Enum CronError

Source

pub enum CronError {
    ParseError(Error),
    DurationOutOfRange,
    Unknown,
}

Expand description

Re-export of the cron error type.

All fallible operations in this crate return a Result<T, CronError>. Errors that can occur when using CronTab.

This enum represents all possible errors that can occur during cron job scheduling operations.

§Examples

use cron_tab::{Cron, CronError};
use chrono::Utc;

let mut cron = Cron::new(Utc);

// This will result in a ParseError due to invalid cron expression
match cron.add_fn("invalid expression", || println!("Hello")) {
    Ok(job_id) => println!("Job added with ID: {}", job_id),
    Err(CronError::ParseError(e)) => println!("Invalid cron expression: {}", e),
    Err(CronError::DurationOutOfRange) => println!("Duration too large"),
    Err(CronError::Unknown) => println!("An unknown error occurred"),
}

Variants§

§

ParseError(Error)

Error that occurs when a cron expression cannot be parsed.

This is the most common error and occurs when an invalid cron expression is provided to add_fn or add_fn.

§Common Causes

Invalid field values (e.g., hour > 23, minute > 59)
Incorrect number of fields (should be 7: sec min hour day month weekday year)
Invalid special characters or syntax
Malformed range expressions

§Examples

use cron_tab::{Cron, CronError};
use chrono::Utc;

let mut cron = Cron::new(Utc);
 
// These will all result in ParseError:
 
// Too few fields
assert!(matches!(
    cron.add_fn("* * *", || {}),
    Err(CronError::ParseError(_))
));
 
// Invalid hour (25 > 23)
assert!(matches!(
    cron.add_fn("0 0 25 * * * *", || {}),
    Err(CronError::ParseError(_))
));
 
// Invalid syntax
assert!(matches!(
    cron.add_fn("not-a-cron-expression", || {}),
    Err(CronError::ParseError(_))
));

§

DurationOutOfRange

Error that occurs when a duration is out of range.

This error occurs when using add_fn_after or add_fn_after with a duration that exceeds the maximum supported value.

§Maximum Duration

The maximum supported duration is approximately 292 years (i64::MAX milliseconds).

§Examples

use cron_tab::{Cron, CronError};
use chrono::Utc;
use std::time::Duration;

let mut cron = Cron::new(Utc);

// This may result in DurationOutOfRange for extremely large durations
let very_long_time = Duration::from_secs(u64::MAX);
match cron.add_fn_after(very_long_time, || {}) {
    Ok(job_id) => println!("Job scheduled"),
    Err(CronError::DurationOutOfRange) => println!("Duration too large"),
    _ => {},
}

§

Unknown

A catch-all error for unexpected conditions.

This error type is reserved for future use and should rarely occur in normal operation. If you encounter this error, it may indicate a bug in the library or an unexpected system condition.