Mappi finds (Python – portability not guaranteed) expressions that map a given range of input values (likely integers) to a linear output range.
The output of the expressions generated are unspecified for any other input value.
Requires Python 3.7+.
Spend up to 5 seconds finding a function that maps [10, 32, 35] to 0..2:
$ python3 -m mappi --default-functions --input 10,32,35 --time-limit=5
=== BEST RESULT ===
Original: (x << a) & b
Expression: (x & 9) % 3
Mapping: {10: 2, 32: 0, 35: 1}Spend up to 5 seconds finding a function that maps [1,3,5,7,19] to 0..4 in the same order:
$ python3 -m mappi --default-functions --input 1,3,5,7,19 --time-limit=5 --strict-order
=== BEST RESULT ===
Original: x*a+b
Expression: (x*3+2) % 5
Mapping: {1: 0, 3: 1, 5: 2, 7: 3, 19: 4}Use a custom function:
$ python3 -m mappi --function 'x<<(a>>b)&c' --input 10,32,35,72,691
=== BEST RESULT ===
Original: x<<(a>>b)&c
Expression: (x<<(8>>6)&205) % 5
Mapping: {10: 3, 32: 0, 35: 1, 72: 2, 691: 4}
