Move join_strings into wcstringutil.rs

On the C++ side it lives in wcstringutil.cpp.  We should probably keep
it there until we have ported the entirety of that file.

fish-rust/src/lib.rs

@@ -49,6 +49,7 @@
 mod wchar;
 mod wchar_ext;
 mod wchar_ffi;
+mod wcstringutil;
 mod wgetopt;
 mod wutil;
 

fish-rust/src/wcstringutil.rs

@@ -0,0 +1,30 @@
+//! Helper functions for working with wcstring.
+
+use crate::wchar::{wstr, WString};
+
+/// Joins strings with a separator.
+pub fn join_strings(strs: &[&wstr], sep: char) -> WString {
+    if strs.is_empty() {
+        return WString::new();
+    }
+    let capacity = strs.iter().fold(0, |acc, s| acc + s.len()) + strs.len() - 1;
+    let mut result = WString::with_capacity(capacity);
+    for (i, s) in strs.iter().enumerate() {
+        if i > 0 {
+            result.push(sep);
+        }
+        result.push_utfstr(s);
+    }
+    result
+}
+
+#[test]
+fn test_join_strings() {
+    use crate::wchar::L;
+    assert_eq!(join_strings(&[], '/'), "");
+    assert_eq!(join_strings(&[L!("foo")], '/'), "foo");
+    assert_eq!(
+        join_strings(&[L!("foo"), L!("bar"), L!("baz")], '/'),
+        "foo/bar/baz"
+    );
+}

fish-rust/src/wutil/mod.rs

@@ -6,7 +6,6 @@
 pub mod wcstoi;
 mod wrealpath;
 
-use crate::wchar::{wstr, WString};
 pub(crate) use gettext::{wgettext, wgettext_fmt};
 pub use normalize_path::*;
 pub(crate) use printf::sprintf;
@@ -29,30 +28,3 @@ pub fn perror(s: &str) {
     let _ = stderr.write_all(slice);
     let _ = stderr.write_all(b"\n");
 }
-
-/// Joins strings with a separator.
-pub fn join_strings(strs: &[&wstr], sep: char) -> WString {
-    if strs.is_empty() {
-        return WString::new();
-    }
-    let capacity = strs.iter().fold(0, |acc, s| acc + s.len()) + strs.len() - 1;
-    let mut result = WString::with_capacity(capacity);
-    for (i, s) in strs.iter().enumerate() {
-        if i > 0 {
-            result.push(sep);
-        }
-        result.push_utfstr(s);
-    }
-    result
-}
-
-#[test]
-fn test_join_strings() {
-    use crate::wchar::L;
-    assert_eq!(join_strings(&[], '/'), "");
-    assert_eq!(join_strings(&[L!("foo")], '/'), "foo");
-    assert_eq!(
-        join_strings(&[L!("foo"), L!("bar"), L!("baz")], '/'),
-        "foo/bar/baz"
-    );
-}

fish-rust/src/wutil/normalize_path.rs

@@ -1,5 +1,5 @@
 use crate::wchar::{wstr, WString, L};
-use crate::wutil::join_strings;
+use crate::wcstringutil::join_strings;
 
 /// Given an input path, "normalize" it:
 /// 1. Collapse multiple /s into a single /, except maybe at the beginning.