From 0b7d217bd026be85326db1f2ad65f3f6a7698db7 Mon Sep 17 00:00:00 2001
From: microproofs <kwhitemsg@gmail.com>
Date: Wed, 19 Apr 2023 22:25:55 -0400
Subject: [PATCH] convert acceptance test 8

---
 crates/aiken-project/src/tests/gen_uplc.rs | 32 +++++++++++++++
 crates/uplc/src/builder.rs                 |  4 ++
 crates/uplc/src/optimize.rs                |  7 ++--
 crates/uplc/src/optimize/shrinker.rs       | 47 +++++++++++++++++++++-
 4 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/crates/aiken-project/src/tests/gen_uplc.rs b/crates/aiken-project/src/tests/gen_uplc.rs
index c259ed7c..bb3b8be4 100644
--- a/crates/aiken-project/src/tests/gen_uplc.rs
+++ b/crates/aiken-project/src/tests/gen_uplc.rs
@@ -696,3 +696,35 @@ fn acceptance_test_7_unzip() {
             )),
     );
 }
+
+#[test]
+fn acceptance_test_8_is_empty() {
+    let src = r#"
+      use aiken/builtin
+
+      pub fn is_empty(bytes: ByteArray) -> Bool {
+        builtin.length_of_bytearray(bytes) == 0
+      }
+    
+      test is_empty_1() {
+        is_empty(#"") == True
+      }
+    "#;
+
+    assert_uplc(
+        src,
+        Term::var("is_empty")
+            .lambda("is_empty")
+            .apply(
+                Term::equals_integer()
+                    .apply(Term::length_of_bytearray().apply(Term::var("bytes")))
+                    .apply(Term::integer(0.into()))
+                    .lambda("bytes"),
+            )
+            .apply(Term::byte_string(vec![]))
+            .delayed_if_else(
+                Term::bool(true),
+                Term::bool(true).if_else(Term::bool(false), Term::bool(true)),
+            ),
+    );
+}
diff --git a/crates/uplc/src/builder.rs b/crates/uplc/src/builder.rs
index 5c22c8ae..b24e0280 100644
--- a/crates/uplc/src/builder.rs
+++ b/crates/uplc/src/builder.rs
@@ -135,6 +135,10 @@ impl<T> Term<T> {
         Term::Builtin(DefaultFunction::SubtractInteger)
     }
 
+    pub fn length_of_bytearray() -> Self {
+        Term::Builtin(DefaultFunction::LengthOfByteString)
+    }
+
     pub fn head_list() -> Self {
         Term::Builtin(DefaultFunction::HeadList).force()
     }
diff --git a/crates/uplc/src/optimize.rs b/crates/uplc/src/optimize.rs
index e660d1d5..307d30aa 100644
--- a/crates/uplc/src/optimize.rs
+++ b/crates/uplc/src/optimize.rs
@@ -19,11 +19,12 @@ pub fn aiken_optimize_and_intern(program: Program<Name>) -> Program<Name> {
 
     program
         .lambda_reduce()
-        .inline_reduce()
+        .inline_basic_reduce()
         .lambda_reduce()
-        .inline_reduce()
+        .inline_basic_reduce()
         .force_delay_reduce()
         .wrap_data_reduce()
         .lambda_reduce()
-        .inline_reduce()
+        .inline_basic_reduce()
+        .inline_direct_reduce()
 }
diff --git a/crates/uplc/src/optimize/shrinker.rs b/crates/uplc/src/optimize/shrinker.rs
index a5873ee6..60b95586 100644
--- a/crates/uplc/src/optimize/shrinker.rs
+++ b/crates/uplc/src/optimize/shrinker.rs
@@ -47,9 +47,20 @@ impl Program<Name> {
         }
     }
 
-    pub fn inline_reduce(self) -> Program<Name> {
+    pub fn inline_basic_reduce(self) -> Program<Name> {
         let mut term = self.term;
         inline_basic_reduce(&mut term);
+
+        Program {
+            version: self.version,
+            term,
+        }
+    }
+
+    pub fn inline_direct_reduce(self) -> Program<Name> {
+        let mut term = self.term;
+        inline_direct_reduce(&mut term);
+
         Program {
             version: self.version,
             term,
@@ -160,6 +171,40 @@ fn force_delay_reduce(term: &mut Term<Name>) {
     }
 }
 
+fn inline_direct_reduce(term: &mut Term<Name>) {
+    match term {
+        Term::Delay(d) => {
+            let d = Rc::make_mut(d);
+            inline_direct_reduce(d);
+        }
+        Term::Lambda {
+            parameter_name,
+            body,
+        } => {
+            let body = Rc::make_mut(body);
+            inline_direct_reduce(body);
+
+            if let Term::Var(name) = body {
+                if name.as_ref() == parameter_name.as_ref() {
+                    *term = body.clone();
+                }
+            }
+        }
+        Term::Apply { function, argument } => {
+            let func = Rc::make_mut(function);
+            let arg = Rc::make_mut(argument);
+            inline_direct_reduce(func);
+
+            inline_direct_reduce(arg);
+        }
+        Term::Force(f) => {
+            let f = Rc::make_mut(f);
+            inline_direct_reduce(f);
+        }
+        _ => {}
+    }
+}
+
 fn inline_basic_reduce(term: &mut Term<Name>) {
     match term {
         Term::Delay(d) => {