# Upstream provenance

MoonCEL targets `cel-expr/cel-spec` release `v0.25.3` at commit
`ba58ae5007845f3a1279b488cdeb79645ce958bb`.

- Source: <https://github.com/cel-expr/cel-spec/tree/v0.25.3>
- Release: <https://github.com/cel-expr/cel-spec/releases/tag/v0.25.3>
- Upstream license: Apache License 2.0
- Local reference checkout: `../references/cel-spec-v0.25.3` (development
  evidence only; it is not copied into this package)

## Adapted scope

Tests were independently expressed in MoonBit for the v0.1-supported language
surface: lexical escapes and numeric forms, operator precedence, collections,
field/index access, gradual checking, lazy logic, standard macro scope,
integer boundaries, and bounded evaluation. No upstream source file or test
suite is vendored into the distributable package.

The implementation follows the syntax and semantic descriptions in the CEL
language definition and tests the supported subset using MoonBit-native named
tests. Where v0.1 intentionally differs, README's compatibility matrix is the
normative project statement.

## Explicit conformance skips

The following upstream families are not counted as passing:

- protobuf message construction, field presence on protobuf descriptors, Any,
  wrappers, serialization, and protobuf-specific equality;
- timestamp and duration parsing/arithmetic;
- optional types and extension-library behaviors;
- policy YAML/configuration layers;
- complete RE2 syntax and behavior;
- official wire-format conformance harness integration;
- implementation-specific extension functions outside the documented v0.1
  standard environment.

These are roadmap items or deliberate non-goals, not silent successes.

## Name and trademark note

Common Expression Language and CEL identify the upstream specification.
MoonCEL is an independent implementation and is not presented as an official
CEL project release.