From a69fea553866dd3af00a5d4a74129e2c83c07834 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Sat, 31 Dec 2022 14:00:23 +0100
Subject: [PATCH] Errors - ErrorHandler now includes info about the stage that
failed
---
src/errors.rs | 28 +++++++++++++++++++---------
src/main.rs | 13 ++++++++-----
src/scanner.rs | 12 +++++++++---
3 files changed, 36 insertions(+), 17 deletions(-)
diff --git a/src/errors.rs b/src/errors.rs
index 7d9db21..c67869d 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -1,25 +1,36 @@
use crate::tokens::{Token, TokenType};
+/// The type of an error.
+#[derive(Clone, Copy, Debug)]
+pub enum ErrorType {
+ /// The error occurred while parsing the source code.
+ Parse,
+ /// The error occurred while trying to run the program.
+ Runtime,
+}
+
/// Error handler. Can be used to print error messages; will also retain the
/// current error status.
#[derive(Default, Debug)]
pub struct ErrorHandler {
- had_error: bool,
+ had_error: Option<ErrorType>,
}
impl ErrorHandler {
/// Check whether this handler reported an error.
- pub fn had_error(&self) -> bool {
+ pub fn had_error(&self) -> Option<ErrorType> {
self.had_error
}
/// Report an error.
- pub fn error(&mut self, line: usize, message: &str) {
- self.report(line, "", message)
+ pub fn error(&mut self, err_type: ErrorType, line: usize, message: &str) {
+ self.report(err_type, line, "", message)
}
- fn report(&mut self, line: usize, pos: &str, message: &str) {
- self.had_error = true;
+ fn report(&mut self, err_type: ErrorType, line: usize, pos: &str, message: &str) {
+ if self.had_error.is_none() {
+ self.had_error = Option::Some(err_type);
+ }
println!("[line {line}] Error{pos}: {message}")
}
}
@@ -49,11 +60,10 @@ impl ParserError {
/// Report the error to an error handler.
pub fn report(&self, err_hdl: &mut ErrorHandler) {
- err_hdl.report(self.line, &self.pos, &self.message);
+ err_hdl.report(ErrorType::Parse, self.line, &self.pos, &self.message);
}
}
-
/// An error that occurred while trying to evaluate the code.
#[derive(Debug, Clone)]
pub struct InterpreterError {
@@ -72,6 +82,6 @@ impl InterpreterError {
/// Report the error to an error handler.
pub fn report(&self, err_hdl: &mut ErrorHandler) {
- err_hdl.report(self.line, "", &self.message);
+ err_hdl.report(ErrorType::Runtime, self.line, "", &self.message);
}
}
diff --git a/src/main.rs b/src/main.rs
index c3e7a7a..7ba4541 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -12,7 +12,7 @@ use std::{
};
use ast::AstDumper;
-use errors::ErrorHandler;
+use errors::{ErrorHandler, ErrorType};
use interpreter::evaluate;
use parser::Parser;
use scanner::Scanner;
@@ -72,13 +72,16 @@ fn main() -> Result<(), ExitCode> {
let args: Vec<String> = env::args().skip(1).collect();
let n_args = args.len();
if n_args == 0 {
- run_prompt()
+ run_prompt();
+ Ok(())
} else if n_args == 1 {
- if run_file(&args[0]).had_error() {
- return Err(ExitCode::from(65));
+ match run_file(&args[0]).had_error() {
+ None => Ok(()),
+ Some(ErrorType::Parse) => Err(ExitCode::from(65)),
+ Some(ErrorType::Runtime) => Err(ExitCode::from(70)),
}
} else {
println!("Usage: slox [script]");
+ Err(ExitCode::from(1))
}
- Ok(())
}
diff --git a/src/scanner.rs b/src/scanner.rs
index 5228002..f9dcf38 100644
--- a/src/scanner.rs
+++ b/src/scanner.rs
@@ -3,6 +3,7 @@ use std::collections::HashMap;
use lazy_static::lazy_static;
use crate::{
+ errors::ErrorType,
tokens::{Token, TokenType},
ErrorHandler,
};
@@ -135,7 +136,11 @@ impl Scanner {
// Identifiers
ch if ch.is_ascii_alphabetic() => self.identifier(),
// Anything else is an error
- ch => err_hdl.error(self.line, &format!("unexpected character {:#?}", ch)),
+ ch => err_hdl.error(
+ ErrorType::Parse,
+ self.line,
+ &format!("unexpected character {:#?}", ch),
+ ),
}
}
@@ -153,7 +158,7 @@ impl Scanner {
}
if self.is_at_end() {
- err_hdl.error(self.line, "unterminated string");
+ err_hdl.error(ErrorType::Parse, self.line, "unterminated string");
} else {
self.current += 1; // Last '"'
let value = self.get_substring(self.start + 1, self.current - 1);
@@ -177,6 +182,7 @@ impl Scanner {
match tok_string.parse::<f64>() {
Err(e) => {
err_hdl.error(
+ ErrorType::Parse,
self.line,
&format!(
"Could not parse {} as a floating point number: {:?}",
@@ -207,7 +213,7 @@ impl Scanner {
let mut depth = 1;
loop {
if self.is_at_end() {
- err_hdl.error(self.line, "unterminated block comment");
+ err_hdl.error(ErrorType::Parse, self.line, "unterminated block comment");
return;
}