18 lines
947 B
Plaintext
18 lines
947 B
Plaintext
Layers in the 3xx series use all the available syntax sugar for SubX programs.
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They're used by the Mu translator (apps/mu.subx) and can also be called from
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Mu programs if they meet certain criteria:
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- There's a signature for them in 400.mu
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- Inouts on the stack, outputs in registers
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- Valid Mu types everywhere (Mu's type system isn't expressive enough for
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everything SubX does in rare situations.)
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- No way to for an `addr` to escape a function. No `(... addr ... addr ...)`
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inouts, and no `(... addr ...)` outputs.
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While functions _can_ be called, not all SubX functions meeting these criteria
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_should_ be called. In particular, avoid exporting functions that could be
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misused. A classic example is trying to add a `size-of` operator. If you're
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doing that you're likely going to rely on programmers to use it correctly. Mu
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tries to be idiot-proof. Even if SubX requires greater care, using SubX
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primitives from Mu should not.
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