- Lean strings (like std::string) may contain null characters. The
codebase was ignoring this issue.
- We now have a wrapper `string_ref` for wrapping Lean string objects in
C++. This wrapper also implements correctly the coercions std::string <-> string_ref.
Remark: I also found a few places where the code relies on the
following property which is not true
Forall s : std::string, std::string(s.c_str()) == s
- `name` object wrapper was assuming that all numerals were small
`nat` values. This is true in most cases, but the system would
crash when processing if it is a big number.
- The commit tries to make sure runtime/util/kernel are correct.
Modules that will be deleted contain many `TODO` comments
indicating they may crash and/or produce incorrect results
when strings contain null characters and numerals are big.
cc @kha
@kha: I thought about using `string` instead of `string_ref`.
We consistently use `std::string`. So, it should be fine, but I
was concerned about code readability.
After we bootstrap Lean4, we will be able to delete `lean::list`
template, and rename `lean::list_ref` to `lean::list`.
I am going to add `pair_ref` for wrapping Lean pair objects.
If we use `lean::string` instead of `lean::string_ref`, then
we should also use `lean::pair` instead of `lean::pair_ref`.
But, there is a problem in this case since we have
https://github.com/leanprover/lean4/blob/master/src/util/pair.h#L13
:(
@kha The runtime folder includes what is needed to link a
standalone Lean program. It is still contains some unnecessary files.
We will be able to remove them after we release Lean4.
@kha: I decided to implement this change before I start the
type_context modifications. The change did not affect the corelib and
test suite much. The only annoying problem is that `out` cannot be
used to name locals anymore.
Motivation: see "Other goodies" section at
https://github.com/leanprover/lean/wiki/Refactoring-structures
We had to add a new transparency mode: Instances at type_context.
In this mode, instances and reducible definitions are considered
transparent.
The new mode is used in the defeq_canonizer, code generator,
and sizeof lemma generation at inductive_compiler.
We also use the new mode in the unfold tactics.
quasireducible are also known as lazyreducible.
There is a lot of work to be done.
We still need to revise blast, and add a normalizer for type class
instances. This commit worksaround that by eagerly unfolding
quasireducible.
@avigad and @fpvandoorn, I changed the metaclasses names. They
were not uniform:
- The plural was used in some cases (e.g., [coercions]).
- In other cases a cryptic name was used (e.g., [brs]).
Now, I tried to use the attribute name as the metaclass name whenever
possible. For example, we write
definition foo [coercion] ...
definition bla [forward] ...
and
open [coercion] nat
open [forward] nat
It is easier to remember and is uniform.
