docs: minor logic block explanations

src/nodes/from_str.rs

@@ -61,6 +61,7 @@ impl FromStr for Nodes {
         let filtered_string: String = s.chars().filter(is_not_ignored_char).collect();
 
         for (i, c) in filtered_string.char_indices() {
+            // check whether we're at the end of the bit we're parsing
             match state {
                 ParsingState::Start => {}
                 ParsingState::ReadingFunctionName(start_index) => {
@@ -92,6 +93,7 @@ impl FromStr for Nodes {
                 }
             }
 
+            // start parsing something new (if applicable)
             if state == ParsingState::Start {
                 if is_number_char(c) {
                     state = ParsingState::ReadingNumber(i);
@@ -113,6 +115,7 @@ impl FromStr for Nodes {
             }
         }
 
+        // wrap up any unfinished parsing
         let i = filtered_string.len();
         match state {
             ParsingState::Start => {}