2DUP
Duplicates the pair of two topmost items
Input stack: a b
Output stack: a b a b
In this example, a pair of two items (0x10 and 0x20) is
duplicated.
PumpkinDB> 0x10 0x20 2DUP
0x10 0x20 0x10 0x20
Allocation
None
Errors
EmptyStack error if there are less than two items available on the stack
Tests
2dup_copies_a_pair : 0x10 0x20 2DUP 4 WRAP 0x10 0x20 OVER OVER 4 WRAP EQUAL?.
2dup_requires_two_items_0 : [2DUP] TRY UNWRAP 0x04 EQUAL?.
2dup_requires_two_items_1 : [1 2DUP] TRY UNWRAP 0x04 EQUAL?.