IF
Provides conditional flow control depending on a boolean value.
Input stack: a [b]
Output stack: maybe b
IF will push the result [b] to the stack if a is 1.
PumpkinDB> 0x01 [0x20] IF
0x20
PumpkinDB> 0x00 [0x20] IF
Allocation
None
Errors
EmptyStack error if there are less than two items on the stack
InvalidValue error if the value being checked for truth is not a boolean.
Decoding error error if the code is undecodable.
Tests
works : 1 [2] IF 2 EQUAL?.
invalid_code : [1 1 IF] TRY UNWRAP 0x05 EQUAL?.
invalid_value : [5 [1] IF] TRY UNWRAP 0x03 EQUAL?.
requires_two_items_0 : [IF] TRY UNWRAP 0x04 EQUAL?.
requires_two_items_1 : [[] IF] TRY UNWRAP 0x04 EQUAL?.