diff --git a/src/mango/lexing/code_lexer.rs b/src/mango/lexing/code_lexer.rs
index 1fc8bb29..26fccf7c 100644
--- a/src/mango/lexing/code_lexer.rs
+++ b/src/mango/lexing/code_lexer.rs
@@ -20,10 +20,11 @@ enum ReaderOrDelegate {
 }
 
 impl ReaderOrDelegate {
-    fn end_delegation(&mut self) {
-        *self = match self {
-            ReaderOrDelegate::Delegate(delegate) => ReaderOrDelegate::Reader(delegate.consume()),
-            ReaderOrDelegate::Reader(reader) => ReaderOrDelegate::Reader(*reader),
+    fn end_delegation(self) -> Self {
+        use self::ReaderOrDelegate::*;
+        match self {
+            Delegate(delegate) => Reader(delegate.consume()),
+            read => read,
         }
     }
 }
@@ -87,7 +88,7 @@ impl Lexer for CodeLexer {
                 }
                 // Code to stop delegation cannot be here, because `self` is still mutably borrowed through `delegate`
             }
-            ReaderOrDelegate::Reader(mut reader) => {
+            ReaderOrDelegate::Reader(ref mut reader) => {
                 // todo: maybe this branch could be a separate function?
 
                 // If there is a buffer due to indentation or continuations, return from that.
diff --git a/src/mango/lexing/string_lexer.rs b/src/mango/lexing/string_lexer.rs
index d3f0cf2b..de5c72da 100644
--- a/src/mango/lexing/string_lexer.rs
+++ b/src/mango/lexing/string_lexer.rs
@@ -30,6 +30,7 @@ impl StringLexer {
 
 impl Lexer for StringLexer {
     fn lex(&mut self) -> MaybeToken {
+        // TODO: perhaps there's a library that does parsing a string with escape characters
         // TODO: doesn't handle escaping etc at all now
         // TODO: this is going to have a problem if `matches` automatically eats whitespace
         match self.reader.matches("[^\"\\n]*") {