[elpa] externals/m-buffer 761ba8e4b7 049/115: Equals and subtract functionality added.

[ELPA Syncer]

branch: externals/m-buffer
commit 761ba8e4b7c770647d23a91871365e7bc6d9305b
Author: Phillip Lord <phillip.lord@newcastle.ac.uk>
Commit: Phillip Lord <phillip.lord@newcastle.ac.uk>

    Equals and subtract functionality added.
---
 m-buffer.el           | 40 ++++++++++++++++++++++++++++++++++++++++
 test/m-buffer-test.el | 30 +++++++++++++++++++++++++++++-
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/m-buffer.el b/m-buffer.el
index 185e35f981..7ca2dafab6 100644
--- a/m-buffer.el
+++ b/m-buffer.el
@@ -297,6 +297,46 @@ function. See `m-buffer-nil-marker' for details."
   (m-buffer-marker-to-pos-nil
    (apply 'm-buffer-match-end match)))
 
+(defun m-buffer-match-equal (m n)
+  "Returns true if m and n are cover the same region.
+Matches are equal if they match the same region; subgroups are
+ignored."
+  ;; can we speed this up by not making subsets?
+  (equal
+   (-take 2 m)
+   (-take 2 n)))
+
+(defun m-buffer-match-subtract (m n)
+  "Remove from M any matches in N.
+Matches are equivalent if overall they match the same
+area; subgroups are ignored.
+See also `m-buffer-match-exact-subtract' which often
+runs faster but has some restrictions."
+  (-remove
+   (lambda (o)
+     (-any?
+      (lambda (p)
+        (m-buffer-match-equal o p))
+      n))
+   m))
+
+(defun m-buffer-match-exact-subtract (m n)
+  "Remove from M any matches in N.
+Both M and N must be fully ordered, and any element in N must be
+in M."
+  ;; copy n
+  (let ((n-eaten n))
+    (-remove
+     (lambda (o)
+       ;; check the first element of n
+       (when (m-buffer-match-equal
+              (car n-eaten) o)
+         ;; we have a match so throw away the first element of n-eaten
+         ;; which we won't need again.
+         (setq n-eaten (-drop 1 n-eaten))
+         t))
+     m)))
+
 ;; marker/position utility functions
 (defun m-buffer-nil-marker (markers)
   "Takes a (nested) list of markers and nils them all.
diff --git a/test/m-buffer-test.el b/test/m-buffer-test.el
index 63ec642c8e..0dd7b5aa86 100644
--- a/test/m-buffer-test.el
+++ b/test/m-buffer-test.el
@@ -157,7 +157,6 @@
      (m-buffer-nil-marker
       (m-buffer-match-begin (current-buffer) "^one$"))))))
 
-
 (ert-deftest replace-matches ()
   (should
    (equal
@@ -307,4 +306,33 @@
        (current-buffer)
        "A"
        :case-fold-search t))))))
+
+
+(ert-deftest subtract ()
+  (should
+   (equal
+    '((1 6) (17 23) (34 39))
+    (m-buffer-wtb-of-file
+     "sentence-end.txt"
+     (m-buffer-marker-tree-to-pos
+      (m-buffer-match-subtract
+       (m-buffer-match-word
+        (current-buffer))
+       (m-buffer-match
+        (current-buffer) "sentence")))))))
+
+(ert-deftest exact-substract ()
+  (should
+   (equal
+    '((1 6) (17 23) (34 39))
+    (m-buffer-wtb-of-file
+     "sentence-end.txt"
+     (m-buffer-marker-tree-to-pos
+      (m-buffer-match-exact-subtract
+       (m-buffer-match-word
+        (current-buffer))
+       (m-buffer-match
+        (current-buffer) "sentence")))))))
+
+
 ;;; m-buffer-test.el ends here