aboutsummaryrefslogtreecommitdiff
path: root/src/lisp/error.rs
blob: 9e9dc90657cbb5054706e196cfc48e5e5615e908 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
use crate::lisp::{
    expr::{Arity, LispExpr},
    lex::{Span, SpanDisplay},
    number::LispNumber,
};

use std::{fmt, io};

#[derive(Debug)]
pub enum LispError {
    Parse(ParseError),
    Eval(EvalError),
    Stringified(String),
}

impl std::error::Error for LispError {}

impl fmt::Display for LispError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Parse(p) => write!(f, "parse error: {}", p.kind),
            Self::Eval(e) => write!(f, "eval error: {}", e),
            Self::Stringified(s) => write!(f, "{}", s),
        }
    }
}

#[derive(Debug, PartialEq, Clone)]
pub struct ParseError {
    pub span: Span,
    pub kind: ParseErrorKind,
}

impl ParseError {
    pub fn new(span: Span, kind: ParseErrorKind) -> Self {
        Self { span, kind }
    }
    pub fn display(&self, text: &str, file_name: &str) -> String {
        let SpanDisplay { line, col, .. } = SpanDisplay::highlight_span(self.span, text, file_name);
        format!(
            "in file `{}`; line {}, col {}: {}",
            file_name, line, col, self.kind
        )
    }
}

#[derive(Debug, PartialEq, Clone)]
pub enum ParseErrorKind {
    InvalidLiteral,
    InvalidToken,
    InvalidChar(char),
    LiteralParseError,
    MissingCloseParen,
    UnbalancedComma,
    UnexpectedEof,
    UnexpectedToken {
        expected: &'static str,
        found: &'static str,
    },
    UnmatchedParen,
    UnterminatedString,
}

impl fmt::Display for ParseErrorKind {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ParseErrorKind::InvalidChar(ch) => write!(f, "invalid character {}", ch),
            ParseErrorKind::InvalidToken => write!(f, "invalid token"),
            ParseErrorKind::UnexpectedEof => write!(f, "unexpected end of file"),
            ParseErrorKind::InvalidLiteral => write!(f, "invalid literal"),
            ParseErrorKind::UnmatchedParen => write!(f, "unmatched `)`"),
            ParseErrorKind::UnbalancedComma => write!(f, "unbalanced comma"),
            ParseErrorKind::UnexpectedToken { expected, found } => {
                write!(
                    f,
                    "unexpected token, got `{}`, expected `{}`",
                    found, expected
                )
            }
            ParseErrorKind::LiteralParseError => write!(f, "error parsing literal"),
            ParseErrorKind::MissingCloseParen => write!(f, "missing `)`"),
            ParseErrorKind::UnterminatedString => write!(f, "unterminated string literal"),
        }
    }
}

impl From<ParseError> for LispError {
    fn from(p: ParseError) -> Self {
        LispError::Parse(p)
    }
}

#[derive(Debug)]
pub enum EvalError {
    ArgumentCount(Arity),
    BadForm,
    UnboundVariable(String),
    DivByZero,
    TypeMismatch,
    NoFileName,
    FileError(io::Error),
    AccessEmptyList,
    InvalidCoordinates((LispNumber, LispNumber)),
    AssertionError { expected: LispExpr, got: LispExpr },
    ScriptLoadError(io::Error),
    CustomInternal(&'static str),
    Custom(String),
}

impl fmt::Display for EvalError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::ArgumentCount(i) => {
                write!(f, "invalid number of arguments, expected ")?;
                match i {
                    Arity::Exact(a) => write!(f, "exactly {} argument(s)", a),
                    Arity::Atleast(a) => write!(f, "atleast {} argument(s)", a),
                    Arity::Atmost(a) => write!(f, "atmost {} argument(s)", a),
                    Arity::Range(low, high) => {
                        write!(f, "between {} and {} argument(s)", low, high)
                    }
                    Arity::None => write!(f, "any number of arguments"),
                }
            }
            Self::BadForm => write!(f, "bad expression form"),
            Self::UnboundVariable(s) => write!(f, "unbound variable {}", s),
            Self::TypeMismatch => write!(f, "mismatched types"),
            Self::DivByZero => write!(f, "attempt to divide by zero"),
            Self::NoFileName => write!(f, "no file name specified"),
            Self::FileError(e) => write!(f, "file error: {}", e),
            Self::AccessEmptyList => write!(f, "attempted to access empty list"),
            Self::InvalidCoordinates((x, y)) => write!(f, "invalid coordinates: {} {}", x, y),
            Self::AssertionError { expected, got } => {
                write!(f, "assertion error: expected `{}` got `{}`", expected, got)
            }
            Self::ScriptLoadError(s) => write!(f, "error while loading script: {}", s),
            Self::CustomInternal(s) => write!(f, "{}", s),
            Self::Custom(s) => write!(f, "error: {}", s),
        }
    }
}

impl From<EvalError> for LispError {
    fn from(e: EvalError) -> Self {
        LispError::Eval(e)
    }
}