dec 0.4.6

// Copyright Materialize, Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License in the LICENSE file at the
// root of this repository, or online at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::error::Error;
use std::fmt;

/// An error indicating that a string is not a valid decimal number.
#[derive(Debug, Eq, PartialEq)]
pub struct ParseDecimalError;

impl fmt::Display for ParseDecimalError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("invalid decimal syntax")
    }
}

impl Error for ParseDecimalError {}

/// An error indicating that a precision is not valid for a given context.
#[derive(Debug, Eq, PartialEq)]
pub struct InvalidPrecisionError;

impl fmt::Display for InvalidPrecisionError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("invalid decimal precision")
    }
}

impl Error for InvalidPrecisionError {}

/// An error indicating that a minimum exponent or maximum exponent is not valid
/// for a given context.
#[derive(Debug, Eq, PartialEq)]
pub struct InvalidExponentError;

impl fmt::Display for InvalidExponentError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("invalid decimal exponent")
    }
}

impl Error for InvalidExponentError {}

/// An error indicating that a value cannot be cast to a primitive type.
///
/// Causes for this failure include calling cast functions on values:
/// - Representing infinity or NaN
/// - With non-zero exponent values
/// - Whose coefficient doesn't fit into the target, e.g. values that require
///   too many digits of precision.
#[derive(Debug, Eq, PartialEq)]
pub struct TryFromDecimalError;

impl fmt::Display for TryFromDecimalError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("decimal cannot be expressed in target primitive type")
    }
}

impl Error for TryFromDecimalError {}

/// An error indicating a value cannot be precisely cast to a Decimal value, e.g.
/// the cast requires truncating significant digits.
#[derive(Debug, Eq, PartialEq)]
pub struct TryIntoDecimalError;

impl fmt::Display for TryIntoDecimalError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("value cannot be precisely expressed as decimal")
    }
}

impl Error for TryIntoDecimalError {}

/// An error indicating that a value's coefficient cannot be cast to a primitive
/// type.
#[derive(Debug, Eq, PartialEq)]
pub struct InvalidCoefficientError;

impl fmt::Display for InvalidCoefficientError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("decimal's coefficient cannot be expressed in target primitive type")
    }
}

impl Error for InvalidCoefficientError {}

/// An error indicating that a value's coefficient cannot be cast to a primitive
/// type.
#[derive(Debug, Eq, PartialEq)]
pub struct FromBcdError;

impl fmt::Display for FromBcdError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("bcd or scale value invalid, either corrupted or out of acceptable range")
    }
}

impl Error for FromBcdError {}