Show HN: CEL by Example
6 days ago
- #Data Processing
- #Expression Language
- #CEL
- CEL (Common Expression Language) evaluates expressions against data like simple values, Protobuf messages, or JSON objects.
- CEL is fast, portable, and safe, used in Kubernetes, Google Cloud IAM, Firebase security, Envoy Proxy, and Protovalidate.
- Basic comparisons in CEL include checking user age and email domains.
- Collections in CEL can be checked for membership with 'in' and filtered with 'filter()'.
- Timestamps and durations in CEL allow checking time-based conditions like email verification within 24 hours.
- Logical operators in CEL combine checks into single expressions and allow branching logic.
- CEL can transform data, such as stripping PII or annotating roles.
- The 'map()' function in CEL transforms collections, filters, and applies conditions in one step.