Parsley 4.2.14

Corrected the logic for merging two errors by accounting for both of their offsets: the underlying offset has priority (which is where the error is said to have occurred), and the presentation offset (where the error appears) is checked after: this will not affect anything in the current release, as the two offsets will always match up. Also improved performance stability slightly by using type alias for the identity machinery.

What's Changed

• Refactor/remove-internal-Cont-split by @j-mie6 in #200
• Corrected merge logic by @j-mie6 in #201

Full Changelog: v4.2.13...v4.2.14