PreviewExport

Property delegate (ReadOnlyProperty<Any?, Sequence<CollectedPreview>>) used as the backing field type for properties declared with val x by collectModulePreviews() / collectAllModulePreviews(). Reading the property yields the underlying Sequence<CollectedPreview> directly, so consumers iterate the sequence with the standard kotlin.sequences operators (firstOrNull { ... }, take(N).toList(), toList(), …) without going through any wrapper accessor.

The sequence is wrapped in a Lazy so that the per-@Preview factory lambdas the compiler plugin emits are not invoked until the property is first read; iterating the sequence then lazily constructs each CollectedPreview on demand. Consumers that only need the first few entries (e.g. a search filter that returns 10 hits out of thousands of @Preview declarations) avoid materializing the rest, dropping peak memory usage on large preview corpora.

Cross-module preview discovery does not rely on this type — it is handled by the compiler plugin emitting per-@Preview hint functions (previewHint_<scope>(value: PreviewHintMarker_<hash>?): CollectedPreview in the me.tbsten.compose.preview.lab.hints package) that the consumer side resolves through IrPluginContext.referenceFunctions.

Users do not construct this class directly — it is produced exclusively by the compiler plugin.

Usage:

// delegated property; type is `Sequence<CollectedPreview>`
val myPreviews by collectModulePreviews()

// eager: drains the sequence to a list (used by Gallery, integration tests, etc.)
myPreviews.toList()

// lazy: walk in order, stop early
myPreviews.firstOrNull { it.id == targetId }
myPreviews.take(10).toList()

See also