After this commit, new interactice tactic classes can be added without
writing C++ code (see example: tests/lean/run/my_tac_class.lean).
The tactic_evaluator was simplified, and all the complexity has been
moved to tactic_notation, and lean code.
We can now inspect the intermediate states produced by the rewrite
tactic.
The function (@scope_trace _ line col thunk) can be used to position trace
messages produced by thunk. If line/col are not provided (i.e., we
just write (scope_trace thunk)), then line/col are filled with the
position of this term by the elaborator.
We can visualize the intermediate tactic states inside nested blocks
such as (try { ... })
The new infrastructure can be used to implement custom tactic_state
pretty printers.
@kha, I added autocompletion for ^. I try to elaborate the expression
before ^. using the local context provided by the parser.
The autocompletion only works if the type for the expression before ^. can be
inferred. This is a big limitation because this information cannot be
obtained in many cases. Here are examples that do not work:
meta def proof_for (e : expr) : smt_tactic expr :=
do cc ← to_cc_state, cc^.proof_for e
--^ does not work here
If we annotate cc with its type, it works:
meta def proof_for (e : expr) : smt_tactic expr :=
do cc : cc_state ← to_cc_state, cc^.proof_for e
--^ works
We don't have typing information on the equation lhs at
autocompletion time. So, the following will not work
private meta def mk_smt_goals_for (cfg : smt_config)
: list expr → list smt_goal → list expr → tactic (list smt_goal × list expr)
| [] sr tr := return (sr^.reverse, tr^.reverse)
--^ does not work since
| (tg::tgs) sr tr := ...
