Merlin 4.9

We are pleased to announce the release of Merlin 4.9 for OCaml 4.14.1 and 5.0.

This maintenance release brings multiple bug fixes and improvements. In particular we identified and patched an important memory consumption issue that could greatly affect Merlin’s performance in heavily functorized projects.

See full changelog
  • merlin binary
    • Allow monadic IO in dot protocol (#1581)
    • Add a scope option to the occurrences command in preparation for the upcoming project-wide-occurrences feature (#1596)
    • Construct bool-typed holes as false instead of true in the construct command, for consistency (#1599).
    • Add a hook to configure system command for spawning ppxes when Merlin is used as a library. (#1585)
    • Implement an all-or-nothing cache for the PPX phase (#1584)
    • Cleanup functors caches when backtracking, to avoid memory leaks (#1609, fixes #1529 and ocaml-lsp#1032)
    • Fix construct results ordering for sum types sand poly variants (#1603)
    • Fix object method completion not working (#1606, fixes #1575)
    • Improve context detection for package types (#1608, fixes #1607)
    • Fix incorrect locations for string literals (#1574)
    • Fixed an issue that caused errors to erroneously alert about missing cmi files (#1577)
    • Prevent destruct from crashing on closed variant types (#1602, fixes #1601)
    • Improve longident parsing (#1612, fixes #945)
  • editor modes
    • emacs: call the user's configured completion UI in merlin-construct (#1598)
  • test suite
    • Add missing dependency to a test using ppxlib (#1583)
    • Add tests for the new PPX phase cache (#1584)
    • Add and update tests for construct ordering (#1603)