refactor: standarize the use of usize for unsigned integers

usize is used in a lot of places in the code by cast os as u32. To
standarize the usage of unsigned integers, usize is going to be used
in detriment of u32.

Closes #35

Signed-off-by: Thiago Duvanel <thiago.duvanel@usp.br>

src/app.rs

@@ -103,12 +103,7 @@ impl LatestPatchsetsState {
     }
 
     pub fn increment_page(&mut self) {
-        let patchsets_processed: usize = self
-            .lore_session
-            .get_representative_patches_ids()
-            .len()
-            .try_into()
-            .unwrap();
+        let patchsets_processed: usize = self.lore_session.get_representative_patches_ids().len();
         if self.page_size * self.page_number > patchsets_processed {
             return;
         }
@@ -399,7 +394,6 @@ impl App {
         let target_list = self.mailing_list_selection_state.possible_mailing_lists[list_index]
             .get_name()
             .to_string();
-
         self.latest_patchsets_state = Some(LatestPatchsetsState::new(
             target_list,
             self.config.page_size,

src/lore_session.rs

@@ -123,10 +123,7 @@ impl LoreSession {
 
     pub fn get_patch_feed_page(&self, page_size: usize, page_number: usize) -> Option<Vec<&Patch>> {
         let mut patch_feed_page: Vec<&Patch> = Vec::new();
-            let representative_patches_ids_max_index: usize = (self.representative_patches_ids.len()
-                - 1)
-            .try_into()
-            .unwrap();
+        let representative_patches_ids_max_index: usize = self.representative_patches_ids.len() - 1;
         let lower_end: usize = page_size * (page_number - 1);
         let mut upper_end: usize = page_size * page_number;
 

src/ui.rs

@@ -213,9 +213,7 @@ fn render_list(f: &mut Frame, app: &App, chunk: Rect) {
 
     let mut list_state = ListState::default();
     list_state.select(Some(
-        (patchset_index - (page_number - 1) * app.config.page_size)
-            .try_into()
-            .unwrap(),
+        patchset_index - (page_number - 1) * app.config.page_size,
     ));
 
     f.render_stateful_widget(list, chunk, &mut list_state);