Commit graph

24 commits

Author SHA1 Message Date
Leonardo de Moura
d69db172a1 chore(kernel/replace_fn): add syntax sugar for replace function
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-07-19 12:53:37 +01:00
Leonardo de Moura
cb000eda13 refactor(kernel): store binder_infor in local constants
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-06-30 11:37:46 -07:00
Leonardo de Moura
603dafbaf7 refactor(kernel): remove 'let'-expressions
We simulate it in the following way:
1- An opaque 'let'-expressions (let x : t := v in b) is encoded as
      ((fun (x : t), b) v)
   We also use a macro (let-macro) to mark this pattern.
   Thus, the pretty-printer knows how to display it correctly.

2- Transparent 'let'-expressions are eagerly expanded by the parser.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-06-24 16:27:27 -07:00
Leonardo de Moura
1c5d3295cc refactor(library/deep_copy): use replace to implement deep_copy
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-06-11 14:35:34 -07:00
Leonardo de Moura
4a25e7442a feat(kernel/expr): add optional expression caching (aka "partial" hash-consing)
We do not enforce full hash-consing because we would need to synchronize
the access to the hashtable/cache.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-06-03 15:35:47 -07:00
Leonardo de Moura
33ae79cd9e refactor(kernel): move shallow copy function to library
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-05-17 11:20:24 -07:00
Leonardo de Moura
862c5e354d feat(kernel/expr): attach auxiliary name (for pretty printing) into local constants
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-05-16 13:08:09 -07:00
Leonardo de Moura
40b3129e7b refactor(kernel): improve names
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-05-16 11:28:05 -07:00
Leonardo de Moura
bc8379256a refactor(kernel): remove pairs from kernel
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-04-17 10:52:07 -07:00
Leonardo de Moura
8cd78e00f1 refactor(library): deep_copy procedure
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-03-18 10:27:56 -07:00
Leonardo de Moura
6d7ec9d7b6 refactor(kernel): add heterogeneous equality back to expr
The main motivation is that we will be able to move equalities between universes.

For example, suppose we have
    A : (Type i)
    B : (Type i)
    H : @eq (Type j) A B
where j > i

We didn't find any trick for deducing (@eq (Type i) A B) from H.
Before this commit, heterogeneous equality as a constant with type

   heq : {A B : (Type U)} : A -> B -> Bool

So, from H, we would only be able to deduce

   (@heq (Type j) (Type j) A B)

Not being able to move the equality back to a smaller universe is
problematic in several cases. I list some instances in the end of the commit message.

With this commit, Heterogeneous equality is a special kind of expression.
It is not a constant anymore. From H, we can deduce

   H1 : A == B

That is, we are essentially "erasing" the universes when we move to heterogeneous equality.
Now, since A and B have (Type i), we can deduce (@eq (Type i) A B) from H1. The proof term is

  (to_eq (Type i) A B (to_heq (Type j) A B H))  :  (@eq (Type i) A B)

So, it remains to explain why we need this feature.

For example, suppose we want to state the Pi extensionality axiom.

axiom hpiext {A A' : (Type U)} {B : A → (Type U)} {B' : A' → (Type U)} :
      A = A' → (∀ x x', x == x' → B x == B' x') → (∀ x, B x) == (∀ x, B' x)

This axiom produces an "inflated" equality at (Type U) when we treat heterogeneous
equality as a constant. The conclusion

     (∀ x, B x) == (∀ x, B' x)

is syntax sugar for

   (@heq (Type U) (Type U) (∀ x : A, B x) (∀ x : A', B' x))

Even if A, A', B, B' live in a much smaller universe.

As I described above, it doesn't seem to be a way to move this equality back to a smaller universe.

So, if we wanted to keep the heterogeneous equality as a constant, it seems we would
have to support axiom schemas. That is, hpiext would be parametrized by the universes where
A, A', B and B'. Another possibility would be to have universe polymorphism like Agda.
None of the solutions seem attractive.

So, we decided to have heterogeneous equality as a special kind of expression.
And use the trick above to move equalities back to the right universe.

BTW, the parser is not creating the new heterogeneous equalities yet.
Moreover, kernel.lean still contains a constant name heq2 that is the heterogeneous
equality as a constant.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-02-07 10:28:10 -08:00
Leonardo de Moura
8eec289ce1 feat(kernel): add dependent pairs
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-02-03 16:52:49 -08:00
Leonardo de Moura
a43020b31b refactor(kernel): remove heterogeneous equality
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-16 17:39:12 -08:00
Leonardo de Moura
411f14415d feat(builtin): automatically generate Lean/C++ interface for builtin theories
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-09 18:09:53 -08:00
Leonardo de Moura
2f88d6710c feat(kernel/expr): add some_expr and none_expr for building values of type optional<expr>
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-12-08 10:34:38 -08:00
Leonardo de Moura
3e1fd06903 refactor(kernel/expr): remove 'null' expression, and operator bool for expression
After this commit, a value of type 'expr' cannot be a reference to nullptr.
This commit also fixes several bugs due to the use of 'null' expressions.

TODO: do the same for kernel objects, sexprs, etc.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-12-07 23:21:10 -08:00
Leonardo de Moura
92f5a31976 feat(kernel/expr): add new mk_app template for creating applications using a collection
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-10-27 08:53:58 -07:00
Leonardo de Moura
59914a36f3 refactor(metavar): reorganize and simplify metavariables
- Use hierarchical names instead of unsigned integers to identify metavariables.
- Associate type with metavariable.
- Replace metavar_env with substitution.
- Rename meta_ctx --> local_ctx
- Rename meta_entry --> local_entry
- Disable old elaborator
- Rename unification_problems to unification_constraints
- Add metavar_generator
- Fix metavar unit tests
- Modify type checker to use metavar_generator
- Fix placeholder module

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-10-22 08:15:36 -07:00
Leonardo de Moura
e16f45854b refactor(deep_copy): simplify deep_copy implementation, and move unit test to separate file
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-25 20:25:24 -07:00
Leonardo de Moura
99a163f11d Simplify metavariable context. Now, we have only 'lift' and 'inst' instead of 'subst', 'lift' and 'lower'
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-16 19:32:28 -07:00
Leonardo de Moura
63e102055e Move metavariables to the kernel. This is the first step for implementing the new elaborator.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-15 12:09:01 -07:00
Leonardo de Moura
26097475fd Use fullpath in #include directives.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-12 20:04:10 -07:00
Leonardo de Moura
2459c4ae7c Add (optional) type to let declarations
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-06 10:06:26 -07:00
Leonardo de Moura
0f6a7e4a95 Rename exprlib to library. Name was misleading, it is more than a library for manipulating expressions.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-08-22 10:26:52 -07:00
Renamed from src/exprlib/deep_copy.cpp (Browse further)