qubit_dcl/double_checked/
callback_error.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025 - 2026 Haixing Hu.
4 *
5 *    SPDX-License-Identifier: Apache-2.0
6 *
7 *    Licensed under the Apache License, Version 2.0.
8 *
9 ******************************************************************************/
10//! # Callback Error
11//!
12//! Provides callback error information for double-checked execution.
13//!
14
15use std::fmt;
16
17/// Common error information for prepare lifecycle callbacks.
18///
19/// This keeps the error type name together with the message so callers can
20/// classify failures without depending on fragile string matching.
21///
22/// # Examples
23///
24/// ```rust
25/// use qubit_dcl::double_checked::CallbackError;
26///
27/// let prepare_error = CallbackError::with_type("prepare", "Resource is locked");
28/// assert_eq!(prepare_error.callback_type(), Some("prepare"));
29/// println!("prepare_error = {:?}", prepare_error);
30/// ```
31#[derive(Debug, Clone)]
32pub struct CallbackError {
33    /// Error message produced by the callback.
34    message: String,
35
36    /// Concrete type name, when available.
37    callback_type: Option<&'static str>,
38}
39
40impl CallbackError {
41    /// Builds a callback error without type metadata.
42    #[inline]
43    pub fn from_display<T: fmt::Display>(error: T) -> Self {
44        Self {
45            message: error.to_string(),
46            callback_type: None,
47        }
48    }
49
50    /// Builds a callback error with explicit callback type metadata.
51    #[inline]
52    pub fn with_type<T: fmt::Display>(source_type: &'static str, error: T) -> Self {
53        Self {
54            message: error.to_string(),
55            callback_type: Some(source_type),
56        }
57    }
58
59    /// Returns the raw message.
60    #[inline]
61    pub fn message(&self) -> &str {
62        &self.message
63    }
64
65    /// Returns the callback type label, when available.
66    #[inline]
67    pub fn callback_type(&self) -> Option<&'static str> {
68        self.callback_type
69    }
70
71    /// Returns whether the callback type label is set.
72    #[inline]
73    pub fn is_typed(&self) -> bool {
74        self.callback_type.is_some()
75    }
76}
77
78impl fmt::Display for CallbackError {
79    #[inline]
80    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
81        match self.callback_type {
82            Some(callback_type) => write!(f, "{}: {}", callback_type, self.message),
83            None => write!(f, "{}", self.message),
84        }
85    }
86}
qubit_dcl/double_checked/callback_error.rs

qubit_dcl/double_checked/
callback_error.rs
