Add a next multiple element (∆*)

Closes #1377

documents/knowledge/elements.yaml

@@ -1352,7 +1352,7 @@
       - "[[3,1,2]] : [1,2,3]"
       - "[312] : 123"
       - '["bca"] : "abc"'
-      - '[0] : 0'
+      - "[0] : 0"
 
 - element: "t"
   name: Tail
@@ -4391,6 +4391,19 @@
       - "[6] : [1, 1]"
       - "[4] : [2]"
 
+- element: "∆*"
+  name: Next Multiple
+  arity: 2
+  description: Get the next multiple of a number greater than another number
+  overloads:
+      num, num: get the next multiple of b that is greater than a
+  vectorise: true
+  tests:
+      - "[6, 5] : 10"
+      - "[4, 5] : 5"
+      - "[5, 5] : 10"
+      - "[0, -1] : -1"
+
 - element: "øb"
   name: Parenthesise
   arity: 1
@@ -4553,7 +4566,7 @@
   tests:
       - '["ababa", "aba"] : 2'
       - '["bbba", "ba"] : 1'
-      - '[[1, 2, 2, 1, 2, 1], [1, 2]] : 2'
+      - "[[1, 2, 2, 1, 2, 1], [1, 2]] : 2"
       - '[[3, "3", 3, "3", 3], [3, "3", 3]] : 2'
 
 - element: "øV"

vyxal/elements.py

@@ -3361,6 +3361,17 @@ def newline_split(lhs, ctx):
     }.get(vy_type(lhs), lambda: vectorise(newline_split, lhs, ctx=ctx))()
 
 
+def next_multiple(lhs, rhs, ctx):
+    """Element ∆*
+    (num, num) -> get the next multiple of b that is greater than a
+    """
+
+    ts = vy_type(lhs, rhs)
+    return {
+        (NUMBER_TYPE, NUMBER_TYPE): lambda: lhs + rhs - lhs % rhs,
+    }.get(ts, lambda: vectorise(next_multiple, lhs, rhs, ctx=ctx))()
+
+
 def next_prime(lhs, ctx):
     """Element ∆Ṗ
     (num) -> next prime after a
@@ -6631,6 +6642,7 @@ def zfiller(lhs, rhs, ctx):
     "∆›": process_element(increment_until_false, 2),
     "∆‹": process_element(decrement_until_false, 2),
     "∆ǐ": process_element(prime_exponents, 1),
+    "∆*": process_element(next_multiple, 2),
     "øḂ": process_element(angle_bracketify, 1),
     "øḃ": process_element(curly_bracketify, 1),
     "øb": process_element(parenthesise, 1),