Fixed issues with selecting over tab characters

kaolinite/src/document/mod.rs

@@ -259,9 +259,13 @@ impl Document {
         // Account for double width characters
         idx = idx.saturating_sub(self.dbl_map.count(loc, true).unwrap_or(0));
         // Account for tab characters
-        idx = idx.saturating_sub(
-            self.tab_map.count(loc, true).unwrap_or(0) * self.tab_width.saturating_sub(1),
-        );
+        let tabs_behind = self.tab_map.count(loc, true).unwrap_or(0);
+        idx = if let Some(inner_idx) = self.tab_map.inside(self.tab_width, loc.x, loc.y) {
+            let existing_tabs = tabs_behind.saturating_sub(1) * self.tab_width.saturating_sub(1);
+            idx.saturating_sub(existing_tabs + inner_idx)
+        } else {
+            idx.saturating_sub(tabs_behind * self.tab_width.saturating_sub(1))
+        };
         idx
     }
 

kaolinite/src/map.rs

@@ -4,6 +4,7 @@ use std::collections::HashMap;
 use unicode_width::UnicodeWidthChar;
 
 /// This is a type for making a note of the location of different characters
+/// `HashMap`<`y_pos`, Vec<(display, character)>>
 type CharHashMap = HashMap<usize, Vec<(usize, usize)>>;
 
 /// Keeps notes of specific characters within a document for the purposes of double width and
@@ -166,6 +167,17 @@ impl CharMap {
         }
         Some(ctr)
     }
+
+    /// If all character maps are of size n, then determine if x would be within one, and return their index inside the char
+    #[must_use]
+    pub fn inside(&self, n: usize, x: usize, y: usize) -> Option<usize> {
+        for (disp, _) in self.get(y)? {
+            if ((disp + 1)..(disp + n)).contains(&&x) {
+                return Some(x.saturating_sub(*disp));
+            }
+        }
+        None
+    }
 }
 
 /// Vector that takes two usize values