1 files changed, 27 insertions, 31 deletions

diff --git a/src/lexer.rs b/crates/brainf_lexer/src/lexer.rs
index 786c873..b95cd87 100644
--- a/src/lexer.rs
+++ b/crates/brainf_lexer/src/lexer.rs
@@ -1,40 +1,60 @@
-//! Lexer for Brainfuck
+//! Lexer implementation using logos.
+
+#![expect(clippy::indexing_slicing)]
+
+use logos::{Lexer, Logos};
 
 /// List of operator codes for the lexer
 /// Note: Any input symbol that is not in this list is a comment
-#[derive(Clone, Copy, Debug)]
-pub enum OperatorCode {
+
+fn loop_callback(lex: &Lexer<Token>) -> (usize, usize) {
+	let span = lex.span();
+
+	(span.start, span.len())
+}
+
+/// List of Tokens for the lexer
+/// Note: Any input symbol that is not in this list is a comment
+#[derive(Clone, Copy, Debug, Logos, PartialEq, Eq)]
+#[logos(skip r"[^<>+\-.,\[\]]+")]
+pub enum Token {
 	/// `>`
 	///
 	/// Increment the data pointer by one (to point to the next cell to the
 	/// right).
+	#[token(">")]
 	IncrementPointer,
 
 	/// `<`
 	///
 	/// Decrement the data pointer by one (to point to the next cell to the
 	/// left).
+	#[token("<")]
 	DecrementPointer,
 
 	/// `+`
 	///
 	/// Increment the byte at the data pointer by one.
+	#[token("+")]
 	IncrementByte,
 
 	/// `-`
 	///
 	/// Decrement the byte at the data pointer by one.
+	#[token("-")]
 	DecrementByte,
 
 	/// `.`
 	///
 	/// Output the byte at the data pointer.
+	#[token(".")]
 	OutputByte,
 
 	/// `,`
 	///
 	/// Accept one byte of input, storing its value in the byte at the data
 	/// pointer.
+	#[token(",")]
 	InputByte,
 
 	/// `[`
@@ -42,38 +62,14 @@ pub enum OperatorCode {
 	/// If the byte at the data pointer is zero, then instead of moving the
 	/// instruction pointer forward to the next command, jump it forward to the
 	/// command after the matching ] command.
-	StartLoop {
-		/// Offset of the bracket in the source.
-		offset: usize,
-	},
+	#[token("[", loop_callback)]
+	StartLoop((usize, usize)),
 
 	/// `]`
 	///
 	/// If the byte at the data pointer is nonzero, then instead of moving the
 	/// instruction pointer forward to the next command, jump it back to the
 	/// command after the matching [ command.
-	EndLoop {
-		/// Offset of the bracket in the source.
-		offset: usize,
-	},
-}
-
-/// Perform lexical analysis on the input brainfuck code
-#[must_use]
-pub fn lex(input: &str) -> Vec<OperatorCode> {
-	input
-		.char_indices()
-		.filter_map(|(i, symbol)| match symbol {
-			'>' => Some(OperatorCode::IncrementPointer),
-			'<' => Some(OperatorCode::DecrementPointer),
-			'+' => Some(OperatorCode::IncrementByte),
-			'-' => Some(OperatorCode::DecrementByte),
-			'.' => Some(OperatorCode::OutputByte),
-			',' => Some(OperatorCode::InputByte),
-			'[' => Some(OperatorCode::StartLoop { offset: i }),
-			']' => Some(OperatorCode::EndLoop { offset: i }),
-			// Any symbol that does not match one of the above is a comment
-			_ => None,
-		})
-		.collect()
+	#[token("]", loop_callback)]
+	EndLoop((usize, usize)),
 }