Module resolver 

Schema resolver and merge engine.

The SchemaResolver implements a five-level priority chain for determining the Arrow schema of a source connector:

1. Full DDL — user-declared schema without wildcards
2. Schema registry — via SchemaRegistryAware
3. Source provider — via SchemaProvider
4. Sample inference — via SchemaInferable
5. Error — no schema could be determined

When partial DDL is provided (with wildcard *), the resolver merges user-declared columns with the resolved columns, preserving user-declared columns first.

Structs

DeclaredColumn

A single column declared in DDL.

DeclaredSchema

A user-declared schema from DDL (e.g., CREATE SOURCE ... (col1 INT, ...)).

ResolvedSchema

The result of schema resolution.

SchemaResolver

Stateless schema resolver.

Enums

FieldOrigin

Origin of a single field in a resolved schema.

ResolutionKind

How the schema was resolved.