Enum Error 

pub enum Error {
    Signature(String),
    Field(String),
    Module(String),
    Prediction(String),
    Serialization(String),
    AssertionFailed {
        field: Sym,
        description: &'static str,
    },
    InvalidPattern(String),
    Io(Error),
    Json(Error),
    Utf8(Utf8Error),
    Storage(String),
    Memory {
        operation: &'static str,
        reason: String,
        suggestion: &'static str,
    },
    Parse(String),
    Validation(String),
    Optimization(OptimizationDetails),
    Other(String),
}

Main error type for Kkachi library

Variants

Signature(String)

Signature-related errors

Field(String)

Field-related errors

Module(String)

Module execution errors

Prediction(String)

Prediction errors

Serialization(String)

Serialization errors

AssertionFailed

Assertion failure

Fields

field: Sym

The field that failed assertion

description: &'static str

Description of the assertion

InvalidPattern(String)

Invalid pattern (regex)

Io(Error)

I/O errors (only with std feature)

Json(Error)

JSON errors

Utf8(Utf8Error)

UTF-8 encoding errors

Storage(String)

Storage errors (DuckDB, etc.)

Memory

Memory store errors with actionable context.

Fields

operation: &'static str

What operation failed.

reason: String

Why it failed.

suggestion: &'static str

What to do about it.

Parse(String)

Parse errors (for template parsing, etc.)

Validation(String)

Validation errors (for format validation, etc.)

Optimization(OptimizationDetails)

Optimization failure - prompt did not converge.

This is DISTINCT from library errors. Optimization errors are expected outcomes that can inform the optimization process. Use Error::is_optimization_error() to check, and Error::optimization_details() to extract context.

Other(String)

Generic error

Implementations

impl Error

pub fn storage(msg: impl Into<String>) -> Self

Create a storage error.

pub fn memory( operation: &'static str, reason: impl Into<String>, suggestion: &'static str, ) -> Self

Create a memory error with operation context, reason, and suggestion.

pub fn signature(msg: impl Into<String>) -> Self

Create a signature error

pub fn field(msg: impl Into<String>) -> Self

Create a field error

pub fn module(msg: impl Into<String>) -> Self

Create a module error

pub fn prediction(msg: impl Into<String>) -> Self

Create a prediction error

pub fn parse(msg: impl Into<String>) -> Self

Create a parse error

pub fn validation(msg: impl Into<String>) -> Self

Create a validation error

pub fn io(msg: impl Into<String>) -> Self

Create an I/O error with a custom message

pub fn optimization(score: f64, iterations: u32, threshold: f64) -> Self

Create an optimization error (prompt did not converge).

Use this when optimization fails to meet the threshold, not for library/infrastructure errors.

pub fn optimization_with_feedback( score: f64, iterations: u32, threshold: f64, feedback: impl Into<String>, ) -> Self

Create an optimization error with feedback.

pub fn is_optimization_error(&self) -> bool

Check if this is an optimization error (prompt didn’t converge).

Optimization errors are expected and should inform the optimization process. They are distinct from library errors which indicate bugs or infrastructure issues.

Example

match result {
    Ok(output) => handle_success(output),
    Err(e) if e.is_optimization_error() => {
        // Use the feedback to improve the prompt
        let details = e.optimization_details().unwrap();
        improve_prompt(details.feedback.as_deref());
    }
    Err(e) => {
        // This is a library bug - report it
        panic!("Library error: {}", e);
    }
}

pub fn is_library_error(&self) -> bool

Check if this is a library/infrastructure error (not optimization).

Library errors indicate bugs or configuration issues in kkachi itself, not failures in the optimization process.

pub fn optimization_details(&self) -> Option<&OptimizationDetails>

Get optimization details if this is an optimization error.

Returns None for library errors.

pub fn optimization_details_mut(&mut self) -> Option<&mut OptimizationDetails>

Get mutable optimization details if this is an optimization error.

pub fn is_recoverable(&self) -> bool

Check if this error can be recovered from (optimization errors can).

pub fn category(&self) -> &'static str

Get the error category for logging/metrics.

Trait Implementations

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Error

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Utf8Error> for Error

fn from(source: Utf8Error) -> Self

Converts to this type from the input type.