This PR adds a new option `maxErrors` that limits the number of errors
printed from a single `lean` run, defaulting to 100. Processing is
aborted when the limit is reached, but this is tracked only on a
per-command level.
Smaller values can be useful when making changes that break a lot of
files and would otherwise scroll the actual root failures out of the
terminal view.
This PR adds explanations for a few errors concerning noncomputability,
redundant match alternatives, and invalid inductive declarations.
These adopt a lower-case error naming style, which is also applied to
existing error explanation tests.
This PR adds support for throwing named errors with associated error
explanations. In particular, it adds elaborators for the syntax defined
in #8649, which use the error-explanation infrastructure added in #8651.
This includes completions, hovers, and jump-to-definition for error
names.
Note that another stage0 rebuild will be required to define explanations
using `register_error_explanation`.
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Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>
Co-authored-by: Marc Huisinga <mhuisi@protonmail.com>
