Minor tweaks

src/parser/linelocation.rs

@@ -15,6 +15,14 @@ impl LineLocation {
 	pub fn zero(&self) -> bool {
 		return self.pos == 0 && self.len == 0
 	}
+
+	pub fn new_zero() -> LineLocation {
+		return LineLocation { pos: 0, len: 0}
+	}
+
+	pub fn cut_string<'a>(&self, s: &'a String) -> &'a str {
+		&s[self.pos..self.pos+self.len]
+	}
 }
 
 impl PartialEq for LineLocation {