This PR addresses a missing check in the module system where private
names that remain in the public environment map for technical reasons
(e.g. inductive constructors generated by the kernel and relied on by
the code generator) accidentally were accessible in the public scope.
This PR strips `lib` prefixes and `_shared` suffixes from plugin names.
It also moves most of the dynlib processing code to Lean to make such
preprocessing more standard.
This PR adds `Lean.loadPlugin` which exposes functionality similar to
the `lean` executable's `--plugin` option to Lean code.
This will allow custom Lean frontends (e.g., Lake, the Lean language
server) to also load plugins.
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Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
