Refactoring

src/lexer/error.rs

@@ -4,17 +4,34 @@ use std::error::Error;
 #[derive(Debug)]
 pub struct LexingError {
 	pub line: usize,
-	pub msg: String,
+	pub kind: LexingErrorKind,
 }
 
 impl fmt::Display for LexingError {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "Error on line: {}", self.line)
+		write!(f, "Error: {}\n on line: {}", self.kind, self.line)
 	}
 }
 
 impl Error for LexingError {
-	fn description(&self) -> &str {
-		&self.msg
+	fn source(&self) -> Option<&(dyn Error + 'static)> {
+		Some(&self.kind)
 	}
 }
+
+#[derive(Debug)]
+pub enum LexingErrorKind {
+	UnmatchedQuote,
+	UnexpectedCharacter(char),
+}
+
+impl fmt::Display for LexingErrorKind {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		match *self {
+			LexingErrorKind::UnmatchedQuote => write!(f, "Unmatched \" character"),
+			LexingErrorKind::UnexpectedCharacter(c) => write!(f, "Unexpected character {c}"),
+		}
+	}
+}
+
+impl Error for LexingErrorKind {}

src/lexer/mod.rs

@@ -5,6 +5,7 @@ use std::str::Chars;
 
 pub use error::LexingError;
 
+use self::error::LexingErrorKind;
 use self::token::Token;
 
 #[derive(Debug)]
@@ -101,14 +102,18 @@ impl<'a> Lexer<'a> {
 				token::TokenType::Greater,
 			),
 			'"' => {
-				let mut string = String::with_capacity(128);
+				let mut string = String::new();
 				let unmatched_char_error = Some(Err(LexingError {
 					line: self.line,
-					msg: "Unmatched \" character".to_string(),
+					kind: LexingErrorKind::UnmatchedQuote,
 				}));
 
 				loop {
-					match self.source_iter.next() {
+					let next_char = self.source_iter.next();
+					if let Some('\n') = next_char {
+						self.line+=1;
+					}
+					match next_char {
 						Some('"') => break,
 						Some('\\') => match self.source_iter.next() {
 							Some(c) => string.push(c),
@@ -120,26 +125,21 @@ impl<'a> Lexer<'a> {
 				}
 				self.get_token(token::TokenType::String(string))
 			}
-			c@'0'..='9' => {
+			c @ '0'..='9' => {
 				let mut num: i64 = c.to_digit(10).unwrap() as i64;
-				while let Some(c) = self.source_iter.peek() {
-					match c {
-						c@'0'..='9' => {
-							num *= 10;
-							num += c.to_digit(10).unwrap() as i64;
-						},
-						_ => break,
-					}
+				while let Some(c) = self.source_iter.next_if(|c| c.is_digit(10)) {
+					num *= 10;
+					num += c.to_digit(10).unwrap() as i64;
 				}
 				self.get_token(token::TokenType::Int(num))
-			},
-			c@'a'..='z' | c@'A'..='Z' => {
-				let mut identifier = String::with_capacity(128);
+			}
+			c @ 'a'..='z' | c @ 'A'..='Z' => {
+				let mut identifier = String::new();
 				identifier.push(c);
 				while let Some(c) = self.source_iter.next_if(|c| c.is_alphanumeric()) {
 					identifier.push(c);
 				}
-				
+
 				self.get_token(match identifier.as_str() {
 					"and" => token::TokenType::And,
 					"else" => token::TokenType::Else,
@@ -154,10 +154,9 @@ impl<'a> Lexer<'a> {
 					"let" => token::TokenType::Let,
 					"While" => token::TokenType::While,
 					"or" => token::TokenType::Or,
-					_ => token::TokenType::Identifier(identifier)
-
+					_ => token::TokenType::Identifier(identifier),
 				})
-			},
+			}
 			// Ignore whitespace
 			' ' | '\r' | '\t' => return None,
 			'\n' => {
@@ -167,7 +166,7 @@ impl<'a> Lexer<'a> {
 			c => {
 				return Some(Err(LexingError {
 					line: self.line,
-					msg: format!("Unexpected character: {c}"),
+					kind: LexingErrorKind::UnexpectedCharacter(c),
 				}))
 			}
 		}))

src/main.rs

@@ -12,7 +12,7 @@ fn run_file(file: &path::Path) -> Result<(), io::Error> {
 }
 
 fn run_repl() {
-	let mut line_buf = String::with_capacity(1024);
+	let mut line_buf = String::new();
 	loop {
 		match io::stdin().read_line(&mut line_buf) {
 			Ok(_) => {