Switch to i32 for tracking bracket depth.

src/parser/org_source.rs

@@ -19,9 +19,9 @@ pub struct OrgSource<'s> {
     start_of_line: usize,
     preceding_character: Option<char>,
     line_number: usize,
-    bracket_depth: isize,     // []
-    brace_depth: isize,       // {}
-    parenthesis_depth: isize, // ()
+    bracket_depth: i32,     // []
+    brace_depth: i32,       // {}
+    parenthesis_depth: i32, // ()
 }
 
 impl<'s> std::fmt::Debug for OrgSource<'s> {
@@ -77,15 +77,15 @@ impl<'s> OrgSource<'s> {
         self.line_number
     }
 
-    pub fn get_bracket_depth(&self) -> isize {
+    pub fn get_bracket_depth(&self) -> i32 {
         self.bracket_depth
     }
 
-    pub fn get_brace_depth(&self) -> isize {
+    pub fn get_brace_depth(&self) -> i32 {
         self.brace_depth
     }
 
-    pub fn get_parenthesis_depth(&self) -> isize {
+    pub fn get_parenthesis_depth(&self) -> i32 {
         self.parenthesis_depth
     }
 }