Discussions related to nkError

[saem]

This discussion catalogs the various bits related to the nkError project. Likely mostly design things.

[saem]

In regards to exposing nkError in the macros API, it's presently undocumented and whatever that will be done in the interim will be unstable. During a chat with @disruptek we realize that we need an intermediate step however.

overview

This is a summary of module comments.

Node structure:

• First node is the AST it swapped, though at some points in the compiler that's off, those are bugs to fix mostly induced by design.
• Second is the error kind itself as int lit.
• Third is compiler instantiation info as str lit.
• Then everything else is varargs nodes to be interrupted by error kind.

Routines:

• There are convenience constructors, to string, and traversal iterators.

what we could do

So the progression of what we can allow is something like:

• for now see an nkError and macros should eject
• see an nkError and allow them to recover
• see an error and let them elaborate (construct)
• etc

additional considerations

Finally, symbol and type also have error variants.

API instability

Source of instability in all this is that the error node might get changed with a specialized representation, mostly invisible except fewer lit nodes. Additional error metadata for more structured errors. Symbol and type errors are a whole different beast.