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Comment by zdimension | Hacker News Reader

When reading code in a low level setting you may want to know whether one line calls a function or simply reads a field from memory. Not that it would matter that much, but it's a valid point for some. Reading a field is usually expected to not induce any control flow

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> When reading code in a low level setting you may want to know whether one line calls a function or simply reads a field from memory.

Unless you ditch optimizations completely, it is hard to know without looking at the generated asm. Of course you can make educated guesses.

The idea in D is to make the following unnecessary:

    struct S {
        int m_field;
        int field() { return m_field; }
        void field(int c) { m_field = x; }
    }

just to future proof the field access. Don't bother with the access functions until they are actually needed.

The actual feature that languages should implement is lenses, prisms and optics which are like properties except made properly composable and enabling high-level optimizations, for a similar efficiency to "bare" field access.

I’ve never heard of those. Do you have a link explaining them?

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