Effects

Keep a computation in a function so its inputs and outputs are clear. The reference specifies the wider effect-contract design.

sum = (left:int64 right:int64):>int64 => left+right
printl(sum(20 22))

Expected output:

42

Run the example from a file with dewy example.dewy. Its exact output is checked by the website build on the native release target.

Design boundary. The Effects reference specifies the complete language rules. A passing example covers this program only. See generated coverage for related acceptance programs and unmeasured areas.

The example above does not measure general refinement proofs, effect inference, or a no-allocation guarantee. Those remain separate design contracts.