Contributions, productions and assembly

A resource is reusable code/data authority. A contribution describes one kind of insertion. A live build instance has a name/index within the assembly. Sharing a resource does not mean sharing a live instance identity.

Field	Meaning	Tutorial value
Resource name	Reusable authored snippet	Parameter
Contribution name	Binding/placement declaration	Param
as	Live build name	Param
index	Numeric instance index	(ClassOrder, FieldOrder)
order	Insertion ordering	FieldOrder
target hole	Receiving surface	params
build path	Build to locate	/InitMethod
ident	Identifier demand binding	field_name = FieldName
external	External literal/path binding	slot = FieldName

Index accepts int, tuple of ints, or no index. A string collection identity is not a valid build index. Orders and paths are evaluated from the current data stack. Keep collection identity, owner relationship, index and order distinct. Explicit numeric composites avoid repeated-field collisions across owners.

Nested roots and addressing

ModuleProduction builds /Root, then class production contributions establish /ClassDef. InitProduction establishes /InitMethod; its field contributions target local mapped roots. A flat absolute-looking path is evaluated within the current production/root mapping. For indexed siblings use the actual evaluated index, as demonstrated by yidl_update_a_scope_paths.py.

The grammar allows target build and owner constraints, indexed segments and selector segments. Accepted path syntax does not prove a destination exists. A missing build, unresolved binding and wrong owner can produce different cause chains. Low-level selector helpers are diagnostic tools, not a universal build trace API.

Order and empty behavior

Productions apply their declared edges/phases. Contributions carry independent insertion order; root names and index identities must not collide. An empty-source resource is suppressed. No match supplies nothing. Neither automatically fills a mandatory hole. Explicit empty parameter payloads and pass statements fill the tutorial's mandatory holes even for zero fields/disabled init.

An assembly Name = Production declaration produces build_Name in the emitted runtime. export concept controls import visibility; it does not by itself name all assembly functions. Diagnostic contributions fail explicitly with selected messages instead of generating code. Debugging shows how to inspect available builders and metadata.

Nested indexed expression propagation from D17 remains unresolved. Do not infer support for that arrangement from successful nested class/method productions.