epher

epher is a calculator language: you write ordinary math, with units
that convert, and every statement's answer appears inline right next
to the line that produced it.
The rock ships the runtime files and the Lua module that wire the
shared epher language server into Neovim: live diagnostics, inline
answers as inlay hints, hover signatures, completion, definition
jumps, and the EpherRun results window.
The epher-lsp binary is a separate download from the GitHub
releases page; after that everything runs locally.