Implement membership (X∊Y), excluding (X~Y) and union (X∪Y)

1 files changed, 24 insertions, 3 deletions

diff --git a/functions.c b/functions.c
index eedacb9..ad87c11 100644
--- a/functions.c
+++ b/functions.c
@@ -102,11 +102,11 @@ fndyad dyadfunctiondefs[] = {
 	0, /* ⍒ */
 	0, /* ⍳ */
 	0, /* ⍸ */
-	0, /* ∊ */
+	fnMembership, /* ∊ */
 	0, /* ⍷ */
-	0, /* ∪ */
+	fnUnion, /* ∪ */
 	0, /* ∩ */
-	0, /* ~ */
+	fnExcluding, /* ~ */
 	fnCatenateLast, /* , */
 	fnCatenateFirst, /* ⍪ */
 	fnReshape, /* ⍴ */
@@ -1137,6 +1137,27 @@ fnIndex(Array *left, Array *right)
 }
 
 Array *
+fnMembership(Array *left, Array *right)
+{
+	/* TODO avoid outer product */
+	return rundfn(L"∨/⍺≡⌾⍵", nil, nil, left, right);
+}
+
+Array *
+fnUnion(Array *left, Array *right)
+{
+	if(left->rank > 1 || right->rank > 1)
+		throwerror(nil, ERank);
+	return rundfn(L"⍺⍪⍵~⍺", nil, nil, left, right);
+}
+
+Array *
+fnExcluding(Array *left, Array *right)
+{
+	return rundfn(L"(~⍺∊⍵)⌿⍺", nil, nil, left, right);
+}
+
+Array *
 fnCatenateLast(Array *left, Array *right)
 {
 	return rundfn(L"⍉(⍉⍺)⍪⍉⍵", nil, nil, left, right);