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

3 files changed, 28 insertions, 4 deletions

diff --git a/apl9.h b/apl9.h
index 311bceb..2846861 100644
--- a/apl9.h
+++ b/apl9.h
@@ -340,6 +340,9 @@ Array *fnNand(Array *, Array *);
 Array *fnNor(Array *, Array *);
 Array *fnTake(Array *, Array *);
 Array *fnIndex(Array *, Array *);
+Array *fnMembership(Array *, Array *);
+Array *fnUnion(Array *, Array *);
+Array *fnExcluding(Array *, Array *);
 Array *fnCatenateLast(Array *, Array *);
 Array *fnCatenateFirst(Array *, Array *);
 Array *fnReshape(Array *, Array *);
diff --git a/eval.c b/eval.c
index 8829609..5a8d758 100644
--- a/eval.c
+++ b/eval.c
@@ -31,7 +31,7 @@ int bindingstrengths[11][11] = {
 	6, 6, 6, 0, 0, 0, 0, 0, 0, 0, 0, /* DO */
 	3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* AF */
 	0, 0, 0, 0, 0, 0, 0, 8, 9, 0, 0, /* ( */
-	0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, /* ) */
+	8, 8, 8, 8, 8, 8, 8, 8, 9, 8, 8, /* ) */
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* ← */
 	1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* IS */
 	0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, /* N */
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);