Module error 

The error model: the Rust replacement for Java varar-core’s typed exception hierarchy (CellMismatchException, ReturnShapeException, UnexpectedPassException, author AssertionError). Result/panic-catch replace throw; instanceof dispatch becomes match.

Structs

FailureLocation

Where a failure points in the .md — the structural replacement for Java’s synthetic StackTraceElement injection. line is the anchor’s start line (all a rendered stack frame can show); anchor is its full offset range, so a renderer can underline the failing step instead of its whole line.

HandlerError

A handler-signalled failure (author Err(...) or a caught panic) — the analog of an arbitrary thrown RuntimeException/AssertionError.

StepFailure

A caught step failure plus its (optional) source location.

Enums

RegistryError

A registration-time (author-wiring) error — never a step failure.

StepError

A step failure verdict — the closed union replacing the exception hierarchy.