Implement dyadic (integer only) version of + - × ÷ * ⍟

1 files changed, 38 insertions, 0 deletions

diff --git a/array.c b/array.c
index 4913112..a2afc44 100644
--- a/array.c
+++ b/array.c
@@ -41,3 +41,41 @@ simplescalar(Array *a)
 {
 	return simplearray(a) && a->rank == 0;
 }
+
+Array *
+extend(Array *a, Array *b)
+{
+	/* extend the singleton a to the shape of b */
+	Array *shape = fnShape(b);
+	Array *res = fnReshape(shape, a);
+	freearray(shape);
+	return res;
+}
+
+int
+scalarextend(Array *a, Array *b, Array **aa, Array **bb)
+{
+	/* Extend the arrays a and b to have the same shape.
+	   The resulting arrays are stored in aa and bb,
+	   except when the ranks don't match or extension can't
+	   happen, in which case the function returns 0 and
+	   aa and bb are unchanged.
+	*/
+
+	if(a->size == 1 && b->size != 1){
+		*aa = extend(a, b);
+		*bb = fnSame(b);
+	}else if(b->size == 1 && a->size != 1){
+		*aa = fnSame(a);
+		*bb = extend(b, a);
+	}else if(a->size == b->size && a->rank == b->rank){
+		/* Check that each dimension matches */
+		for(int i = 0; i < a->rank; i++)
+			if(a->shape[i] != b->shape[i])
+				return 0;
+		*aa = fnSame(a);
+		*bb = fnSame(b);
+	}else
+		return 0;
+	return 1;
+}
\ No newline at end of file