This implements a new type of syntactic sugar for the common pattern of
a base class which returns a child class, and so on. Instead of needing
to repeatedly indent the child classes, we can instead prefix them at
the definition site (where created with the class keyword) with the name
of the parent class, followed by a colon, to get the desired embedded
sugar.
For example, instead of writing:
class base() {
class inner() {
class deepest() {
}
}
}
You can instead write:
class base() {
}
class base:inner() {
}
class base:inner:deepest() {
}
Of course, you can only access any of the inner classes by first
including (with the include keyword) a parent class, and then
subsequently including the inner one.
This adds support for `include as <identifier>` type statements which in
addition to pulling in any defined resources, it also makes the contents
of the scope of the class available to the scope of the include
statement, but prefixed by the identifier specified.
This makes passing data between scopes much more powerful, and it also
allows classes to return useful classes for subsequent use.
This also improves the SetScope procedure and adds to the Ordering
stage. It's unclear if the current Ordering stage can handle all code,
or if there exist corner-cases which are valid code, but which would
produce a wrong or imprecise topological sort.
Some extraneous scoping bugs still exist, which expose certain variables
that we should not depend on in future code.
Co-authored-by: Samuel Gélineau <gelisam@gmail.com>
This is a newer implementation of the panic magic. I kept the old commit
in for posterity and to show the difference. The two versions are
identical to the end-user with one exception: the newer version doesn't
include a useless panic resource in the graph when there is no panic. In
this version, the panic function returns false and the if statement it's
the condition of, doesn't produce the resource within. On error, we
still consume the function in the if expression, and doing so causes
everything to shutdown.
The other benefit is that the implementation is much cleaner and doesn't
need the interpolate hack.
It's valuable to check your runtime values and to shut down the entire
engine in case something doesn't match. This patch adds some magic
plumbing to support a "panic" mechanism.
A new "panic" statement gets transparently converted into a panic
function and panic resource. The former errors if the input is not
empty. The latter must be present to consume the value, but doesn't
actually do anything.
This seems to make things work. I'm worried I might have an ordering bug
where we might choose the wrong precedence if we write ambiguous code
somehow, but at least for now, let's commit this and move on. Hopefully
the nonassoc stuff is actually correct.
Instead of in the lexer. I think this simplifies things and gives the
parser more information which should hopefully make it easier to parse
without shift/reduce conflicts.
It's a normally named function for now, until we think of a common
package to move it into.
Hopefully this makes improving the lexer and parser easier for now. We
can consider bringing it back if needed.
There were a bunch of packages that weren't well documented. With the
recent split up of the lang package, I figured it would be more helpful
for new contributors who want to learn the structure of the project.
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.
