Module error 

Error handling for lib3mf-core.

This module defines the error types returned by all fallible operations in the library.

Design Philosophy

The library follows a strict no-panic policy:

• All errors are returned as Result<T, Lib3mfError>, never panicked
• Invalid user input (malformed 3MF files, bad parameters) produces errors, not panics
• Internal consistency violations are also returned as errors (via InvalidStructure)

This makes the library safe to use in production environments where panics are unacceptable.

Error Types

Lib3mfError is the main error enum, with variants covering different failure modes:

• Io: File system errors, network errors, ZIP reading failures
• Validation: Model failed validation checks (see crate::validation)
• ResourceNotFound: Referenced resource ID doesn’t exist in the model
• InvalidStructure: Malformed XML, missing required elements, spec violations
• EncryptionError: Cryptographic operations failed (wrong key, tampered data)
• FeatureNotEnabled: Operation requires a cargo feature that wasn’t enabled

Usage

The Result type alias is provided for convenience:

use lib3mf_core::error::{Lib3mfError, Result};

fn parse_something() -> Result<String> {
    // Use the ? operator to propagate errors
    Ok("success".to_string())
}

Error Context

Most error variants include a String message with context about what failed:

use lib3mf_core::error::Lib3mfError;

let error = Lib3mfError::InvalidStructure(
    "Missing required 'unit' attribute on <model> element".to_string()
);

// Error messages are human-readable
assert_eq!(
    error.to_string(),
    "Invalid 3MF structure: Missing required 'unit' attribute on <model> element"
);

Enums

Lib3mfError

Type Aliases

Result