error Design

Responsibilities

• Provide the shared error vocabulary for checked linear-algebra APIs.
• Keep a stable machine-readable kind beside a human-readable message.
• Let callers branch on common failure categories without parsing text.
• Preserve arithmetic errors from lower-level scalar operations through ArithmeticFailure.

Non-Responsibilities

• Do not implement matrix, vector, or backend algorithms here.
• Do not define recovery policies for singular matrices, non-convergence, or arithmetic failures.
• Do not decide logging, localization, or presentation formatting.
• Do not use the text message as the semantic contract for control flow.

Maintenance Notes

Add a new error kind only when checked public APIs need to expose a distinct class of failure. Keep constructors and predicate methods aligned with the enum so callers can create and inspect errors without destructuring values directly.