$ cue help experiments
Experimental features that can be enabled in CUE.

There are two types of experiments:

1. Per-file experiments: Enabled via @experiment attribute in CUE files
2. Global experiments: Enabled via the CUE_EXPERIMENT environment variable

## Per-file Experiments

Experiments are enabled in CUE files using file-level attributes:

	@experiment(structcmp)

	package mypackage

	// experiment is now active for this file

Multiple experiments can be enabled:

	@experiment(structcmp,self)
	@experiment(explicitopen)

Available per-file experiments:

  structcmp (preview: v0.14.0, stable: v0.15.0)
    structcmp enables comparison of structs. This also defines the ==
    operator to be defined on all values. For instance, comparing 1 and
    "foo" will return false, whereas previously it would return an error.
    Proposal:      https://cuelang.org/issue/2583
    Spec change:   https://cuelang.org/cl/1217013
    Spec change:   https://cuelang.org/cl/1217014

  explicitopen (preview: v0.15.0)
    explicitopen enables the postfix ... operator to explicitly open
    closed structs, allowing additional fields to be added.
    Proposal:      https://cuelang.org/issue/4032
    Spec change:   https://cuelang.org/cl/1221642
    Requires cue fix when upgrading

  self (preview: v0.15.0)
    self enables the use of 'self' identifier to refer to the enclosing struct.
    Proposal:      https://cuelang.org/issue/4014
    Spec change:   https://cuelang.org/cl/1222377


## Global Experiments

Global experiments are enabled via the CUE_EXPERIMENT environment variable:

	export CUE_EXPERIMENT=cmdreferencepkg,keepvalidators
	cue export myfile.cue

Available global experiments:

  cmdreferencepkg (preview: v0.13.0, default: v0.14.0)
    cmdreferencepkg requires referencing an imported tool package to declare tasks.
    Otherwise, declaring tasks via "$id" or "kind" string fields is allowed.

  decodeint64 (preview: v0.11.0, default: v0.12.0, stable: v0.13.0)
    decodeint64 changes [cuelang.org/go/cue.Value.Decode] to choose
    'int64' rather than 'int' as the default type for CUE integer values
    to ensure consistency with 32-bit platforms.

  embed (preview: v0.10.0, default: v0.12.0, stable: v0.14.0)
    embed enables support for embedded data files as described in
    https://cuelang.org/discussion/3264.

  evalv3 (preview: v0.9.0, default: v0.13.0, stable: v0.15.0)
    evalv3 enables the new CUE evaluator, addressing performance issues
    and bringing better algorithms for disjunctions, closedness, and cycles.

  keepvalidators (preview: v0.14.0, default: v0.14.0, stable: v0.15.0)
    keepvalidators prevents validators from simplifying into concrete values,
    even if their concrete value could be derived, such as '>=1 & <=1' to '1'.
    Proposal:     https://cuelang.org/discussion/3775.
    Spec change:  https://cuelang.org/cl/1217013
    Spec change:  https://cuelang.org/cl/1217014

  modules (preview: v0.8.0, default: v0.9.0, stable: v0.11.0)
    modules enables support for the modules and package management proposal
    as described in https://cuelang.org/discussion/2939.

  toposort (preview: v0.11.0, default: v0.12.0, stable: v0.14.0)
    toposort enables topological sorting of struct fields.
    Provide feedback via https://cuelang.org/issue/3558.

  yamlv3decoder (preview: v0.9.0, default: v0.9.0, stable: v0.11.0)
    yamlv3decoder swaps the old internal/third_party/yaml decoder with the new
    decoder implemented in internal/encoding/yaml on top of yaml.v3.

Experiment lifecycle:
- preview:   experimental feature that can be enabled
- default:   experiment enabled by default, can still be disabled
- stable:    experiment permanently enabled, experiment flag has no effect
- withdrawn: experiment removed and permanently disabled

Language experiments may change behavior, syntax, or semantics.
Use with caution in production code.