Handles are the Better Pointers

Oct 20, 2023


Describes the pattern of programs with subsystems that give out integer handles, which represent indexes into internal arrays, rather than allowing allocations all over the place.

Gives some good explanation of the rules to put in place if you adopt this pattern, and how to avoid dangling handles.

via responses to this tweet

Compiler people like to use arenas a lot: like, where you pack an expression tree into an array and use plain ol’ integer offsets instead of pointers to refer to nodes in the tree. The benefits are many: less allocation, smaller references, better locality, easier to think about lifetimes.

But I’ve never seen this technique taught in a class. Does anybody know of basic resources that explain the idea? Maybe I should add it to my compilers curriculum, even though it’s not a compiler-specific idea at all?

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