6. The @document and gathering

How one root schema collects every block instance into a single validated document.

Before you start: Declaring types and decorators

@document marks the root schema. The toolchain *gathers*: every top-level block instance whose kind matches a @child/@children field is collected into that field, and every top-level field must be declared — that is what wcl check checks. Paths like servers.api.port then address the gathered tree from the root.

Document schemas merge per namespace: when several @document types are visible — say a library's (via import <wdoc.wcl>) and your own — a top-level item is legal if any of them declares it. Only a second root-authored @document in the same namespace is an error, so libraries compose without ceremony.

§ 1Exercise: Two kinds, one document

Gather two block kinds under one root and address values through the gathered paths.

@block("server")
type Server {
  @inline(0) name: identifier
  port: u16
}

@block("cache")
type Cache {
  @inline(0) name: identifier
  size_mb: u32
}

@document
type Infra {
  @children("server") servers: list<Server>
  @children("cache")  caches:  list<Cache>
}

server web { port = 8080u16 }
server api { port = 9090u16 }
cache  hot { size_mb = 512u32 }