FIX: Don not clone Locales and Languages, pass them by reference

xlsx/src/export/test/test_export.rs

@@ -7,7 +7,7 @@ use crate::export::save_to_icalc;
 use crate::import::load_from_icalc;
 use crate::{export::save_to_xlsx, import::load_from_xlsx};
 
-pub fn new_empty_model() -> Model {
+pub fn new_empty_model<'a>() -> Model<'a> {
     Model::new_empty("model", "en", "UTC", "en").unwrap()
 }
 

xlsx/src/import/mod.rs

@@ -140,18 +140,18 @@ pub fn load_from_xlsx_bytes(
 }
 
 /// Loads a [Model] from an xlsx file
-pub fn load_from_xlsx(
+pub fn load_from_xlsx<'a>(
     file_name: &str,
     locale: &str,
     tz: &str,
-    language: &str,
-) -> Result<Model, XlsxError> {
+    language: &'a str,
+) -> Result<Model<'a>, XlsxError> {
     let workbook = load_from_excel(file_name, locale, tz)?;
     Model::from_workbook(workbook, language).map_err(XlsxError::Workbook)
 }
 
 /// Loads a [Model] from an `ic` file (a file in the IronCalc internal representation)
-pub fn load_from_icalc(file_name: &str, language_id: &str) -> Result<Model, XlsxError> {
+pub fn load_from_icalc<'a>(file_name: &str, language_id: &'a str) -> Result<Model<'a>, XlsxError> {
     let contents = fs::read(file_name)
         .map_err(|e| XlsxError::IO(format!("Could not extract workbook name: {e}")))?;
     let workbook: Workbook = bitcode::decode(&contents)