Working map shift gen

crates/parser/src/rev_mapper/mod.rs

@@ -22,3 +22,35 @@ pub fn find_mapping(
         .filter(|(rust, _)| rust <= target)
         .max_by_key(|(rust, _)| *rust)
 }
+
+impl RustMap {
+    pub fn shifted(self, lines: isize, cols: isize) -> Self {
+        Self(
+            self.0.saturating_add_signed(lines),
+            self.1.saturating_add_signed(cols),
+        )
+    }
+}
+
+impl MistMap {
+    pub fn shifted(self, lines: isize, cols: isize) -> Self {
+        Self(
+            self.0.saturating_add_signed(lines),
+            self.1.saturating_add_signed(cols),
+        )
+    }
+}
+
+pub fn shift_rust_mappings(mappings: &mut HashSet<(RustMap, MistMap)>, lines: isize, cols: isize) {
+    *mappings = mappings
+        .iter()
+        .map(|(rust, mist)| (rust.shifted(lines, cols), *mist))
+        .collect();
+}
+
+pub fn shift_mist_mappings(mappings: &mut HashSet<(RustMap, MistMap)>, lines: isize, cols: isize) {
+    *mappings = mappings
+        .iter()
+        .map(|(rust, mist)| (*rust, mist.shifted(lines, cols)))
+        .collect();
+}