Concurrency

Clef’s concurrency model is built on delimited continuations. This primitive replaces the colored-function problem of traditional async/await with a single mechanism for suspension, resumption, and structured concurrency.

CCS/Baker settle a region’s dependencies, effects, demand, joint constraints and admitted execution regime on the PSG. Sequential effects use continuation aggregates; admitted independent work may use tensor structure or interaction-net reductions according to its shape and proof premises. Alex’s Library of Alexandria passively witnesses that immutable publication through Huet Elements/Patterns/Witnesses. Composer’s backend owns the selected target realization.

These articles trace how that foundation was chosen and how the compiler lowers async Clef code to native continuations without a managed runtime, from the divergence with .NET’s async lineage to liveness across actor boundaries carried as a visible compile-time obligation. The same reading of a region’s structure decides whether its concurrent strands merely reorder or cross in an order the runtime can observe, the distinction the braid work lifts into the type system.