mongol_convert/
error.rs

1//! Error type. Folds the Java `State` / `TranslateState` / `DelehiState` runtime codes into one
2//! Rust enum.
3//!
4//! Note (design decision #3): a content-level *unmappable code point* is **not** an error here —
5//! it is passed through unchanged. So [`MongolConvertError::NotFoundInMapper`] is reserved for internal/
6//! diagnostic use. The default build's public `translate` returns `Err` only for structural problems
7//! (unsupported encoding, unsupported series, unknown enum string) and for UTN #57 conversion
8//! failures reported by the in-process `zvvnmod-utn57` backend.
9
10use crate::code_type::CodeType;
11use std::fmt;
12
13#[derive(Debug, Clone, PartialEq, Eq)]
14pub enum MongolConvertError {
15    /// No translate rule registered for this code (defensive; should be unreachable for supported types).
16    MissTranslateRule(CodeType),
17    /// Internal stack underflow during fragment processing.
18    NothingToPop,
19    /// A key was not found in a mapper table (internal/diagnostic; content path passes through instead).
20    NotFoundInMapper(String),
21    /// A code's series was neither Letter nor Shape (defensive; unreachable given the enum).
22    NotSupportedCodeSeries(CodeType),
23    /// A string could not be parsed into a [`CodeType`].
24    UnsupportedEnumType(String),
25    /// Conversion involving this code is not supported in the active build.
26    Unsupported(CodeType),
27    /// Suffix separator repair currently accepts MenkLetter and Delehi source text only.
28    UnsupportedInputRepair(CodeType),
29    /// An in-process UTN #57 conversion (`zvvnmod-utn57` + `mongol-norm`), either direction, failed.
30    Utn57(String),
31}
32
33impl fmt::Display for MongolConvertError {
34    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
35        match self {
36            MongolConvertError::MissTranslateRule(ct) => write!(f, "missing translate rule for {ct:?}"),
37            MongolConvertError::NothingToPop => write!(f, "nothing to pop"),
38            MongolConvertError::NotFoundInMapper(k) => write!(f, "key not found in mapper: {k:?}"),
39            MongolConvertError::NotSupportedCodeSeries(ct) => {
40                write!(f, "unsupported code series for {ct:?}")
41            }
42            MongolConvertError::UnsupportedEnumType(s) => write!(f, "unsupported encoding name: {s:?}"),
43            MongolConvertError::Unsupported(ct) => write!(f, "conversion not supported for {ct:?}"),
44            MongolConvertError::UnsupportedInputRepair(ct) => write!(
45                f,
46                "suffix separator repair requires menk_letter or delehi input, got {ct:?}"
47            ),
48            MongolConvertError::Utn57(reason) => write!(f, "UTN #57 conversion failed: {reason}"),
49        }
50    }
51}
52
53impl std::error::Error for MongolConvertError {}
mongol_convert/error.rs

mongol_convert/
error.rs
