Fix some formatting issues, mostly around comments and whitespace.

src/eval.rs

@@ -1,5 +1,5 @@
 //! Helpful functions for evaluating NGR programs.
-//! 
+//!
 //! Look, this is a compiler, and so you might be asking why it has a bunch of
 //! stuff in it to help with writing interpreters. Well, the answer is simple:
 //! testing. It's really nice to know that if you start with a program that
@@ -9,15 +9,15 @@
 //! programs don't do 100% the same things in the same order, but you shouldn't
 //! be able to observe the difference ... at least, not without a stopwatch,
 //! memory profilers, etc.
-//! 
+//!
 //! The actual evaluators for our various syntaxes are hidden in `eval` functions
 //! of the various ASTs. It's nice to have them "next to" the syntax that way, so
 //! that we just edit stuff in one part of the source tree at a time. This module,
 //! then, just contains some things that are generally helpful across all the
 //! interpreters we've written.
-//! 
+//!
 //! In particular, this module helps with:
-//! 
+//!
 //!   * Defining a common error type -- [`EvalError`] -- that we can reasonably
 //!     compare. It's nice to compare errors, here, because we want to know that
 //!     if a program used to fail, it will still fail after we change it, and
@@ -45,7 +45,7 @@ pub use value::Value;
 use crate::backend::BackendError;
 
 /// All of the errors that can happen trying to evaluate an NGR program.
-/// 
+///
 /// This is yet another standard [`thiserror::Error`] type, but with the
 /// caveat that it implements [`PartialEq`] even though some of its
 /// constituent members don't. It does so through the very sketchy mechanism
@@ -102,17 +102,17 @@ impl PartialEq for EvalError {
             EvalError::Linker(a) => match other {
                 EvalError::Linker(b) => a == b,
                 _ => false,
-            }
+            },
 
             EvalError::ExitCode(a) => match other {
                 EvalError::ExitCode(b) => a == b,
                 _ => false,
-            }
+            },
 
             EvalError::RuntimeOutput(a) => match other {
                 EvalError::RuntimeOutput(b) => a == b,
                 _ => false,
-            }
+            },
         }
     }
 }