Do not quote \" and \' unnecessarily

src/to_tokens.rs

@@ -24,19 +24,27 @@ impl<T: ToTokens> ToTokens for Option<T> {
     }
 }
 
-macro_rules! impl_to_tokens_debug {
-    ($ty:ty) => {
-        impl ToTokens for $ty {
-            fn to_tokens(&self, tokens: &mut Tokens) {
-                tokens.append(&format!("{:?}", self));
-            }
-        }
-    };
+impl ToTokens for str {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        tokens.append(&format!("{:?}", self).replace("\\'", "'"));
+    }
 }
 
-impl_to_tokens_debug!(str);
-impl_to_tokens_debug!(String);
-impl_to_tokens_debug!(char);
+impl ToTokens for String {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        tokens.append(&format!("{:?}", self).replace("\\'", "'"));
+    }
+}
+
+impl ToTokens for char {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        if *self == '"' {
+            tokens.append("'\"'");
+        } else {
+            tokens.append(&format!("{:?}", self));
+        }
+    }
+}
 
 #[derive(Debug)]
 pub struct ByteStr<'a>(pub &'a str);

tests/test.rs

@@ -156,13 +156,31 @@ fn test_floating() {
 fn test_char() {
     let zero = '\x00';
     let pound = '#';
+    let quote = '"';
+    let apost = '\'';
     let newline = '\n';
     let heart = '\u{2764}';
 
     let tokens = quote! {
-        #zero #pound #newline #heart
+        #zero #pound #quote #apost #newline #heart
     };
-    let expected = "'\\u{0}' '#' '\\n' '\u{2764}' ";
+    let expected = "'\\u{0}' '#' '\"' '\\'' '\\n' '\u{2764}' ";
+    assert_eq!(expected, tokens.to_string());
+}
+
+#[test]
+fn test_str() {
+    let s = "a 'b \" c";
+    let tokens = quote!(#s);
+    let expected = "\"a 'b \\\" c\" ";
+    assert_eq!(expected, tokens.to_string());
+}
+
+#[test]
+fn test_string() {
+    let s = "a 'b \" c".to_string();
+    let tokens = quote!(#s);
+    let expected = "\"a 'b \\\" c\" ";
     assert_eq!(expected, tokens.to_string());
 }