struct ExprMacroOutputThe service boundary for expression procedural macros. A successful value carries the already-parsed canonical outcome; Rust adapts it directly and does not parse or lex the materialized source again.
Properties
let source: String
The materialized expression source, empty on failure.
let outcome: ParseOutcome?
The parsed expression result, present only on success.
let metadata: SyntaxMetadataOutput
Identifier provenance and hygiene records for the materialized source.
let failure_code: String?
A stable failure code, when the operation failed.
let failure_message: String?
A human-readable failure description, when the operation failed.
let failure_start: Int
The inclusive starting byte offset of the failure.
let failure_end: Int
The exclusive ending byte offset of the failure.