🤔 Add a type inference engine, along with typed literals. #4

Merged

acw merged 25 commits from refs/pull/4/head into develop

2023-09-19 20:40:05 -07:00

acw commented

2023-08-13 21:09:12 -07:00

(Migrated from gitea.uhsure.com)

The type inference engine is a standard two phase one, in which we first generate a series of type constraints, and then we solve those constraints. In this particular implementation, we actually use a third phase to generate a final AST.

Finally, to increase the amount of testing performed, I've removed the overflow checking in the evaluator. The only thing we now check for is division by zero. This does make things a trace slower in testing, but hopefully we get more coverage this way.

The typed literal formatting mirrors that of Rust. If no type can be inferred for an untagged literal, the type inference engine will warn the user and then assume that they meant an unsigned 64-bit number. (This is slightly inconvenient, because there can be cases in which our Arbitrary instance may generate a unary negation, in which we should assume that it's a signed 64-bit number; we may want to revisit this later.) The type inference engine is a standard two phase one, in which we first generate a series of type constraints, and then we solve those constraints. In this particular implementation, we actually use a third phase to generate a final AST. Finally, to increase the amount of testing performed, I've removed the overflow checking in the evaluator. The only thing we now check for is division by zero. This does make things a trace slower in testing, but hopefully we get more coverage this way.