Use proper iterators

src/main.rs

@@ -4,15 +4,30 @@ mod rentry;
 
 const PASTE_NAME: &str = "Hyprland-controversy";
 
-pub struct EditCodeGenerator {
-    codes: Vec<String>,
-    index: usize,
+pub struct EditCodeGenerator<I>
+where
+    I: Iterator<Item = String>,
+{
+    inner: I,
+    last_item: Option<String>,
+    retry: bool,
 }
 
-impl EditCodeGenerator {
+impl<I> EditCodeGenerator<I>
+where
+    I: Iterator<Item = String>,
+{
+    pub fn new(inner: I) -> Self {
+        EditCodeGenerator {
+            inner,
+            last_item: None,
+            retry: false,
+        }
+    }
+
     pub fn retry_last(&mut self) -> Option<()> {
-        if self.index > 0 {
-            self.index -= 1;
+        if let Some(ref _item) = self.last_item {
+            self.retry = true;
             Some(())
         } else {
             None
@@ -20,29 +35,33 @@ impl EditCodeGenerator {
     }
 }
 
-impl Default for EditCodeGenerator {
+impl<I> Iterator for EditCodeGenerator<I>
+where
+    I: Iterator<Item = String>,
+{
+    type Item = String;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.retry {
+            self.retry = false;
+            return self.last_item.clone();
+        }
+
+        let next_item = self.inner.next();
+        self.last_item = next_item.clone();
+        next_item
+    }
+}
+
+impl Default for EditCodeGenerator<std::vec::IntoIter<String>> {
     fn default() -> Self {
         let codes = (b'a'..=b'z')
             .map(|c| (c as char).to_string())
             .chain((b'A'..=b'Z').map(|c| (c as char).to_string()))
             .chain((b'0'..=b'9').map(|c| (c as char).to_string()))
-            .collect();
+            .collect::<Vec<_>>();
 
-        EditCodeGenerator { codes, index: 0 }
-    }
-}
-
-impl Iterator for EditCodeGenerator {
-    type Item = String;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.index < self.codes.len() {
-            let code = self.codes[self.index].clone();
-            self.index += 1;
-            Some(code)
-        } else {
-            None
-        }
+        EditCodeGenerator::new(codes.into_iter())
     }
 }