Refactor + introduce eval_deep

src/eval.rs

@@ -665,6 +665,29 @@ pub fn eval_full<R>(
     global_env: &Environment,
     resolver: &mut R,
 ) -> Result<RichTerm, EvalError>
+where
+    R: ImportResolver,
+{
+    eval_internal(t0, global_env, resolver).map(|(term, env)| subst(term, global_env, &env))
+}
+
+/// Fully evaluates a Nickel term like `eval_full`, but does not substitute all variables.
+pub fn eval_deep<R>(
+    t0: RichTerm,
+    global_env: &Environment,
+    resolver: &mut R,
+) -> Result<RichTerm, EvalError>
+where
+    R: ImportResolver,
+{
+    eval_internal(t0, global_env, resolver).map(|(term, _)| term)
+}
+
+fn eval_internal<R>(
+    t0: RichTerm,
+    global_env: &Environment,
+    resolver: &mut R,
+) -> Result<(RichTerm, Environment), EvalError>
 where
     R: ImportResolver,
 {
@@ -681,7 +704,6 @@ where
         ),
     );
     eval_closure(Closure::atomic_closure(wrapper), global_env, resolver, true)
-        .map(|(term, env)| subst(term, global_env, &env))
 }
 
 /// Evaluate a Nickel Term, stopping when a meta value is encountered at the top-level without

src/program.rs

@@ -89,6 +89,13 @@ impl Program {
         eval::eval_full(t, &global_env, &mut self.cache).map_err(|e| e.into())
     }
 
+    /// Same as `eval`, but proceeds to a full evaluation.
+    /// Same as `eval_full`, but does not substitute all variables.
+    pub fn eval_deep(&mut self) -> Result<RichTerm, Error> {
+        let (t, global_env) = self.prepare_eval()?;
+        eval::eval_deep(t, &global_env, &mut self.cache).map_err(|e| e.into())
+    }
+
     /// Wrapper for [`query`](./fn.query.html).
     pub fn query(&mut self, path: Option<String>) -> Result<Term, Error> {
         let global_env = self.cache.prepare_stdlib()?;

tests/examples.rs

@@ -8,7 +8,7 @@ fn eval_file(file: &str) -> Result<RichTerm, Error> {
     let mut path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
     path.push(format!("examples/{}", file));
     let mut p = Program::new_from_file(path).expect("could not load file as a program");
-    p.eval_full()
+    p.eval_deep()
 }
 
 #[test]