Module stub 

The C2 reduction stub: the one shared format/parse module every placeholder-emitting reduction (A7-A10, and any future kind) goes through.

Normative grammar (D2, merging A4 + C2):

[sc-reduced <kind> <id>: <summary>]

• Plain ASCII so the line survives conversion through any harness format without escaping.
• <kind> is one of the strings below (mirrors super::ReductionKind).
• <id> matches r\d{4}-[0-9a-f]{4} (see super::make_id).
• <summary> is one line and contains no ].

Enums

Kind

The stub <kind> token: the wire vocabulary for ReductionKind, kept as its own type because the grammar’s kind strings are a stable contract independent of the enum’s Rust variant names or field shapes.

Functions

format

Format a reduction stub line: [sc-reduced <kind> <id>: <summary>].

parse

Parse a reduction stub line back into (kind, id, summary).