Instead of constantly making these updates, let's just remove the year
since things are stored in git anyways, and this is not an actual modern
legal risk anymore.
This adds a modern type unification algorithm, which drastically
improves performance, particularly for bigger programs.
This required a change to the AST to add TypeCheck methods (for Stmt)
and Infer/Check methods (for Expr). This also changed how the functions
express their invariants, and as a result this was changed as well.
This greatly improves the way we express these invariants, and as a
result it makes adding new polymorphic functions significantly easier.
This also makes error output for the user a lot better in pretty much
all scenarios.
The one downside of this patch is that a good chunk of it is merged in
this giant single commit since it was hard to do it step-wise. That's
not the end of the world.
This couldn't be done without the guidance of Sam who helped me in
explaining, debugging, and writing all the sneaky algorithmic parts and
much more. Thanks again Sam!
Co-authored-by: Samuel Gélineau <gelisam@gmail.com>
With the recent merging of embedded package imports and the entry CLI
package, it is now possible for users to build in mcl code into a single
binary. This additional permission makes it explicitly clear that this
is permitted to make it easier for those users. The condition is phrased
so that the terms can be "patched" by the original author if it's
necessary for the project. For example, if the name of the language
(mcl) changes, has a differently named new version, someone finds a
phrasing improvement or a legal loophole, or for some other
reasonable circumstance. Now go write some beautiful embedded tools!
This adds ExprTopLevel and ExprSingleton and ensures that ExprBind is
now monomorphic.
This corrects a previous design bug where it was not monomorphic and
would thus cause spawning of many more copies than necessary. In most
cases this was only harmful to memory and performance, and not
behaviour, since these functions were pure, and we didn't have a test
for this.
This also adds a bunch more tests. Most notably, the graph shape tests
generally produce smaller graphs now.
Lastly, a lambda cannot have two different types when used at two
different call sites. It is rare that this would be used, and when it
would make sense, there are easy workarounds to accomplish equivalent
goals.
This was mostly authored by Sam, James helped with some cleanup and
debugging.
Co-authored-by: James Shubin <james@shubin.ca>
This is a big giant patch that implements the AST part of lambdas!
I don't know how Sam is able to understand the AST so well, but he does,
and we're all grateful for it. Most of this code was written by him.
Co-authored-by: Samuel Gélineau <gelisam@gmail.com>
This will probably change up again in the future, but this is what we
need for now to make lambdas work.
Co-authored-by: Samuel Gélineau <gelisam@gmail.com>
This is a giant refactor to split the giant lang package into many
subpackages. The most difficult piece was figuring out how to extract
the extra ast structs into their own package, because they needed to
call two functions which also needed to import the ast.
The solution was to separate out those functions into their own
packages, and to pass them into the ast at the root when they're needed,
and to let the relevant ast portions call a handle.
This isn't terribly ugly because we already had a giant data struct
woven through the ast.
The bad part is rebasing any WIP work on top of this.
