Add support for nested C-style comments

pj1-go/lexer.go

@@ -183,6 +183,28 @@ func (l *Lexer) scanToken() {
 			for l.peek() != '\n' && !l.atEnd() {
 				l.advance()
 			}
+		} else if l.match('*') {
+			l.advance()
+			l.advance() // swallow the "/*"
+			nesting := 1
+			// A comment goes until we reach */, however,
+			// the comments can also nest
+			for {
+				if l.peek() == '/' && l.peekNext() == '*' {
+					nesting++
+					l.advance()
+					l.advance()
+				} else if l.peek() == '*' && l.peekNext() == '/' {
+					nesting--
+					l.advance()
+					l.advance()
+				} else {
+					if l.peek() == '\n' {
+						l.line++
+					}
+					l.advance()
+				}
+			}
 		} else if l.match('.') {
 			l.addSimpleToken(SLASH_DOT)
 		} else if l.match('_') {