path: root/linux/300.txt

                                                                              
                                                                            
Layers in the 3xx series use all the available syntax sugar for SubX programs.
Functions here can be called from Mu programs if they meet certain criteria:

  - There's a signature for them in 400.mu
  - Inouts on the stack, outputs in registers
  - Valid Mu types everywhere (Mu's type system isn't expressive enough for
    everything SubX does in rare situations.)
  - No way to for an `addr` to escape a function. No `(... addr ... addr ...)`
    inouts, and no `(... addr ...)` outputs.

While functions _can_ be called, not all SubX functions meeting these criteria
_should_ be called. In particular, avoid exporting functions that could be
misused. A classic example is trying to add a `size-of` operator. If you're
doing that you're likely going to rely on programmers to use it correctly. Mu
tries to be idiot-proof. Even if SubX requires greater care, using SubX
primitives from Mu should not.
Layers in the 3xx series use all the available syntax sugar for SubX programs.
Functions here can be called from Mu programs if they meet certain criteria:

  - There's a signature for them in 400.mu
  - Inouts on the stack, outputs in registers
  - Valid Mu types everywhere (Mu's type system isn't expressive enough for
    everything SubX does in rare situations.)
  - No way to for an `addr` to escape a function. No `(... addr ... addr ...)`
    inouts, and no `(... addr ...)` outputs.

While functions _can_ be called, not all SubX functions meeting these criteria
_should_ be called. In particular, avoid exporting functions that could be
misused. A classic example is trying to add a `size-of` operator. If you're
doing that you're likely going to rely on programmers to use it correctly. Mu
tries to be idiot-proof. Even if SubX requires greater care, using SubX
primitives from Mu should not.