From 0ccfe60072f313c9ba4d6e7689a52f15b8e49e98 Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Tue, 13 Feb 2024 21:29:24 -0500
Subject: [PATCH] feat: support nested void matching

---
 crates/aiken-lang/src/gen_uplc.rs        | 13 +++++++++----
 examples/acceptance_tests/093/aiken.lock |  7 +++++++
 examples/acceptance_tests/093/aiken.toml |  4 ++++
 examples/acceptance_tests/093/lib/foo.ak | 10 ++++++++++
 4 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 examples/acceptance_tests/093/aiken.lock
 create mode 100644 examples/acceptance_tests/093/aiken.toml
 create mode 100644 examples/acceptance_tests/093/lib/foo.ak

diff --git a/crates/aiken-lang/src/gen_uplc.rs b/crates/aiken-lang/src/gen_uplc.rs
index f2b49b2b..86fbeaeb 100644
--- a/crates/aiken-lang/src/gen_uplc.rs
+++ b/crates/aiken-lang/src/gen_uplc.rs
@@ -2568,10 +2568,6 @@ impl<'a> CodeGenerator<'a> {
             let (_, assign) = self.clause_pattern(pattern, subject_tipo, props, then);
             assign
         } else {
-            assert!(
-                !subject_tipo.is_void(),
-                "WHY ARE YOU PATTERN MATCHING ON A NESTED VOID???"
-            );
             match pattern {
                 Pattern::Int { value, .. } => {
                     props.complex_clause = true;
@@ -2700,6 +2696,13 @@ impl<'a> CodeGenerator<'a> {
                             bool(),
                             then,
                         )
+                    } else if subject_tipo.is_void() {
+                        AirTree::clause_guard(
+                            &props.original_subject_name,
+                            AirTree::void(),
+                            void(),
+                            then,
+                        )
                     } else {
                         let (cond, assign) =
                             self.clause_pattern(pattern, subject_tipo, props, then);
@@ -4791,6 +4794,8 @@ impl<'a> CodeGenerator<'a> {
                             .force();
                     }
                     Some(term)
+                } else if tipo.is_void() {
+                    Some(then.lambda("_").apply(Term::var(subject_name)))
                 } else {
                     let condition = if tipo.is_int() {
                         Term::equals_integer()
diff --git a/examples/acceptance_tests/093/aiken.lock b/examples/acceptance_tests/093/aiken.lock
new file mode 100644
index 00000000..6e350cda
--- /dev/null
+++ b/examples/acceptance_tests/093/aiken.lock
@@ -0,0 +1,7 @@
+# This file was generated by Aiken
+# You typically do not need to edit this file
+
+requirements = []
+packages = []
+
+[etags]
diff --git a/examples/acceptance_tests/093/aiken.toml b/examples/acceptance_tests/093/aiken.toml
new file mode 100644
index 00000000..ee909d22
--- /dev/null
+++ b/examples/acceptance_tests/093/aiken.toml
@@ -0,0 +1,4 @@
+name = "thing/thing"
+version = "0.0.0"
+license = "Apache-2.0"
+description = "Aiken contracts for project 'thing/thing'"
diff --git a/examples/acceptance_tests/093/lib/foo.ak b/examples/acceptance_tests/093/lib/foo.ak
new file mode 100644
index 00000000..e997c3ba
--- /dev/null
+++ b/examples/acceptance_tests/093/lib/foo.ak
@@ -0,0 +1,10 @@
+pub fn wow(a: Void) -> Int {
+  when Some(a) is {
+    Some(Void) -> 42
+    None -> 0
+  }
+}
+
+test wow_1() {
+  wow(Void) == 42
+}