James Clark

Representation for mapping atoms that can handle intersection and difference

6

Section 9.1.4 (page 177) if the [Frisch thesis](http://www.cduce.org/papers/frisch_phd.pdf) has a way of representing records that can represent intersection and difference. There is a mentioned in footnote 29 of the April...

Type-emptiness testing should produce witness

1

In a case where a type S is expected to be a subtype of type T, we test whether the set difference of S and T is empty, and then...

Following #993, I believe we need to consider N distinct labels that do not occur in the positives or negatives where N is the number of negatives, since for each...

Do not create unnecessary narrowing for sequence of statements

1

Given something like: ``` if x == 1 { foo(); } else { bar(); } baz(x); ``` the type for x in `baz` is the union of it's narrowed types...

Since a mapping can be a subtype of a closed record type (i.e. a type with a rest type is never) only if it is also a closed record type...

Following on from #575, this is a tracking issue for possible optimizations of the implementation of int subtypes - [x] #169 (this is for exactly bytes) - [x] #890 -...

Use indexed get/set with open records when reference is exact

3

At the moment we use an indexed get/set (bypassing hash table lookup) when we have a closed record. We can also do it for an open record when the exact...

Implement `match` patterns

1

This builds on #256. Given we now have `map` and `any[]`, we can now implement match-patterns, specifically - list-match-pattern - mapping-match-pattern We would initially have the restriction that a binding-pattern...

Support multiple diagnostic messages per compilation

8

nballerina currently has a very limited approach to error handling: it reports one error per compilation. We need to evolve this into something more functional.

We can generate better code for two arrays that are subtypes of `int[]` by using the get_int vtable member to access the members. This will avoid a lot of memory...