Documentation

Guides, reference and evidence

Every page here is the markdown from twill-lang/twill, rendered at build time. There is no second copy to go stale.

Start here

TutorialFrom nothing to a trained model.

Language guideThe reference: syntax, tensors, shapes, units, the builtins.

ExercisesProblems to work through, with answers in the repo.

Reference

Type systemHow shapes, units and records are checked before anything runs.

Data typesThe numeric tower, and what each type costs.

The CLIrun, check, fmt, test, repl, and why they are shaped that way.

Under the hood

Design notesWhy it is built this way, and the roadmap.

Self-hostingThe systems subset, and the compiler written in twill.

What the language still needsThe work queue, one numbered entry per missing feature.

DecisionsThe calls that were made, and what they cost.

GPU feasibilityWhat a GPU backend would actually buy, measured.

Financial MLWhere twill aims to beat a Python stack, assessed honestly.

Evidence

CorrectnessThe evidence for grad and for the checker.

BenchmarksHow fast it is, where the time goes, and PyTorch on the same mathematics.