moo

1 files changed, 15 insertions, 15 deletions

diff --git a/src/launcher/strsub.rs b/src/launcher/strsub.rs
index a50555d..cdf395b 100644
--- a/src/launcher/strsub.rs
+++ b/src/launcher/strsub.rs
@@ -1,6 +1,8 @@
 // a cheap-o implementation of StrSubstitutor from apache commons
 // (does not need to support recursive evaluation or preserving escapes, it was never enabled in
 
+use std::borrow::Cow;
+
 const ESCAPE: char = '$';
 const VAR_BEGIN: &str = "${";
 const VAR_END: &str = "}";
@@ -11,9 +13,9 @@ fn prev_char(slice: &str, idx: usize) -> Option<(usize, char)> {
 }
 
 // basically the same thing as replace_string, but it creates the String itself and returns it.
-pub fn replace_str<T>(input: &str, sub: T) -> String
+pub fn replace_str<'rep, T>(input: &str, sub: T) -> String
 where
-    T: Fn(/*key: */ &str) -> Option<String>
+    T: Fn(/*key: */ &str) -> Option<Cow<'rep, str>>
 {
     let mut input = String::from(input);
     replace_string(&mut input, sub);
@@ -23,21 +25,19 @@ where
 // handles ${replacements} on this string IN-PLACE. Calls the "sub" function for each key it receives.
 // if "sub" returns None, it will use a default value or ignore the ${substitution}.
 // There are no "invalid inputs" and this function should never panic unless "sub" panics.
-pub fn replace_string<T>(input: &mut String, sub: T)
+pub fn replace_string<'rep, T>(input: &mut String, sub: T)
 where
-    T: Fn(/*key: */ &str) -> Option<String>
+    T: Fn(/*key: */ &str) -> Option<Cow<'rep, str>>
 {
     let mut cursor = input.len();
     while let Some(idx) = input[..cursor].rfind(VAR_BEGIN) {
         // note: for some reason, apache processes escapes BEFORE checking if it's even a valid
         // replacement expression. strange behavior IMO.
-        if let Some((pidx, pc)) = prev_char(input.as_ref(), idx) {
-            if pc == ESCAPE {
-                // this "replacement" is escaped. remove the escape marker and continue.
-                input.remove(pidx);
-                cursor = pidx;
-                continue;
-            }
+        if let Some((pidx, ESCAPE)) = prev_char(input.as_ref(), idx) {
+            // this "replacement" is escaped. remove the escape marker and continue.
+            input.remove(pidx);
+            cursor = pidx;
+            continue;
         }
 
         let Some(endidx) = input[idx..cursor].find(VAR_END).map(|v| v + idx) else {
@@ -58,7 +58,7 @@ where
             def_opt = None;
         }
 
-        if let Some(sub_val) = sub(name).map_or_else(|| def_opt.map(|d| d.to_owned()), |v| Some(v)) {
+        if let Some(sub_val) = sub(name).map_or_else(|| def_opt.map(|d| Cow::Owned(d.to_owned())), |v| Some(v)) {
             input.replace_range(idx..(endidx + VAR_END.len()), sub_val.as_ref());
         }
 
@@ -70,11 +70,11 @@ where
 mod tests {
     use super::*;
 
-    fn replace_fun(key: &str) -> Option<String> {
+    fn replace_fun(key: &str) -> Option<Cow<'static, str>> {
         match key {
-            "exists" => Some("value123".into()),
+            "exists" => Some(Cow::Borrowed("value123")),
             "empty" => None,
-            "borger" => Some("\u{1f354}".into()),
+            "borger" => Some(Cow::Borrowed("\u{1f354}")),
             _ => panic!("replace_fun called with unexpected key: {}", key)
         }
     }