Add NSString::concat and NSString::join_path

Author: madsmtm

objc2/CHANGELOG_FOUNDATION.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * Added `NSBundle`.
 * Added `NSTimeInterval`.
 * Added `NSString::len_utf16` and `NSAttributedString::len_utf16`.
+* Added `NSString::concat` and `NSString::join_path`.
 
 
 ## objc2 0.3.0-beta.2 - 2022-08-28

objc2/src/foundation/string.rs

@@ -56,6 +56,57 @@ extern_methods!(
             unsafe { msg_send_id![Self::class(), new] }
         }
 
+        /// Create a new string by appending the given string to self.
+        ///
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// # #[cfg(feature = "gnustep-1-7")]
+        /// # unsafe { objc2::__gnustep_hack::get_class_to_force_linkage() };
+        /// use objc2::ns_string;
+        /// let error_tag = ns_string!("Error: ");
+        /// let error_string = ns_string!("premature end of file.");
+        /// let error_message = error_tag.concat(error_string);
+        /// assert_eq!(&*error_message, ns_string!("Error: premature end of file."));
+        /// ```
+        #[doc(alias = "stringByAppendingString")]
+        #[doc(alias = "stringByAppendingString:")]
+        pub fn concat(&self, other: &Self) -> Id<Self, Shared> {
+            // SAFETY: The other string is non-null, and won't be retained
+            // by the function.
+            unsafe { msg_send_id![self, stringByAppendingString: other] }
+        }
+
+        /// Create a new string by appending the given string, separated by
+        /// a path separator.
+        ///
+        /// This is similar to [`Path::join`][std::path::Path::join].
+        ///
+        /// Note that this method only works with file paths (not, for
+        /// example, string representations of URLs).
+        ///
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// # #[cfg(feature = "gnustep-1-7")]
+        /// # unsafe { objc2::__gnustep_hack::get_class_to_force_linkage() };
+        /// use objc2::ns_string;
+        ///
+        /// let extension = ns_string!("scratch.tiff");
+        /// assert_eq!(&*ns_string!("/tmp").join_path(extension), ns_string!("/tmp/scratch.tiff"));
+        /// assert_eq!(&*ns_string!("/tmp/").join_path(extension), ns_string!("/tmp/scratch.tiff"));
+        /// assert_eq!(&*ns_string!("/").join_path(extension), ns_string!("/scratch.tiff"));
+        /// assert_eq!(&*ns_string!("").join_path(extension), ns_string!("scratch.tiff"));
+        /// ```
+        #[doc(alias = "stringByAppendingPathComponent")]
+        #[doc(alias = "stringByAppendingPathComponent:")]
+        pub fn join_path(&self, other: &Self) -> Id<Self, Shared> {
+            // SAFETY: Same as `Self::concat`.
+            unsafe { msg_send_id![self, stringByAppendingPathComponent: other] }
+        }
+
         /// The number of UTF-8 code units in `self`.
         #[doc(alias = "lengthOfBytesUsingEncoding")]
         #[doc(alias = "lengthOfBytesUsingEncoding:")]