//! # Parser test cases
//!
//! Herein are the test cases for the various parser functions. The suite is
//! partitioned into submodules by combinator cluster, with the large
//! data-driven, span-metadata, internal, and source-span tests broken out
//! separately to keep each file navigable. The deep tests hold the parser, and
//! the deep and wide S-expression tests hold the S-expression reader, to
//! constant stack depth and linear time.