Catamorphism: Difference between revisions

=={{header|BQN}}==

BQN has two different primitives for catamorphism:

- Fold(<code>´</code>): Works on lists only.

- Insert(<code>˝</code>): Works on arrays with higher rank.

Both of these primitives take a dyadic function, and an optional initial element.

<pre>•Show +´ 30‿1‿20‿2‿10

•Show +˝ 30‿1‿20‿2‿10

•Show tab ← (2+↕5) |⌜ 9+↕3

•Show +˝ tab</pre>

<pre>63

┌·

· 63

┘

┌─

╵ 1 0 1

0 1 2

1 2 3

4 0 1

3 4 5

┘

⟨ 9 7 12 ⟩</pre>