radiance · commit

scanner: Avoid recomputing consumed index

f2ff6b8e805a68a62c8a646a820c370a392df250c46274315ad646fabdc952f3

`advance` incremented the cursor before loading the consumed byte.
Each call therefore subtracted one from the updated cursor.

Load the byte first and then increment the cursor. This removes
redundant arithmetic from the scanner hot path.

Assisted-by: Codex:gpt-5.6-sol

Alexis Sellier committed 1 month ago 1 parent a902a880

lib/std/lang/scanner.rad +2 -1

    return s.source[s.cursor + 1];
}

/// Advance scanner and return the character that was consumed.
fn advance(s: *mut Scanner) -> u8 {
    let ch = s.source[s.cursor];
    set s.cursor += 1;
    return s.source[s.cursor - 1];
    return ch;
}

/// Consume the expected character if it matches the current position.
fn consume(s: *mut Scanner, expected: u8) -> bool {
    if let c = current(s); c == expected {

257	257		return s.source[s.cursor + 1];
258	258		}
259	259
260	260		/// Advance scanner and return the character that was consumed.
261	261		fn advance(s: *mut Scanner) -> u8 {
	262	+	let ch = s.source[s.cursor];
262	263		set s.cursor += 1;
263		-	return s.source[s.cursor - 1];
	264	+	return ch;
264	265		}
265	266
266	267		/// Consume the expected character if it matches the current position.
267	268		fn consume(s: *mut Scanner, expected: u8) -> bool {
268	269		if let c = current(s); c == expected {