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Diffstat (limited to 'src/parser/errors.rs')
| -rw-r--r-- | src/parser/errors.rs | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/parser/errors.rs b/src/parser/errors.rs new file mode 100644 index 0000000..859ed53 --- /dev/null +++ b/src/parser/errors.rs @@ -0,0 +1,316 @@ +use std::error::Error as StdError; +use std::fmt::{Display, Formatter, Result}; + +use crate::parser::prelude::*; +use crate::Key; + +use winnow::error::ContextError; +use winnow::error::ParseError; + +/// Type representing a TOML parse error +#[derive(Debug, Clone, Eq, PartialEq, Hash)] +pub struct TomlError { + message: String, + original: Option<String>, + keys: Vec<String>, + span: Option<std::ops::Range<usize>>, +} + +impl TomlError { + pub(crate) fn new(error: ParseError<Input<'_>, ContextError>, mut original: Input<'_>) -> Self { + use winnow::stream::Stream; + + let offset = error.offset(); + let span = if offset == original.len() { + offset..offset + } else { + offset..(offset + 1) + }; + + let message = error.inner().to_string(); + let original = original.finish(); + + Self { + message, + original: Some( + String::from_utf8(original.to_owned()).expect("original document was utf8"), + ), + keys: Vec::new(), + span: Some(span), + } + } + + #[cfg(feature = "serde")] + pub(crate) fn custom(message: String, span: Option<std::ops::Range<usize>>) -> Self { + Self { + message, + original: None, + keys: Vec::new(), + span, + } + } + + #[cfg(feature = "serde")] + pub(crate) fn add_key(&mut self, key: String) { + self.keys.insert(0, key); + } + + /// What went wrong + pub fn message(&self) -> &str { + &self.message + } + + /// The start/end index into the original document where the error occurred + pub fn span(&self) -> Option<std::ops::Range<usize>> { + self.span.clone() + } + + #[cfg(feature = "serde")] + pub(crate) fn set_span(&mut self, span: Option<std::ops::Range<usize>>) { + self.span = span; + } + + #[cfg(feature = "serde")] + pub(crate) fn set_original(&mut self, original: Option<String>) { + self.original = original; + } +} + +/// Displays a TOML parse error +/// +/// # Example +/// +/// TOML parse error at line 1, column 10 +/// | +/// 1 | 00:32:00.a999999 +/// | ^ +/// Unexpected `a` +/// Expected `digit` +/// While parsing a Time +/// While parsing a Date-Time +impl Display for TomlError { + fn fmt(&self, f: &mut Formatter<'_>) -> Result { + let mut context = false; + if let (Some(original), Some(span)) = (&self.original, self.span()) { + context = true; + + let (line, column) = translate_position(original.as_bytes(), span.start); + let line_num = line + 1; + let col_num = column + 1; + let gutter = line_num.to_string().len(); + let content = original.split('\n').nth(line).expect("valid line number"); + + writeln!( + f, + "TOML parse error at line {}, column {}", + line_num, col_num + )?; + // | + for _ in 0..=gutter { + write!(f, " ")?; + } + writeln!(f, "|")?; + + // 1 | 00:32:00.a999999 + write!(f, "{} | ", line_num)?; + writeln!(f, "{}", content)?; + + // | ^ + for _ in 0..=gutter { + write!(f, " ")?; + } + write!(f, "|")?; + for _ in 0..=column { + write!(f, " ")?; + } + // The span will be empty at eof, so we need to make sure we always print at least + // one `^` + write!(f, "^")?; + for _ in (span.start + 1)..(span.end.min(span.start + content.len())) { + write!(f, "^")?; + } + writeln!(f)?; + } + writeln!(f, "{}", self.message)?; + if !context && !self.keys.is_empty() { + writeln!(f, "in `{}`", self.keys.join("."))?; + } + + Ok(()) + } +} + +impl StdError for TomlError { + fn description(&self) -> &'static str { + "TOML parse error" + } +} + +fn translate_position(input: &[u8], index: usize) -> (usize, usize) { + if input.is_empty() { + return (0, index); + } + + let safe_index = index.min(input.len() - 1); + let column_offset = index - safe_index; + let index = safe_index; + + let nl = input[0..index] + .iter() + .rev() + .enumerate() + .find(|(_, b)| **b == b'\n') + .map(|(nl, _)| index - nl - 1); + let line_start = match nl { + Some(nl) => nl + 1, + None => 0, + }; + let line = input[0..line_start].iter().filter(|b| **b == b'\n').count(); + let line = line; + + let column = std::str::from_utf8(&input[line_start..=index]) + .map(|s| s.chars().count() - 1) + .unwrap_or_else(|_| index - line_start); + let column = column + column_offset; + + (line, column) +} + +#[cfg(test)] +mod test_translate_position { + use super::*; + + #[test] + fn empty() { + let input = b""; + let index = 0; + let position = translate_position(&input[..], index); + assert_eq!(position, (0, 0)); + } + + #[test] + fn start() { + let input = b"Hello"; + let index = 0; + let position = translate_position(&input[..], index); + assert_eq!(position, (0, 0)); + } + + #[test] + fn end() { + let input = b"Hello"; + let index = input.len() - 1; + let position = translate_position(&input[..], index); + assert_eq!(position, (0, input.len() - 1)); + } + + #[test] + fn after() { + let input = b"Hello"; + let index = input.len(); + let position = translate_position(&input[..], index); + assert_eq!(position, (0, input.len())); + } + + #[test] + fn first_line() { + let input = b"Hello\nWorld\n"; + let index = 2; + let position = translate_position(&input[..], index); + assert_eq!(position, (0, 2)); + } + + #[test] + fn end_of_line() { + let input = b"Hello\nWorld\n"; + let index = 5; + let position = translate_position(&input[..], index); + assert_eq!(position, (0, 5)); + } + + #[test] + fn start_of_second_line() { + let input = b"Hello\nWorld\n"; + let index = 6; + let position = translate_position(&input[..], index); + assert_eq!(position, (1, 0)); + } + + #[test] + fn second_line() { + let input = b"Hello\nWorld\n"; + let index = 8; + let position = translate_position(&input[..], index); + assert_eq!(position, (1, 2)); + } +} + +#[derive(Debug, Clone)] +pub(crate) enum CustomError { + DuplicateKey { + key: String, + table: Option<Vec<Key>>, + }, + DottedKeyExtendWrongType { + key: Vec<Key>, + actual: &'static str, + }, + OutOfRange, + #[cfg_attr(feature = "unbounded", allow(dead_code))] + RecursionLimitExceeded, +} + +impl CustomError { + pub(crate) fn duplicate_key(path: &[Key], i: usize) -> Self { + assert!(i < path.len()); + let key = &path[i]; + let repr = key.display_repr(); + Self::DuplicateKey { + key: repr.into(), + table: Some(path[..i].to_vec()), + } + } + + pub(crate) fn extend_wrong_type(path: &[Key], i: usize, actual: &'static str) -> Self { + assert!(i < path.len()); + Self::DottedKeyExtendWrongType { + key: path[..=i].to_vec(), + actual, + } + } +} + +impl StdError for CustomError { + fn description(&self) -> &'static str { + "TOML parse error" + } +} + +impl Display for CustomError { + fn fmt(&self, f: &mut Formatter<'_>) -> Result { + match self { + CustomError::DuplicateKey { key, table } => { + if let Some(table) = table { + if table.is_empty() { + write!(f, "duplicate key `{}` in document root", key) + } else { + let path = table.iter().map(|k| k.get()).collect::<Vec<_>>().join("."); + write!(f, "duplicate key `{}` in table `{}`", key, path) + } + } else { + write!(f, "duplicate key `{}`", key) + } + } + CustomError::DottedKeyExtendWrongType { key, actual } => { + let path = key.iter().map(|k| k.get()).collect::<Vec<_>>().join("."); + write!( + f, + "dotted key `{}` attempted to extend non-table type ({})", + path, actual + ) + } + CustomError::OutOfRange => write!(f, "value is out of range"), + CustomError::RecursionLimitExceeded => write!(f, "recursion limit exceded"), + } + } +} |