Monthly Archives: July 2018

Lifetime crisis

This is one of such embarrassing moments when I have to admit that because of lack of proper design I fell into trouble. I’ve been recently working on adding lifetime checks to Skila and I found more problems than expected.

let iter = coll.getIterator();

This benign piece killed the idea of not adding any new features — I already have pointers and references, but since collection can be on stack or on heap I would need to add something in between. A pointer with limited lifetime — this way I could tie up coll with iter — if it is regular pointer with global lifetime, go ahead be global. But if not — iterator needs to be local.

Or I could perform boxing on fly… C# has this feature and I hate it — it is difficult to see with naked eye performance offending code.

let elem = coll[index];
coll.clear();

I use references with indexer so this would lead to cherished undefined behavior. The easiest way would be to change semantics and working with values, two other approaches would require reworking entire language — I could go Rust way with ownership or functional way with immutable data (collection could not be altered, thus all references would be guaranteed to be valid).

foreach (let elem in coll)
  coll.clear();

Here Rust simply shines detecting the problem in compile time. This is the least problematic piece though, because one way or another it will always work correctly, maybe only surprisingly.

Honestly those problems undermine entire Skila existence — I wanted to get easy, likeable yet performant language. And I don’t see it on the horizon.

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