JuliaLowering

Goals

Trying it out

Design notes

Syntax trees

References

Structural assertions / checking validity of syntax trees

Provenance tracking

Problems with Hygiene in Julia's exiting macro system

Hygiene References

Overview of lowering passes

Pass 1: Macro expansion

Hygiene in JuliaLowering

Compatibility with `Expr` macros

Pass 2: Syntax desugaring

Desugaring of function definitions

Desugaring of generated functions

Pass 3: Scope analysis / binding resolution

Pass 4: Closure conversion / lower bindings

Q&A

When does `function` introduce a closure?

How do captures work with non-closures?

How do captures work with closures with multiple methods?

When are `method` defs lifted to top level?

Pass 5: Convert to untyped IR

Untyped IR (JuliaLowering form)

Lowering of exception handlers

Lowering finally code paths

Pass 6: Convert IR to `CodeInfo` representation

Untyped IR (`CodeInfo` form)

Notes on toplevel-only forms and eval-related functions

Bugs in Julia's lowering

Notes on Racket's hygiene