Function compile

packages/core/src/effect/layer-node.ts:250–272

(
  root: Node<A, E, any>,
  replacements?: ValidReplacements<Items>,
)

}

export function compile<A, E, const Items extends Replacements = readonly []>(
  root: Node<A, E, any>,
  replacements?: ValidReplacements<Items>,
): Layer.Layer<A, E> {
  const replacementMap = replacementMapFrom(replacements)
  const cache = new Map<AnyNode, RuntimeLayer>()
  const compileNode = (node: AnyNode) =>
    walk<RuntimeLayer>(
      node,
      (node, context) => {
        if (node.kind === "unbound") throw new Error(`Unbound layer node: ${node.name}`)
        const dependencies = node.dependencies.flatMap(flatten).map(context.visit)
        const implementation = node.implementation! as RuntimeLayer
        return dependencies.length === 0
          ? implementation
          : implementation.pipe(Layer.provide(dependencies as [RuntimeLayer, ...RuntimeLayer[]]))
      },
      { cache, resolve: (node) => replacementMap.get(node.name) ?? node },
    )
  const layers = flatten(root).map((node) => compileNode(node))
  const layer = layers.reduce<RuntimeLayer>((result, layer) => layer.pipe(Layer.provideMerge(result)), Layer.empty)
  return layer as Layer.Layer<A, E>
}

function replacementMapFrom(replacements?: Replacements) {
  return (