Spanda combines compile-time contracts with runtime enforcement for autonomous systems.
| Feature | Syntax | Status |
|---|---|---|
| Periodic tasks | task … every Nms |
Stable |
| Deadlines | deadline Nms on tasks |
Stable |
| Jitter bounds | jitter <= Nms |
Stable |
| Resource budgets | budget { cpu <= … } |
Stable |
| Pipelines | pipeline name budget Nms { … } |
Stable |
| Watchdogs | watchdog Name timeout Nms { … } |
Stable |
| Recovery | recover from Error { … } |
Stable |
| Retry/fallback | retry N times backoff Nms { … } fallback { … } |
Parsed; runtime policy partial |
| Operating modes | mode name { … } |
Stable |
Invalid timing and regex patterns produce line/column diagnostics with suggested fixes, for example:
deadline (20ms) must be <= period (10ms)Invalid regex syntax: …Watchdog 'W' target task 'Missing' not found
Recovery from RuntimeError should stop actuators or enter a degraded mode. The type checker warns
when recovery blocks omit these actions.
See realtime and degraded-modes.