[elpa] externals/parser-generator ef60d96 204/434: Added failing test for new function the generates grammar prefixes

[ELPA Syncer]

branch: externals/parser-generator
commit ef60d962e7701c761560d2f543a4bbcbb1b13106
Author: Christian Johansson <christian@cvj.se>
Commit: Christian Johansson <christian@cvj.se>

    Added failing test for new function the generates grammar prefixes
---
 parser-generator.el           | 48 +++++++++++++++++++++++++++++++++++++++++++
 test/parser-generator-test.el | 16 +++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/parser-generator.el b/parser-generator.el
index 2157d04..2b26858 100644
--- a/parser-generator.el
+++ b/parser-generator.el
@@ -160,6 +160,54 @@
       (error "No grammar G defined!")))
   (nth 0 G))
 
+(defun parser-generator--get-grammar-prefixes ()
+  "Return all prefixes of length look-ahead number of terminals and 
non-terminals."
+  (let ((symbols
+         (append
+          (parser-generator--get-grammar-terminals)
+          (parser-generator--get-grammar-non-terminals)))
+        (prefixes)
+        (added-prefixes (make-hash-table :test 'equal))
+        (k parser-generator--look-ahead-number)
+        (indexes)
+        (index)
+        (prefix)
+        (prefix-indexes))
+    (let ((symbols-length (length symbols))
+          (i 0)
+          (found-new t))
+
+      ;; Initialize indexes
+      (while (< i k)
+        (push 0 indexes)
+        (setq i (1+ i)))
+
+      (while found-new
+        ;; Reset variables
+        (setq found-new nil)
+        (setq i 0)
+        (setq prefix nil)
+        (setq prefix-indexes nil)
+
+        ;; Build prefix and prefix-indexes from actual state
+        (while (< i k)
+          (setq index (nth i indexes))
+          (push (nth index symbols) prefix)
+          (push index prefix-indexes)
+          (setq i (1+ i)))
+
+        (message "prefix: %s" prefix)
+
+        ;; If prefix is new add to list
+        (unless (gethash prefix-indexes added-prefixes)
+          (push prefix prefixes)
+          (puthash prefix-indexes t added-prefixes))
+
+        ;; TODO Try to find a new index here
+
+        ))
+    (sort prefixes 'parser-generator--sort-list)))
+
 (defun parser-generator--get-grammar-production-number (production)
   "If PRODUCTION exist, return it's number."
   (unless parser-generator--table-productions-number
diff --git a/test/parser-generator-test.el b/test/parser-generator-test.el
index ec8e1b8..5d74105 100644
--- a/test/parser-generator-test.el
+++ b/test/parser-generator-test.el
@@ -694,6 +694,21 @@
 
   (message "Passed tests  for (parser-generator--merge-max-terminals)"))
 
+(defun parser-generator-test--get-grammar-prefixes ()
+  "Test `parser-generator--get-grammar-prefixes'."
+  (message "Passed tests  for (parser-generator--get-grammar-prefixes)")
+
+  (parser-generator-set-look-ahead-number 1)
+  (parser-generator-set-grammar '((S A B) ("a" "b") ((S A) (S (B)) (B "a") (A 
"a") (A ("b" "a"))) S))
+  (parser-generator-process-grammar)
+
+  (should
+   (equal
+    '(("a") (A) ("b") (B) (S))
+    (parser-generator--get-grammar-prefixes)))
+
+  (message "Passed tests  for (parser-generator--get-grammar-prefixes)"))
+
 (defun parser-generator-test ()
   "Run test."
   ;; (setq debug-on-error t)
@@ -711,6 +726,7 @@
   (parser-generator-test--get-grammar-rhs)
   (parser-generator-test--get-grammar-look-aheads)
   (parser-generator-test--merge-max-terminals)
+  (parser-generator-test--get-grammar-prefixes)
 
   ;; Algorithms
   (parser-generator-test--first)