IFELSE
Provides conditional flow control executing different branches of code depending on a boolean value.
Input stack: a [b] [c]
Output stack: maybe b, maybe c
IFELSE will push the result of [c] to the stack if a is 0, or it
will push [b] otherwise.
PumpkinDB> 0x01 [0x20] [0x30] IFELSE
0x20
PumpkinDB> 0x00 [0x20] [0x30] IFELSE
0x30
Allocation
None
Errors
EmptyStack error if there are less than three 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] [3] IFELSE 2 EQUAL?.
works_else : 0 [2] [3] IFELSE 3 EQUAL?.
invalid_code : [1 1 [] IFELSE] TRY UNWRAP 0x05 EQUAL?.
invalid_code_1 : [0 [] 1 IFELSE] TRY UNWRAP 0x05 EQUAL?.
invalid_value : [5 [1] [2] IFELSE] TRY UNWRAP 0x03 EQUAL?.
requires_three_items_0 : [IFELSE] TRY UNWRAP 0x04 EQUAL?.
requires_three_items_1 : [[] IFELSE] TRY UNWRAP 0x04 EQUAL?.
requires_three_items_1 : [[] [] IFELSE] TRY UNWRAP 0x04 EQUAL?.