Function parse_schema_diagnostics 

pub fn parse_schema_diagnostics(
    path: &str,
    source: &str,
) -> (Option<Schema>, Vec<SchemaError>)

Parse and validate, reporting every independent problem rather than only the first.

parse_schema_named stops at the first error, which is right for a compiler or a CLI: the build is failing either way, and one clear message beats a cascade. It is wrong for an editor, where stopping early means the author fixes one error, saves, and is handed the next — one round trip per mistake.

Semantics worth knowing:

• A syntax error still yields exactly one diagnostic. Parsing has no recovery, so there is no second error to report — everything after the failure is unparsed, not valid.
• Validation errors are collected in stages, and a stage runs only when every earlier stage was clean. Several validators document that they assume an earlier one passed, and running them over already-rejected input produces cascades pointing at the wrong places. Within a stage, every declaration reports independently — three models each naming a type that does not exist produce three diagnostics, not three round trips.
• The schema is returned only when there are no errors at all, matching parse_schema_named.

The first element of the returned Vec is always the same error parse_schema_named would have returned; both go through one set of checks in one order, so they cannot drift apart.