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use std::fmt;
#[derive(Debug, Clone, PartialEq)]
pub enum Error {
Parse(ParseError),
Context(ContextError),
Eval(EvalError),
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Error::Parse(parse_error) => write!(f, "{}", parse_error),
Error::Context(context_error) => write!(f, "{}", context_error),
Error::Eval(eval_error) => write!(f, "{}", eval_error),
}
}
}
#[derive(Debug, Clone, PartialEq)]
pub struct ParseError {
pub line: usize,
pub message: String,
}
impl std::error::Error for ParseError {}
impl fmt::Display for ParseError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "parser (line {}): {}.", self.line + 1, self.message)
}
}
#[derive(Debug, Clone, PartialEq)]
pub enum ContextErrorReason {
Redefinition,
UnknownVariable,
BadScope,
Label,
Other,
}
#[derive(Debug, Clone, PartialEq)]
pub struct ContextError {
pub line: usize,
pub reason: ContextErrorReason,
pub message: String,
}
impl std::error::Error for ContextError {}
impl fmt::Display for ContextError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"Context error (line {}): {}.",
self.line + 1,
self.message
)
}
}
#[derive(Debug, Clone, PartialEq)]
pub struct EvalError {
pub line: usize,
pub message: String,
pub global: bool,
}
impl std::error::Error for EvalError {}
impl From<ContextError> for EvalError {
fn from(err: ContextError) -> Self {
EvalError {
line: err.line,
message: err.message,
global: false,
}
}
}
impl fmt::Display for EvalError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.global {
write!(f, "Evaluation error: {}.", self.message)
} else {
write!(
f,
"Evaluation error (line {}): {}.",
self.line + 1,
self.message
)
}
}
}
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