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//! C-compatible error type.
/// Error code, indicating failure type.
///
/// Error messages are designating by an error code of less than 0.
/// This is to be compatible with C conventions.
///
/// # FFI
///
/// For interfacing with FFI-code, this may be approximated by:
/// ```text
/// const int32_t OVERFLOW = -1;
/// const int32_t UNDERFLOW = -2;
/// const int32_t INVALID_DIGIT = -3;
/// const int32_t EMPTY = -4;
/// const int32_t EMPTY_FRACTION = -5;
/// const int32_t EMPTY_EXPONENT = -6;
/// ```
///
/// # Safety
///
/// Assigning any value outside the range `[-3, 0]` to value of type
/// ErrorCode may invoke undefined-behavior.
#[repr(i32)]
#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
pub enum ErrorCode {
/// Integral overflow occurred during numeric parsing.
///
/// Numeric overflow takes precedence over the presence of an invalid
/// digit.
Overflow = -1,
/// Integral underflow occurred during numeric parsing.
///
/// Numeric overflow takes precedence over the presence of an invalid
/// digit.
Underflow = -2,
/// Invalid digit found before string termination.
InvalidDigit = -3,
/// Empty byte array found.
Empty = -4,
/// Empty fraction found.
EmptyFraction = -5,
/// Empty exponent found.
EmptyExponent = -6,
// We may add additional variants later, so ensure that client matching
// does not depend on exhaustive matching.
#[doc(hidden)]
__Nonexhaustive = -7,
}
/// C-compatible error for FFI.
#[repr(C)]
#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
pub struct Error {
/// Error code designating the type of error occurred.
pub code: ErrorCode,
/// Optional position within the buffer for the error.
pub index: usize,
}
impl From<ErrorCode> for Error {
#[inline]
fn from(code: ErrorCode) -> Self {
Error { code: code, index: 0 }
}
}
impl From<(ErrorCode, usize)> for Error {
#[inline]
fn from(error: (ErrorCode, usize)) -> Self {
Error { code: error.0, index: error.1 }
}
}
pub(crate) mod error_ffi {
pub use super::{Error, ErrorCode};
/// Check if the error code designates integer overflow.
#[no_mangle]
pub extern fn error_is_overflow(error: Error) -> bool {
error.code == ErrorCode::Overflow
}
/// Check if the error code designates integer underflow.
#[no_mangle]
pub extern fn error_is_underflow(error: Error) -> bool {
error.code == ErrorCode::Underflow
}
/// Check if the error code designates an invalid digit was encountered.
#[no_mangle]
pub extern fn error_is_invalid_digit(error: Error) -> bool {
error.code == ErrorCode::InvalidDigit
}
/// Check if the error code designates an empty byte array was encountered.
#[no_mangle]
pub extern fn error_is_empty(error: Error) -> bool {
error.code == ErrorCode::Empty
}
/// Check if the error code designates an empty fraction was encountered.
#[no_mangle]
pub extern fn error_is_empty_fraction(error: Error) -> bool {
error.code == ErrorCode::EmptyFraction
}
/// Check if the error code designates an empty exponent was encountered.
#[no_mangle]
pub extern fn error_is_empty_exponent(error: Error) -> bool {
error.code == ErrorCode::EmptyExponent
}
} // error_ffi