This commits also adds a new unit test that demonstrates non-termination due to this kind of constraint.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
The "quota" hack used before this commit was inefficient, and too hackish.
This commit uses two lists of constraints: active and delayed.
The delayed constraints are only processed when there are no active constraints.
We use a simple index to quickly find which delayed constraints have assigned metavariables.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
checkpoint
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
The idea is to catch the inconsistency in constraints such as:
ctx |- ?m[inst:0 v] == fun x, ?m a x
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
The modifications started at commit 1852c86948 made a big difference. For example, before these changes test tests/lean/implicit7.lean generated complicated constraints such as:
[x : Type; a : ?M::29[inst:1 ?M::0[lift:0:1]] x] ⊢ Pi B : Type, (Pi _ : x, (Pi _ : (?M::35[inst:0 #0, inst:1 #2, inst:2 #4, inst:3 #6, inst:5 #5, inst:6 #7, inst:7 #9, inst:9 #9, inst:10 #11, inst:13 ?M::0[lift:0:13]] x a B _), (?M::36[inst:1 #1, inst:2 #3, inst:3 #5, inst:4 #7, inst:6 #6, inst:7 #8, inst:8 #10, inst:10 #10, inst:11 #12, inst:14 ?M::0[lift:0:14]] x a B _ _))) ≈
?M::22 x a
After the changes, only very simple constraints are generated. The most complicated one is:
[] ⊢ Pi a : ?M::0, (Pi B : Type, (Pi _ : ?M::0, (Pi _ : B, ?M::0))) ≈ Pi x : ?M::17, ?M::18
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit also simplifies the method check_pi in the type_checker and type_inferer.
It also fixes process_meta_app in the elaborator.
The problem was in the method process_meta_app and process_meta_inst.
They were processing convertability constrains as equality constraints.
For example, process_meta_app would handle
ctx |- Type << ?f b
as
ctx |- Type =:= ?f b
This is not correct because a ?f that returns (Type U) for b satisfies the first but not the second.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This modification was motivated by a bug exposed by tst17 at tests/kernel/type_checker.
metavar_env is now a smart point to metavar_env_cell.
ro_metavar_env is a read-only smart pointer. It is useful to make sure we are using proof_state correctly.
example showing that the approach for caching metavar_env is broken in the type_checker
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
http://luajit.org/install.html
If you're building a 64 bit application on OSX which links directly or
indirectly against LuaJIT, you need to link your main executable with
these flags:
-pagezero_size 10000 -image_base 100000000
The environment object is a "smart-pointer".
Before this commit, the use of "const &" for environment objects was broken.
For example, suppose we have a function f that should not modify the input environment.
Before this commit, its signature would be
void f(environment const & env)
This is broken, f's implementation can easilty convert it to a read-write pointer by using
the copy constructor.
environment rw_env(env);
Now, f can use rw_env to update env.
To fix this issue, we now have ro_environment. It is a shared *const* pointer.
We can convert an environment into a ro_environment, but not the other way around.
ro_environment can also be seen as a form of documentation.
For example, now it is clear that type_inferer is not updating the environment, since its constructor takes a ro_environment.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Lean was spending 17% on the runtime "throwing exceptions" in the test tests/lean/implicit7.lean
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Synthesizer is not part of the elaborator anymore.
The elaborator fills the "easy" holes.
The remaining holes are filled using different techniques (e.g., tactic framework) that are independent of the elaborator.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
