scanner: fix issues regarding peekNext

src/scanner.zig

@@ -186,35 +186,17 @@ pub const Scanner = struct {
 
     /// Peek at the next character in the scanner
     fn peekNext(self: *Scanner) u8 {
-        if (self.current > self.source.len) return 0;
+        if (self.current + 1 > self.source.len) return 0;
         return self.source[self.current];
     }
 
-    /// Skip all whitespace, but increments Scanner.line when finding a newline.
-    fn skipWhitespace(self: *Scanner) void {
-        while (true) {
-            var c = self.peek();
-
-            switch (c) {
-                ' ', '\r', '\t' => blk: {
-                    _ = self.advance();
-                },
-                '\n' => blk: {
-                    self.line += 1;
-                    _ = self.advance();
-                },
-                else => return,
-            }
-        }
-    }
-
     /// Consume a number.
     /// Returns either an Integer or a Float token. Proper typing
     /// of the number (i32 i64 u32 u64 f32 f64) are for the parser.
     fn doNumber(self: *Scanner) Token {
         var ttype = TokenType.Integer;
 
-        while (isDigit(self.peek())) {
+        while (isDigit(self.peekNext())) {
             _ = self.advance();
         }
 
@@ -279,7 +261,6 @@ pub const Scanner = struct {
     }
 
     pub fn nextToken(self: *Scanner) !?Token {
-        self.skipWhitespace();
         self.start = self.current;
 
         if (self.isAtEnd()) return self.makeToken(TokenType.EOF);
@@ -342,6 +323,12 @@ pub const Scanner = struct {
             '\'' => try self.doString('\''),
             '"' => try self.doString('"'),
 
+            ' ', '\r', '\t' => null,
+            '\n' => blk: {
+                self.line += 1;
+                break :blk null;
+            },
+
             else => return ScannerError.Unexpected,
         };