🚀 go-pugleaf

byatesiii@my-deja.com wrote:
[variant records]
> Your 2nd example allows a person to store either two words or four
> bytes (same size) within the record, and Pascal chooses which one by
> the type of the data you are storing there (byte or word).
> In some implementations I think the size of each variant had to be the
> same, or the larger ones came first. Your first example doesn't appear
> to follow this restriction. But then again, I'm a UCSD Pascal
> programmer... the only one left, I imagine :)

Variant records can have variants of different sizes; enough space is
allocated to store the largest. The type used is determined when the data is
read or written; this makes it easy to convert data between compatible 
types.  For instance, TP has a variant record type for the registers; so you
can store data in the 8-bit registers and read it from the 16-bit registers,
or the other way around. Many other applications are possible. In
particular, it makes it possible to pass different but related types to a
single procedure or function, as in your polygon example. Each form needs
its own parameters and storage, but a single routine can handle them by
using the variant record.

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