (prefix-previous (gethash 'e lr-items)))
+ (dolist (prefix γ)
+ (setq prefix-acc (append prefix-acc prefix))
+
+ (dolist (lr-item prefix-previous)
+ ;; TODO (a) If [A -> a . XiB, u] is in V(X1,...,Xi-1)
+ ;; add [A -> aXi . B, u] to V(X1,...,Xi)
+ )
+
+ ;; TODO (c) Repeat step (2b) until no more new items can be added to
V(X1,...,Xi)
+ (let ((added-new t))
+ (while added-new
+ (setq added-new nil)
+ (dolist (lr-item prefix-new)
+ ;; TODO (b) If [A -> a . Bb, u] has been placed in V(X1,...,Xi)
+ ;; and B -> D is in P then add [B -> . D, x] to V(X1,...,Xi)
for each x in FIRST(bu)
+ ;; provided it is not already there
+ )))
+
+ (setq prefix-previous prefix-acc)))
lr-items)))
