Apply suggestions from code review

Co-authored-by: Nick Rolfe <nickrolfe@github.com>

extractor/src/main.rs

@@ -166,15 +166,15 @@ fn main() -> std::io::Result<()> {
         let mut trap_file = BufWriter::new(trap_file);
         match trap_compression {
             TrapCompression::None => {
-                if erb_trap.is_some() {
-                    write!(trap_file, "{}", erb_trap.unwrap())?;
+                if let Some(erb_trap) = erb_trap {
+                    write!(trap_file, "{}", erb_trap)?;
                 }
                 write!(trap_file, "{}", trap)
             }
             TrapCompression::Gzip => {
                 let mut compressed_writer = GzEncoder::new(trap_file, flate2::Compression::fast());
-                if erb_trap.is_some() {
-                    write!(compressed_writer, "{}", erb_trap.unwrap())?;
+                if let Some(erb_trap) = erb_trap {
+                    write!(compressed_writer, "{}", erb_trap)?;
                 }
                 write!(compressed_writer, "{}", trap)
             }

generator/src/main.rs

@@ -136,6 +136,12 @@ fn add_field_for_column_storage<'a>(
 }
 
 /// Converts the given tree-sitter node types into CodeQL dbscheme entries.
+/// Returns a tuple containing:
+///
+/// 1. A vector of dbscheme entries.
+/// 2. A set of names of the members of the `<lang>_ast_node` union.
+/// 3. A map where the keys are the dbscheme names for token kinds, and the
+/// values are their integer representations.
 fn convert_nodes<'a>(
     nodes: &'a node_types::NodeTypeMap,
 ) -> (Vec<dbscheme::Entry<'a>>, Set<&'a str>, Map<&'a str, usize>) {
@@ -244,6 +250,12 @@ fn convert_nodes<'a>(
 
     (entries, ast_node_members, token_kinds)
 }
+
+/// Creates a dbscheme table entry representing the parent relation for AST nodes.
+///
+/// # Arguments
+/// - `name` - the name of both the table to create and the node parent type.
+/// - `ast_node_name` - the name of the node child type.
 fn create_ast_node_parent_table<'a>(name: &'a str, ast_node_name: &'a str) -> dbscheme::Table<'a> {
     dbscheme::Table {
         name,

generator/src/ql.rs

@@ -249,7 +249,7 @@ impl<'a> fmt::Display for FormalParameter<'a> {
     }
 }
 
-/// Generates a QL library by writing the given `classes` to the `file`.
+/// Generates a QL library by writing the given `elements` to the `file`.
 pub fn write<'a>(file: &mut dyn std::io::Write, elements: &'a [TopLevel]) -> std::io::Result<()> {
     for element in elements {
         write!(file, "{}\n\n", &element)?;