Disallow empty all

tree_unique_args/src/disallow_empty_all.egg

@@ -0,0 +1,3 @@
+(rule ((ExprIsValid (All order (Nil))))
+      ((panic "UnitExpr should be used instead of an empty All"))
+      :ruleset error-checking)

tree_unique_args/src/disallow_empty_all.rs

@@ -0,0 +1,7 @@
+#[test]
+#[should_panic]
+fn empty_all_should_panic() {
+    let build = "(ExprIsValid (All (Parallel) (Nil)))";
+    let check = "";
+    let _ = crate::run_test(build, check);
+}

tree_unique_args/src/lib.rs

@@ -2,6 +2,7 @@ pub mod ast;
 pub(crate) mod body_contains;
 pub(crate) mod conditional_invariant_code_motion;
 pub(crate) mod deep_copy;
+pub(crate) mod disallow_empty_all;
 pub(crate) mod function_inlining;
 pub(crate) mod id_analysis;
 pub mod interpreter;
@@ -142,6 +143,7 @@ pub fn run_test(build: &str, check: &str) -> Result {
             include_str!("sugar.egg"),
             &util::rules().join("\n"),
             &id_analysis::id_analysis_rules().join("\n"),
+            include_str!("disallow_empty_all.egg"),
             // optimizations
             include_str!("simple.egg"),
             include_str!("function_inlining.egg"),