Keep track of bracket, brace, and parenthesis depth when iterating over the OrgSource.

src/parser/org_source.rs

@@ -19,6 +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, // ()
 }
 
 impl<'s> OrgSource<'s> {
@@ -33,6 +36,9 @@ impl<'s> OrgSource<'s> {
             start_of_line: 0,
             preceding_character: None,
             line_number: 1,
+            bracket_depth: 0,
+            brace_depth: 0,
+            parenthesis_depth: 0,
         }
     }
 
@@ -62,6 +68,18 @@ impl<'s> OrgSource<'s> {
     pub fn get_line_number(&self) -> usize {
         self.line_number
     }
+
+    pub fn get_bracket_depth(&self) -> isize {
+        self.bracket_depth
+    }
+
+    pub fn get_brace_depth(&self) -> isize {
+        self.brace_depth
+    }
+
+    pub fn get_parenthesis_depth(&self) -> isize {
+        self.parenthesis_depth
+    }
 }
 
 impl<'s> InputTake for OrgSource<'s> {
@@ -127,11 +145,35 @@ where
         let skipped_text = &self.full_source[self.start..new_start];
         let mut start_of_line = self.start_of_line;
         let mut line_number = self.line_number;
+        let mut bracket_depth = self.bracket_depth;
+        let mut brace_depth = self.brace_depth;
+        let mut parenthesis_depth = self.parenthesis_depth;
         for (offset, character) in skipped_text.char_indices() {
-            if character == '\n' {
-                start_of_line = self.start + offset + 1;
-                line_number += 1;
-            }
+            match character {
+                '\n' => {
+                    start_of_line = self.start + offset + 1;
+                    line_number += 1;
+                }
+                '[' => {
+                    bracket_depth += 1;
+                }
+                ']' => {
+                    bracket_depth -= 1;
+                }
+                '{' => {
+                    brace_depth += 1;
+                }
+                '}' => {
+                    brace_depth -= 1;
+                }
+                '(' => {
+                    parenthesis_depth += 1;
+                }
+                ')' => {
+                    parenthesis_depth -= 1;
+                }
+                _ => {}
+            };
         }
 
         OrgSource {
@@ -141,6 +183,9 @@ where
             start_of_line,
             preceding_character: skipped_text.chars().last(),
             line_number,
+            bracket_depth,
+            brace_depth,
+            parenthesis_depth,
         }
     }
 }
@@ -389,4 +434,19 @@ mod tests {
         assert_eq!(input.slice(6..).get_line_number(), 2);
         assert_eq!(input.slice(6..).slice(10..).get_line_number(), 4);
     }
+
+    #[test]
+    fn depth() {
+        let input = OrgSource::new("[][()][({)]}}}}");
+        assert_eq!(input.get_bracket_depth(), 0);
+        assert_eq!(input.get_brace_depth(), 0);
+        assert_eq!(input.get_parenthesis_depth(), 0);
+        assert_eq!(input.slice(4..).get_bracket_depth(), 1);
+        assert_eq!(input.slice(4..).get_brace_depth(), 0);
+        assert_eq!(input.slice(4..).get_parenthesis_depth(), 1);
+        assert_eq!(input.slice(4..).slice(6..).get_bracket_depth(), 1);
+        assert_eq!(input.slice(4..).slice(6..).get_brace_depth(), 1);
+        assert_eq!(input.slice(4..).slice(6..).get_parenthesis_depth(), 0);
+        assert_eq!(input.slice(14..).get_brace_depth(), -2);
+    }
 }