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Diffstat (limited to 'vendor/pest/src/error.rs')
| -rw-r--r-- | vendor/pest/src/error.rs | 807 |
1 files changed, 807 insertions, 0 deletions
diff --git a/vendor/pest/src/error.rs b/vendor/pest/src/error.rs new file mode 100644 index 000000000..d6b76a82a --- /dev/null +++ b/vendor/pest/src/error.rs @@ -0,0 +1,807 @@ +// pest. The Elegant Parser +// Copyright (c) 2018 Dragoș Tiselice +// +// Licensed under the Apache License, Version 2.0 +// <LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0> or the MIT +// license <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. All files in the project carrying such notice may not be copied, +// modified, or distributed except according to those terms. + +//! Types for different kinds of parsing failures. + +use std::cmp; +use std::error; +use std::fmt; +use std::mem; + +use position::Position; +use span::Span; +use RuleType; + +/// Parse-related error type. +#[derive(Clone, Debug, Eq, Hash, PartialEq)] +pub struct Error<R> { + /// Variant of the error + pub variant: ErrorVariant<R>, + /// Location within the input string + pub location: InputLocation, + /// Line/column within the input string + pub line_col: LineColLocation, + path: Option<String>, + line: String, + continued_line: Option<String>, +} + +/// Different kinds of parsing errors. +#[derive(Clone, Debug, Eq, Hash, PartialEq)] +pub enum ErrorVariant<R> { + /// Generated parsing error with expected and unexpected `Rule`s + ParsingError { + /// Positive attempts + positives: Vec<R>, + /// Negative attempts + negatives: Vec<R>, + }, + /// Custom error with a message + CustomError { + /// Short explanation + message: String, + }, +} + +/// Where an `Error` has occurred. +#[derive(Clone, Debug, Eq, Hash, PartialEq)] +pub enum InputLocation { + /// `Error` was created by `Error::new_from_pos` + Pos(usize), + /// `Error` was created by `Error::new_from_span` + Span((usize, usize)), +} + +/// Line/column where an `Error` has occurred. +#[derive(Clone, Debug, Eq, Hash, PartialEq)] +pub enum LineColLocation { + /// Line/column pair if `Error` was created by `Error::new_from_pos` + Pos((usize, usize)), + /// Line/column pairs if `Error` was created by `Error::new_from_span` + Span((usize, usize), (usize, usize)), +} + +impl<R: RuleType> Error<R> { + /// Creates `Error` from `ErrorVariant` and `Position`. + /// + /// # Examples + /// + /// ``` + /// # use pest::error::{Error, ErrorVariant}; + /// # use pest::Position; + /// # #[allow(non_camel_case_types)] + /// # #[allow(dead_code)] + /// # #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] + /// # enum Rule { + /// # open_paren, + /// # closed_paren + /// # } + /// # let input = ""; + /// # let pos = Position::from_start(input); + /// let error = Error::new_from_pos( + /// ErrorVariant::ParsingError { + /// positives: vec![Rule::open_paren], + /// negatives: vec![Rule::closed_paren] + /// }, + /// pos + /// ); + /// + /// println!("{}", error); + /// ``` + #[allow(clippy::needless_pass_by_value)] + pub fn new_from_pos(variant: ErrorVariant<R>, pos: Position) -> Error<R> { + Error { + variant, + location: InputLocation::Pos(pos.pos()), + path: None, + line: visualize_whitespace(pos.line_of()), + continued_line: None, + line_col: LineColLocation::Pos(pos.line_col()), + } + } + + /// Creates `Error` from `ErrorVariant` and `Span`. + /// + /// # Examples + /// + /// ``` + /// # use pest::error::{Error, ErrorVariant}; + /// # use pest::{Position, Span}; + /// # #[allow(non_camel_case_types)] + /// # #[allow(dead_code)] + /// # #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] + /// # enum Rule { + /// # open_paren, + /// # closed_paren + /// # } + /// # let input = ""; + /// # let start = Position::from_start(input); + /// # let end = start.clone(); + /// # let span = start.span(&end); + /// let error = Error::new_from_span( + /// ErrorVariant::ParsingError { + /// positives: vec![Rule::open_paren], + /// negatives: vec![Rule::closed_paren] + /// }, + /// span + /// ); + /// + /// println!("{}", error); + /// ``` + #[allow(clippy::needless_pass_by_value)] + pub fn new_from_span(variant: ErrorVariant<R>, span: Span) -> Error<R> { + let end = span.end_pos(); + + let mut end_line_col = end.line_col(); + // end position is after a \n, so we want to point to the visual lf symbol + if end_line_col.1 == 1 { + let mut visual_end = end.clone(); + visual_end.skip_back(1); + let lc = visual_end.line_col(); + end_line_col = (lc.0, lc.1 + 1); + }; + + let mut line_iter = span.lines(); + let start_line = visualize_whitespace(line_iter.next().unwrap_or("")); + let continued_line = line_iter.last().map(visualize_whitespace); + + Error { + variant, + location: InputLocation::Span((span.start(), end.pos())), + path: None, + line: start_line, + continued_line, + line_col: LineColLocation::Span(span.start_pos().line_col(), end_line_col), + } + } + + /// Returns `Error` variant with `path` which is shown when formatted with `Display`. + /// + /// # Examples + /// + /// ``` + /// # use pest::error::{Error, ErrorVariant}; + /// # use pest::Position; + /// # #[allow(non_camel_case_types)] + /// # #[allow(dead_code)] + /// # #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] + /// # enum Rule { + /// # open_paren, + /// # closed_paren + /// # } + /// # let input = ""; + /// # let pos = Position::from_start(input); + /// Error::new_from_pos( + /// ErrorVariant::ParsingError { + /// positives: vec![Rule::open_paren], + /// negatives: vec![Rule::closed_paren] + /// }, + /// pos + /// ).with_path("file.rs"); + /// ``` + pub fn with_path(mut self, path: &str) -> Error<R> { + self.path = Some(path.to_owned()); + + self + } + + /// Renames all `Rule`s if this is a [`ParsingError`]. It does nothing when called on a + /// [`CustomError`]. + /// + /// Useful in order to rename verbose rules or have detailed per-`Rule` formatting. + /// + /// [`ParsingError`]: enum.ErrorVariant.html#variant.ParsingError + /// [`CustomError`]: enum.ErrorVariant.html#variant.CustomError + /// + /// # Examples + /// + /// ``` + /// # use pest::error::{Error, ErrorVariant}; + /// # use pest::Position; + /// # #[allow(non_camel_case_types)] + /// # #[allow(dead_code)] + /// # #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] + /// # enum Rule { + /// # open_paren, + /// # closed_paren + /// # } + /// # let input = ""; + /// # let pos = Position::from_start(input); + /// Error::new_from_pos( + /// ErrorVariant::ParsingError { + /// positives: vec![Rule::open_paren], + /// negatives: vec![Rule::closed_paren] + /// }, + /// pos + /// ).renamed_rules(|rule| { + /// match *rule { + /// Rule::open_paren => "(".to_owned(), + /// Rule::closed_paren => "closed paren".to_owned() + /// } + /// }); + /// ``` + pub fn renamed_rules<F>(mut self, f: F) -> Error<R> + where + F: FnMut(&R) -> String, + { + let variant = match self.variant { + ErrorVariant::ParsingError { + positives, + negatives, + } => { + let message = Error::parsing_error_message(&positives, &negatives, f); + ErrorVariant::CustomError { message } + } + variant => variant, + }; + + self.variant = variant; + + self + } + + fn start(&self) -> (usize, usize) { + match self.line_col { + LineColLocation::Pos(line_col) => line_col, + LineColLocation::Span(start_line_col, _) => start_line_col, + } + } + + fn spacing(&self) -> String { + let line = match self.line_col { + LineColLocation::Pos((line, _)) => line, + LineColLocation::Span((start_line, _), (end_line, _)) => cmp::max(start_line, end_line), + }; + + let line_str_len = format!("{}", line).len(); + + let mut spacing = String::new(); + for _ in 0..line_str_len { + spacing.push(' '); + } + + spacing + } + + fn underline(&self) -> String { + let mut underline = String::new(); + + let mut start = self.start().1; + let end = match self.line_col { + LineColLocation::Span(_, (_, mut end)) => { + let inverted_cols = start > end; + if inverted_cols { + mem::swap(&mut start, &mut end); + start -= 1; + end += 1; + } + + Some(end) + } + _ => None, + }; + let offset = start - 1; + let line_chars = self.line.chars(); + + for c in line_chars.take(offset) { + match c { + '\t' => underline.push('\t'), + _ => underline.push(' '), + } + } + + if let Some(end) = end { + if end - start > 1 { + underline.push('^'); + for _ in 2..(end - start) { + underline.push('-'); + } + underline.push('^'); + } else { + underline.push('^'); + } + } else { + underline.push_str("^---") + } + + underline + } + + fn message(&self) -> String { + match self.variant { + ErrorVariant::ParsingError { + ref positives, + ref negatives, + } => Error::parsing_error_message(positives, negatives, |r| format!("{:?}", r)), + ErrorVariant::CustomError { ref message } => message.clone(), + } + } + + fn parsing_error_message<F>(positives: &[R], negatives: &[R], mut f: F) -> String + where + F: FnMut(&R) -> String, + { + match (negatives.is_empty(), positives.is_empty()) { + (false, false) => format!( + "unexpected {}; expected {}", + Error::enumerate(negatives, &mut f), + Error::enumerate(positives, &mut f) + ), + (false, true) => format!("unexpected {}", Error::enumerate(negatives, &mut f)), + (true, false) => format!("expected {}", Error::enumerate(positives, &mut f)), + (true, true) => "unknown parsing error".to_owned(), + } + } + + fn enumerate<F>(rules: &[R], f: &mut F) -> String + where + F: FnMut(&R) -> String, + { + match rules.len() { + 1 => f(&rules[0]), + 2 => format!("{} or {}", f(&rules[0]), f(&rules[1])), + l => { + let separated = rules + .iter() + .take(l - 1) + .map(|r| f(r)) + .collect::<Vec<_>>() + .join(", "); + format!("{}, or {}", separated, f(&rules[l - 1])) + } + } + } + + pub(crate) fn format(&self) -> String { + let spacing = self.spacing(); + let path = self + .path + .as_ref() + .map(|path| format!("{}:", path)) + .unwrap_or_default(); + + let pair = (self.line_col.clone(), &self.continued_line); + if let (LineColLocation::Span(_, end), &Some(ref continued_line)) = pair { + let has_line_gap = end.0 - self.start().0 > 1; + if has_line_gap { + format!( + "{s }--> {p}{ls}:{c}\n\ + {s } |\n\ + {ls:w$} | {line}\n\ + {s } | ...\n\ + {le:w$} | {continued_line}\n\ + {s } | {underline}\n\ + {s } |\n\ + {s } = {message}", + s = spacing, + w = spacing.len(), + p = path, + ls = self.start().0, + le = end.0, + c = self.start().1, + line = self.line, + continued_line = continued_line, + underline = self.underline(), + message = self.message() + ) + } else { + format!( + "{s }--> {p}{ls}:{c}\n\ + {s } |\n\ + {ls:w$} | {line}\n\ + {le:w$} | {continued_line}\n\ + {s } | {underline}\n\ + {s } |\n\ + {s } = {message}", + s = spacing, + w = spacing.len(), + p = path, + ls = self.start().0, + le = end.0, + c = self.start().1, + line = self.line, + continued_line = continued_line, + underline = self.underline(), + message = self.message() + ) + } + } else { + format!( + "{s}--> {p}{l}:{c}\n\ + {s} |\n\ + {l} | {line}\n\ + {s} | {underline}\n\ + {s} |\n\ + {s} = {message}", + s = spacing, + p = path, + l = self.start().0, + c = self.start().1, + line = self.line, + underline = self.underline(), + message = self.message() + ) + } + } +} + +impl<R: RuleType> fmt::Display for Error<R> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "{}", self.format()) + } +} + +impl<'i, R: RuleType> error::Error for Error<R> { + fn description(&self) -> &str { + match self.variant { + ErrorVariant::ParsingError { .. } => "parsing error", + ErrorVariant::CustomError { ref message } => message, + } + } +} + +fn visualize_whitespace(input: &str) -> String { + input.to_owned().replace('\r', "␍").replace('\n', "␊") +} + +#[cfg(test)] +mod tests { + use super::super::position; + use super::*; + + #[test] + fn display_parsing_error_mixed() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![1, 2, 3], + negatives: vec![4, 5, 6], + }, + pos, + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = unexpected 4, 5, or 6; expected 1, 2, or 3", + ] + .join("\n") + ); + } + + #[test] + fn display_parsing_error_positives() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![1, 2], + negatives: vec![], + }, + pos, + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = expected 1 or 2", + ] + .join("\n") + ); + } + + #[test] + fn display_parsing_error_negatives() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![], + negatives: vec![4, 5, 6], + }, + pos, + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = unexpected 4, 5, or 6", + ] + .join("\n") + ); + } + + #[test] + fn display_parsing_error_unknown() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![], + negatives: vec![], + }, + pos, + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = unknown parsing error", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_pos() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::CustomError { + message: "error: big one".to_owned(), + }, + pos, + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = error: big one", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_span_two_lines() { + let input = "ab\ncd\nefgh"; + let start = position::Position::new(input, 4).unwrap(); + let end = position::Position::new(input, 9).unwrap(); + let error: Error<u32> = Error::new_from_span( + ErrorVariant::CustomError { + message: "error: big one".to_owned(), + }, + start.span(&end), + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + "3 | efgh", + " | ^^", + " |", + " = error: big one", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_span_three_lines() { + let input = "ab\ncd\nefgh"; + let start = position::Position::new(input, 1).unwrap(); + let end = position::Position::new(input, 9).unwrap(); + let error: Error<u32> = Error::new_from_span( + ErrorVariant::CustomError { + message: "error: big one".to_owned(), + }, + start.span(&end), + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 1:2", + " |", + "1 | ab␊", + " | ...", + "3 | efgh", + " | ^^", + " |", + " = error: big one", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_span_two_lines_inverted_cols() { + let input = "abcdef\ngh"; + let start = position::Position::new(input, 5).unwrap(); + let end = position::Position::new(input, 8).unwrap(); + let error: Error<u32> = Error::new_from_span( + ErrorVariant::CustomError { + message: "error: big one".to_owned(), + }, + start.span(&end), + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 1:6", + " |", + "1 | abcdef␊", + "2 | gh", + " | ^----^", + " |", + " = error: big one", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_span_end_after_newline() { + let input = "abcdef\n"; + let start = position::Position::new(input, 0).unwrap(); + let end = position::Position::new(input, 7).unwrap(); + assert!(start.at_start()); + assert!(end.at_end()); + + let error: Error<u32> = Error::new_from_span( + ErrorVariant::CustomError { + message: "error: big one".to_owned(), + }, + start.span(&end), + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 1:1", + " |", + "1 | abcdef␊", + " | ^-----^", + " |", + " = error: big one", + ] + .join("\n") + ); + } + + #[test] + fn display_custom_span_empty() { + let input = ""; + let start = position::Position::new(input, 0).unwrap(); + let end = position::Position::new(input, 0).unwrap(); + assert!(start.at_start()); + assert!(end.at_end()); + + let error: Error<u32> = Error::new_from_span( + ErrorVariant::CustomError { + message: "error: empty".to_owned(), + }, + start.span(&end), + ); + + assert_eq!( + format!("{}", error), + vec![ + " --> 1:1", + " |", + "1 | ", + " | ^", + " |", + " = error: empty", + ] + .join("\n") + ); + } + + #[test] + fn mapped_parsing_error() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![1, 2, 3], + negatives: vec![4, 5, 6], + }, + pos, + ) + .renamed_rules(|n| format!("{}", n + 1)); + + assert_eq!( + format!("{}", error), + vec![ + " --> 2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = unexpected 5, 6, or 7; expected 2, 3, or 4", + ] + .join("\n") + ); + } + + #[test] + fn error_with_path() { + let input = "ab\ncd\nef"; + let pos = position::Position::new(input, 4).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![1, 2, 3], + negatives: vec![4, 5, 6], + }, + pos, + ) + .with_path("file.rs"); + + assert_eq!( + format!("{}", error), + vec![ + " --> file.rs:2:2", + " |", + "2 | cd␊", + " | ^---", + " |", + " = unexpected 4, 5, or 6; expected 1, 2, or 3", + ] + .join("\n") + ); + } + + #[test] + fn underline_with_tabs() { + let input = "a\txbc"; + let pos = position::Position::new(input, 2).unwrap(); + let error: Error<u32> = Error::new_from_pos( + ErrorVariant::ParsingError { + positives: vec![1, 2, 3], + negatives: vec![4, 5, 6], + }, + pos, + ) + .with_path("file.rs"); + + assert_eq!( + format!("{}", error), + vec![ + " --> file.rs:1:3", + " |", + "1 | a xbc", + " | ^---", + " |", + " = unexpected 4, 5, or 6; expected 1, 2, or 3", + ] + .join("\n") + ); + } +} |