chore: improve some docs

assembly/src/library/mod.rs

@@ -547,11 +547,11 @@ mod use_std_kernel {
         ) -> io::Result<()> {
             self.library.write_to_file(path, options)
         }
-        /// Read a directory and recursively create modules from its `masm` files.
-        ///
-        /// For every directory, concatenate the module path with the dir name and proceed.
+
+        /// Create a [KernelLibrary] from a standard Miden Assembly project layout.
         ///
-        /// For every file, pick and compile the ones with `masm` extension; skip otherwise.
+        /// This is essentially a wrapper around [CompiledLibrary::from_dir], which then validates
+        /// that the resulting [CompiledLibrary] is a valid [KernelLibrary].
         pub fn from_dir(
             path: impl AsRef<Path>,
             source_manager: Arc<dyn SourceManager>,

assembly/src/parser/lexer.rs

@@ -58,6 +58,7 @@ macro_rules! pop2 {
 /// guarantee that parsing them will produce meaningful results, it is primarily to assist in
 /// gathering as many errors as possible.
 pub struct Lexer<'input> {
+    /// The [SourceId] of the file being lexed, for use in producing spans in lexer diagnostics
     source_id: SourceId,
 
     /// The scanner produces a sequence of chars + location, and can be controlled