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Wave 3 — Rich Types, Async & Concurrency

Wave 3 introduced modern structural data types and consolidated Aipo's deterministic, cooperative asynchronous concurrency infrastructure.

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Achieved Milestones

1. Rich Types and Value Semantics

• Set: Collection of unique values maintaining strict insertion order.
• Sequence: Lazy evaluation pipelines enabling composable data transformations without intermediate allocations.
• Bytes Packing: Direct binary reading and writing methods (read_u16_le, write_u32_be, etc.), optimized for binary protocols and high-throughput I/O.
• Duration: Native type for high-precision time intervals.

2. Asynchronous Syntax & Semantics

• Functions declared with async fn return cooperative task handles.
• Sequential await do ... end block prevents scattered await expressions across nested operations, eliminating subtle interleaving race conditions.
• Static semantic diagnostics:
  • AIPO_SEM_AWAIT_IN_SUBEXPRESSION: Disallows unanchored await outside dedicated blocks.
  • AIPO_SEM_FORGOTTEN_TASK: Flags unawaited, detached task handles.
  • AIPO_SEM_NESTED_AWAIT_DO: Forbids confusing nested await blocks.

3. Cooperative Scheduler with Virtual Time

• Deterministic runtime task scheduler:
  • Tasks yield execution cooperatively at explicit suspension boundaries (task.sleep, await).
  • Runtime execution does not depend on host wall-clock time, but on a deterministic virtual clock, enabling tests with multiple timeouts to execute in milliseconds with zero test flakiness.

4. Async Combinators & Cycle Detection

• Full task standard library: task.spawn, task.sleep, task.all, task.race, task.timeout, task.cancel, task.group.
• Runtime cycle detection across transitive task await chains (AIPO_RT_AWAIT_CYCLE), preventing silent task deadlocks.