Error if empty list is passed to set selection

kakplugin/src/errors.rs

@@ -16,6 +16,8 @@ pub enum KakError {
     NotImplemented(&'static str),
     /// Custom error string
     Custom(String),
+    /// The selections/selections_desc list passed was empty
+    SetEmptySelections,
 }
 
 impl KakError {
@@ -28,6 +30,9 @@ impl KakError {
             Self::Io(e) => format!("{e:?}"),
             Self::NotImplemented(e) => e.to_string(),
             Self::Custom(s) => s.clone(),
+            Self::SetEmptySelections => {
+                String::from("Attempted to set selections/selections_desc to empty list")
+            }
         }
     }
 }
@@ -44,6 +49,8 @@ impl ToString for KakError {
                 Self::Io(_) => "IO error",
                 Self::NotImplemented(_) => "Not Implemented",
                 Self::Custom(s) => s,
+                Self::SetEmptySelections =>
+                    "Attempted to set selections/selections_desc to empty list",
             }
         )
     }

kakplugin/src/lib.rs

@@ -96,9 +96,14 @@ where
     I: IntoIterator<Item = &'a S>,
     S: AsRef<str>,
 {
+    let mut selections_iter = selections.into_iter().peekable();
+    if selections_iter.peek().is_none() {
+        return Err(KakError::SetEmptySelections);
+    }
+
     let mut f = open_command_fifo()?;
     write!(f, "set-register '\"'")?;
-    for i in selections {
+    for i in selections_iter {
         write!(f, " '{}'", escape(i))?;
     }
     write!(f, "; execute-keys R;")?;
@@ -113,9 +118,14 @@ pub fn set_selections_desc<'a, I>(selections: I) -> Result<(), KakError>
 where
     I: IntoIterator<Item = &'a SelectionDesc>,
 {
+    let mut selections_iter = selections.into_iter().peekable();
+    if selections_iter.peek().is_none() {
+        return Err(KakError::SetEmptySelections);
+    }
+
     let mut f = open_command_fifo()?;
     write!(f, "select")?;
-    for i in selections {
+    for i in selections_iter {
         write!(f, " {}", i)?;
     }
     write!(f, ";")?;