PuduLangLog.Domain.EventId

type: module path: "@root/src/PuduLangLog/Domain/EventId.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.5 depth_status: MEDIUM tags: [module, leaf, pure] aliases: [PuduLangLog.Domain.EventId]

Purpose

Gives every message template a stable 32-bit identifier, so all events written from one template can be found together however their values differ. The rendered compact JSON formatter writes it as @i, and expressions read it as @i.

Interface

Signatures

export fn compute(template: Str) -> UInt32

export fn hex(id: UInt32) -> Str

Linkage

• Requires: Std.Option, Std.Text.
• Consumed by: [[src/PuduLangLog/Formatting/Compact]] and the expression evaluator.

Algorithm

1. For each character: add its code point, add the hash shifted left by 10, and xor the hash shifted right by 6, all in wrapping 32-bit arithmetic.
2. Finish by adding the hash shifted left by 3, xoring it shifted right by 11, and adding it shifted left by 15.
3. hex writes eight lower-case hexadecimal digits.

Negative Logic (Prohibited Paths)

• The hash depends on the template text only, never on values or time.

Edge Cases

• The empty template hashes to 00000000.

Depth

DEPTH 0.5 (MEDIUM). Tested by test/PuduLangLog/Domain/OutputTest.

Grill Log

• Q: Why this hash? A: It is short, has no table, and gives the same value on every platform, which is what an identifier stored in log files needs. _Rejected:_ a cryptographic hash (longer than useful).

Referenced by

[[domain/Template]] · [[src/PuduLangLog/_MOC]] · [[src/PuduLangLog/Expressions/Evaluator]] · [[src/PuduLangLog/Formatting/Compact]]