feature: enumerated type with explicit ordinal values

• Type: feature (Track A — parser)
• Status: done
• Found: 2026-06-23, differential probe vs FPC
• Severity: low-medium (common for C-interop / protocol constants)

Gap

Assigning explicit ordinal values to enum members is rejected:

type te = (a = 1, b = 5, c = 10);
begin writeln(ord(a), '|', ord(b), '|', ord(c)); end.
{ fpc: 1|5|10    pxx: error: unexpected token  (at '=') }

Plain enums ((a, b, c) → 0,1,2) and Ord on them already work.

Expected

Accept (name = constexpr, ...); members without a value continue from the previous (FPC semantics). Useful for mapping enums onto C/protocol numeric constants (ESP/IDF, wire formats).

Repro

tools/fpc_diff_probe.sh (enum-explicit).

Resolution (2026-06-23)

Parser (enum decl in ParseTypeSection): each member now accepts an optional = constexpr ordinal; a valueless member continues from the previous value + 1 (FPC semantics). (a=1, b=5, c, d=10) -> 1,5,6,10, byte-identical to FPC. Front-end only. Closes feature-enum-explicit-values.