VIP: start and length args in slice should be uint256

[iamdefinitelyahuman]

Simple Summary

The start and length args in the builtin function slice should be expected as uint256.

Motivation

We do not use negative values for indexing, so a negative start index or length already won't work. There is no need for int128 here.

Specification

Change the function signature to:

slice(b: bytes, start: uint256, length: uint256) → bytes

Backwards Compatibility

This is a breaking change.

Copyright

Copyright and related rights waived via CC0