mathengine_parser/
error.rs

1use mathengine_lexer::Token;
2use std::fmt;
3
4#[derive(Debug, Clone, PartialEq)]
5pub enum ParseError {
6    UnexpectedToken {
7        expected: String,
8        found: Token,
9        position: usize,
10    },
11    UnexpectedEndOfInput {
12        expected: String,
13    },
14    InvalidExpression {
15        message: String,
16        position: usize,
17    },
18    EmptyTokenStream,
19}
20
21impl fmt::Display for ParseError {
22    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
23        match self {
24            ParseError::UnexpectedToken {
25                expected,
26                found,
27                position,
28            } => {
29                write!(
30                    f,
31                    "Expected {} but found {:?} at position {}",
32                    expected, found, position
33                )
34            }
35            ParseError::UnexpectedEndOfInput { expected } => {
36                write!(f, "Expected {} but reached end of input", expected)
37            }
38            ParseError::InvalidExpression { message, position } => {
39                write!(
40                    f,
41                    "Invalid expression at position {}: {}",
42                    position, message
43                )
44            }
45            ParseError::EmptyTokenStream => {
46                write!(f, "Cannot parse empty token stream")
47            }
48        }
49    }
50}
51
52impl std::error::Error for ParseError {}
mathengine_parser/error.rs

mathengine_parser/
error.rs
