From 14de12944e06f32a440b6ff9d373779da48d3a75 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Fri, 21 Jul 2023 17:00:05 +0300
Subject: [PATCH 01/16] #2283: should work

---
 .../java/org/eolang/maven/rust/Native.java    |  2 +-
 .../org/eolang/maven/rust/PrimeModule.java    |  8 ++-
 .../src/main/java/EOorg/EOeolang/EOrust.java  |  3 +-
 .../src/main/rust/eo_env/src/eo_enum.rs       | 57 +++++++++++++++++++
 eo-runtime/src/main/rust/eo_env/src/eo_env.rs | 28 ++++++++-
 .../src/test/eo/org/eolang/rust-tests.eo      | 10 ++--
 6 files changed, 98 insertions(+), 10 deletions(-)
 create mode 100644 eo-runtime/src/main/rust/eo_env/src/eo_enum.rs

diff --git a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/Native.java b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/Native.java
index 0a6c7a9527..24c34a239f 100644
--- a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/Native.java
+++ b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/Native.java
@@ -75,7 +75,7 @@ public void save(final Footprint footprint) throws IOException {
                     this.name
                 ),
                 String.format(
-                    "    public static native int %s",
+                    "    public static native byte[] %s",
                     this.name
                 ),
                 "        (final EOrust eo);",
diff --git a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
index 5902888377..9918432fe7 100644
--- a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
+++ b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
@@ -42,14 +42,16 @@ public PrimeModule(final String method, final String file) {
                 "mod foo;",
                 "use foo::foo;",
                 "use jni::JNIEnv;",
-                "use jni::objects::{JClass, JObject};",
+                "use jni::objects::{JByteArray, JClass, JObject};",
                 "use jni::sys::{jint};",
                 "use eo_env::EOEnv;",
                 "#[no_mangle]",
                 "pub extern \"system\" fn",
                 String.format("Java_EOrust_natives_%s_%s", method, method),
-                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> jint",
-                "{ return foo(EOEnv::new(env, _class, universe)); }"
+                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> JByteArray",
+                "{ let mut my_env = MyEnv::new(env, _class, universe); ",
+                "let arr = foo(&mut my_env).eo2vec();",
+                "my_env.java_env.byte_array_from_slice(&arr.as_slice()).unwrap() }"
             ),
             file
         );
diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index 1c6d211ab1..4a1c70fb42 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -129,8 +129,9 @@ public EOrust(final Phi sigma) {
                             name
                         )
                     ).getDeclaredMethod(name, new Class[]{EOrust.class});
+                    byte[] res = (byte[]) method.invoke(null, this);
                     return new Data.ToPhi(
-                        Long.valueOf((int) method.invoke(null, this))
+                        Long.valueOf(res.length)
                     );
                 }
             )
diff --git a/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs b/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs
new file mode 100644
index 0000000000..bf6d55eab5
--- /dev/null
+++ b/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs
@@ -0,0 +1,57 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2023 Objectionary.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+pub enum EO {
+    EOVertex(u32),
+    EODouble(f64),
+    EOInt(i64),
+    EOString(String),
+    EORaw(Box<[u8]>),
+}
+
+impl EO {
+    pub fn eo2vec(&self) -> Vec<u8> {
+        match self {
+            EO::EOVertex(v) => {
+                let mut res: Vec<u8> = vec![0; 1 + 4];
+                res[0] = 0;
+                res[1..].copy_from_slice(&v.to_le_bytes());
+                res
+            }
+            EO::EODouble(x) => {
+                let mut res = vec![1; 1 + 8];
+                res[1..].copy_from_slice(&x.to_be_bytes());
+                res
+            }
+            EO::EOInt(x) => {
+                let mut res: Vec<u8> = vec![2; 1 + 8];
+                res[0] = 0;
+                res[1..].copy_from_slice(&x.to_le_bytes());
+                res
+            }
+            EO::EOString(_) => { vec![0xff] }
+            EO::EORaw(_) => { vec![0xff] }
+        }
+    }
+}
diff --git a/eo-runtime/src/main/rust/eo_env/src/eo_env.rs b/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
index 29af75cda2..4057454f2f 100644
--- a/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
+++ b/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
@@ -1,9 +1,34 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2023 Objectionary.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+pub mod eo_enum;
 use jni::JNIEnv;
 use jni::objects::{JClass, JObject, JValue};
 
 #[allow(dead_code)]
 pub struct EOEnv<'local> {
-    java_env: JNIEnv<'local>,
+    pub java_env: JNIEnv<'local>,
     java_class: JClass<'local>,
     java_obj: JObject<'local>
 }
@@ -79,6 +104,7 @@ impl<'local> EOEnv<'_> {
      *  call java dataizing method and get byte array from it.
      *  Then it have to return byte array as a result of dataization.
      */
+    #[allow(unused_variables)]
     pub fn dataize(&mut self, v: u32) -> Option<&[u32]> {
         Some(&[0x0])
     }
diff --git a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
index 0faa9eaa10..816cdaada0 100644
--- a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
+++ b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
@@ -40,8 +40,9 @@
     *
   assert-that > @
     r
-    $.equal-to
-      2
+    $.not
+      $.less-than
+        0
 
 [] > rust-find-returns-int
   QQ.rust > r
@@ -56,8 +57,9 @@
     *
   assert-that > @
     r
-    $.equal-to
-      0
+    $.not
+      $.less-than
+        0
 
 [] > rust-put-not-fails
   QQ.rust > r

From 561798c0144546ba9fa664bca0734b5f0d8c3810 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Fri, 21 Jul 2023 19:43:44 +0300
Subject: [PATCH 02/16] #2283: maven plugin tests fail

---
 .../org/eolang/maven/rust/PrimeModule.java    |  7 +-
 .../org/eolang/maven/BinarizeMojoTest.java    |  5 ++
 .../eolang/maven/BinarizeParseMojoTest.java   |  4 +-
 .../maven/binarize/eo_env/src/eo_env.rs       |  3 +-
 .../org/eolang/maven/binarize/simple-rust.eo  |  2 +-
 .../org/eolang/maven/binarize/twice-rust.eo   |  8 +--
 .../java/org/eolang/parser/SyntaxTest.java    |  2 +-
 .../src/main/java/EOorg/EOeolang/EOrust.java  | 35 +++++++++-
 .../src/main/rust/eo_env/src/eo_enum.rs       | 13 ++--
 .../src/test/eo/org/eolang/rust-tests.eo      | 67 +++++++++++++------
 10 files changed, 105 insertions(+), 41 deletions(-)

diff --git a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
index 9918432fe7..156c94ba76 100644
--- a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
+++ b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
@@ -43,15 +43,14 @@ public PrimeModule(final String method, final String file) {
                 "use foo::foo;",
                 "use jni::JNIEnv;",
                 "use jni::objects::{JByteArray, JClass, JObject};",
-                "use jni::sys::{jint};",
                 "use eo_env::EOEnv;",
                 "#[no_mangle]",
                 "pub extern \"system\" fn",
                 String.format("Java_EOrust_natives_%s_%s", method, method),
                 "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> JByteArray",
-                "{ let mut my_env = MyEnv::new(env, _class, universe); ",
-                "let arr = foo(&mut my_env).eo2vec();",
-                "my_env.java_env.byte_array_from_slice(&arr.as_slice()).unwrap() }"
+                "{ let mut eo_env = EOEnv::new(env, _class, universe); ",
+                "let arr = foo(&mut eo_env).eo2vec();",
+                "eo_env.java_env.byte_array_from_slice(&arr.as_slice()).unwrap() }"
             ),
             file
         );
diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
index 0581a9beb6..919736cc0f 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
@@ -23,6 +23,7 @@
  */
 package org.eolang.maven;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -48,6 +49,8 @@ final class BinarizeMojoTest {
      */
     public static final Path SRC = Paths.get("src/test/resources/org/eolang/maven/binarize/");
 
+    public static final File ENV = new File("../eo-runtime/src/main/rust/eo_env");
+
     /**
      * BinarizeMojo can binarize without errors.
      * @param temp Temporary directory.
@@ -60,6 +63,7 @@ void binarizesWithoutErrors(@TempDir final Path temp) throws Exception {
         final FakeMaven maven;
         synchronized (BinarizeMojoTest.class) {
             maven = new FakeMaven(temp)
+                .with("eoEnvDir", BinarizeMojoTest.ENV)
                 .withProgram(BinarizeMojoTest.SRC.resolve("simple-rust.eo"))
                 .withProgram(BinarizeMojoTest.SRC.resolve("twice-rust.eo"));
         }
@@ -89,6 +93,7 @@ void savesToCache(@TempDir final Path temp) throws IOException {
         final Path cache = temp.resolve(".cache");
         synchronized (BinarizeMojoTest.class) {
             maven = new FakeMaven(temp)
+                .with("eoEnvDir", BinarizeMojoTest.ENV)
                 .withProgram(BinarizeMojoTest.SRC.resolve("simple-rust.eo"))
                 .with("cache", cache);
         }
diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
index c47ed5b81a..2261f3a405 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
@@ -71,7 +71,7 @@ void parsesSimpleEoProgram(@TempDir final Path temp) throws Exception {
             new TextOf(res.get(rust)).asString(),
             Matchers.stringContainsInOrder(
                 "use rand::Rng;",
-                "pub fn foo(mut env: EOEnv<'_>) -> i32 {",
+                "pub fn foo(mut env: EOEnv<'_>) -> EO {",
                 "  let mut rng = rand::thread_rng();",
                 "  print!(\"Hello world\");",
                 "  let i = rng.gen::<i32>();",
@@ -88,7 +88,7 @@ void parsesSimpleEoProgram(@TempDir final Path temp) throws Exception {
                     )
                 )
             ).asString(),
-            Matchers.containsString("public static native int")
+            Matchers.containsString("public static native byte[]")
         );
     }
 
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs
index 7361d82ff6..fb4c07749c 100644
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs
+++ b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs
@@ -1,9 +1,10 @@
+pub mod eo_enum;
 use jni::JNIEnv;
 use jni::objects::{JClass, JObject};
 
 #[allow(dead_code)]
 pub struct EOEnv<'local> {
-    java_env: JNIEnv<'local>,
+    pub java_env: JNIEnv<'local>,
     java_class: JClass<'local>,
     java_obj: JObject<'local>
 }
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
index c8ae6abbaa..b24d990909 100644
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
+++ b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
@@ -7,7 +7,7 @@
     use rand::Rng;
     use eo_env::EOEnv;
 
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    pub fn foo(mut env: EOEnv<'_>) -> EO {
       let mut rng = rand::thread_rng();
       print!("Hello world");
       let i = rng.gen::<i32>();
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
index e5ddaff396..5f3af4f5d1 100644
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
+++ b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
@@ -6,10 +6,10 @@
     """
     use eo_env::EOEnv;
 
-    pub fn foo(mut _env: EOEnv<'_>) -> i32 {
+    pub fn foo(mut _env: EOEnv<'_>) -> EO {
       let x = rand::random::<i32>();
       println!("{}", x);
-      x
+      EOInt(x as i64)
     }
     """
     *
@@ -21,10 +21,10 @@
     """
     use eo_env::EOEnv;
 
-    pub fn foo(mut _env: EOEnv<'_>) -> i32 {
+    pub fn foo(mut _env: EOEnv<'_>) -> EO {
       print!("Hello 大 2");
       let x = rand::random::<i32>();
-      x
+      EOInt(x as i64)
     }
     """
     *
diff --git a/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java b/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
index 00cb9980ae..be471f8bac 100644
--- a/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
+++ b/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
@@ -54,7 +54,7 @@
 final class SyntaxTest {
 
     @Test
-    void parsesSimpleCode() throws Exception {
+    void EOFloatpleCode() throws Exception {
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         final Syntax syntax = new Syntax(
             "test-1",
diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index 4a1c70fb42..aa82c45e83 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -32,8 +32,10 @@
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Arrays;
 import java.util.concurrent.ConcurrentHashMap;
 import org.apache.commons.lang3.NotImplementedException;
 import org.apache.commons.lang3.SystemUtils;
@@ -130,9 +132,7 @@ public EOrust(final Phi sigma) {
                         )
                     ).getDeclaredMethod(name, new Class[]{EOrust.class});
                     byte[] res = (byte[]) method.invoke(null, this);
-                    return new Data.ToPhi(
-                        Long.valueOf(res.length)
-                    );
+                    return EOrust.translate(res);
                 }
             )
         );
@@ -229,4 +229,33 @@ private static ConcurrentHashMap<String, String> load(final String src) throws I
             );
         }
     }
+
+    private static Phi translate(final byte[] message) {
+        final byte determinant = message[0];
+        final byte[] content = Arrays.copyOfRange(message, 1, message.length);
+        final Phi ret;
+        switch (determinant) {
+            case 0:
+                throw new ExFailure(
+                    "Returning vertex is not implemented yet"
+                );
+            case 1:
+                ByteBuffer byteBuffer = ByteBuffer.allocate(Double.BYTES);
+                byteBuffer.put(content);
+                byteBuffer.flip();
+                ret = new Data.ToPhi(byteBuffer.getDouble());
+                break;
+            case 2:
+                byteBuffer = ByteBuffer.allocate(Long.BYTES);
+                byteBuffer.put(content);
+                byteBuffer.flip();
+                ret = new Data.ToPhi(byteBuffer.getLong());
+                break;
+            default:
+                throw new ExFailure(
+                    "Returning Strings and raw bytes is not implemented yet"
+                );
+        }
+        return ret;
+    }
 }
diff --git a/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs b/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs
index bf6d55eab5..4929c7aca0 100644
--- a/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs
+++ b/eo-runtime/src/main/rust/eo_env/src/eo_enum.rs
@@ -24,7 +24,7 @@
 
 pub enum EO {
     EOVertex(u32),
-    EODouble(f64),
+    EOFloat(f64),
     EOInt(i64),
     EOString(String),
     EORaw(Box<[u8]>),
@@ -39,15 +39,16 @@ impl EO {
                 res[1..].copy_from_slice(&v.to_le_bytes());
                 res
             }
-            EO::EODouble(x) => {
-                let mut res = vec![1; 1 + 8];
+            EO::EOFloat(x) => {
+                let mut res = vec![0; 1 + 8];
+                res[0] = 1;
                 res[1..].copy_from_slice(&x.to_be_bytes());
                 res
             }
             EO::EOInt(x) => {
-                let mut res: Vec<u8> = vec![2; 1 + 8];
-                res[0] = 0;
-                res[1..].copy_from_slice(&x.to_le_bytes());
+                let mut res: Vec<u8> = vec![0; 1 + 8];
+                res[0] = 2;
+                res[1..].copy_from_slice(&x.to_be_bytes());
                 res
             }
             EO::EOString(_) => { vec![0xff] }
diff --git a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
index 816cdaada0..66717b0df4 100644
--- a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
+++ b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
@@ -26,32 +26,54 @@
 +package org.eolang
 +version 0.0.0
 
-[] > rust-creates-object
+[] > rust-returns-int
   QQ.rust > r
     """
     use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
 
-    pub fn foo(mut _env: EOEnv<'_>) -> i32 {
+    pub fn foo(_env: &mut EOEnv) -> EO {
       println!("Hello world from rust");
       let x = 4.0_f32;
-      x.sqrt() as i32
+      EOInt(x.sqrt() as i64)
     }
     """
     *
   assert-that > @
     r
-    $.not
-      $.less-than
-        0
+    $.equal-to
+      2
+
+[] > rust-returns-doable
+  QQ.rust > r
+    """
+    use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOFloat};
+
+    pub fn foo(_env: &mut EOEnv) -> EO {
+      println!("Hello world from EOFloat");
+      let x = 4.0_f64;
+      EOFloat(x.sqrt())
+    }
+    """
+    *
+  assert-that > @
+    r
+    $.equal-to
+      2.0
 
 [] > rust-find-returns-int
   QQ.rust > r
     """
     use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
 
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    pub fn foo(env: &mut EOEnv) -> EO {
       env.find("^");
-      0
+      EOInt(0 as i64)
     }
     """
     *
@@ -65,10 +87,11 @@
   QQ.rust > r
     """
     use eo_env::EOEnv;
-
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
+    pub fn foo(env: &mut EOEnv) -> EO {
       env.put(3, &[0x00, 0x1a, 0xEE, 0xf, 0xf3]).unwrap();
-      0
+      EOInt(0 as i64)
     }
     """
     *
@@ -82,11 +105,13 @@
   QQ.rust > insert
     """
     use eo_env::EOEnv;
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
+    pub fn foo(env: &mut EOEnv) -> EO {
         let v1 = env.find("a") as u32;
         let v2 = env.find("b") as u32;
-        env.bind(v1 , v2, "my-att");
-        return v1 as i32;
+        env.bind(v1 , v2, "EO-att");
+        return EOInt(v1 as i64);
     }
     """
     *
@@ -100,10 +125,12 @@
   QQ.rust > copy
     """
     use eo_env::EOEnv;
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
+    pub fn foo(env: &mut EOEnv) -> EO {
         let v = env.find("a") as u32;
         let copy = env.copy(v).unwrap();
-        copy as i32
+        EOInt(copy as i64)
     }
     """
     *
@@ -117,10 +144,12 @@
   QQ.rust > dataized
     """
     use eo_env::EOEnv;
-    pub fn foo(mut env: EOEnv<'_>) -> i32 {
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
+    pub fn foo(env: &mut EOEnv) -> EO {
         let v = env.find("a") as u32;
-        let bytes = env.dataize(v).unwrap();
-        v as i32
+        let _bytes = env.dataize(v).unwrap();
+        EOInt(v as i64)
     }
     """
     *

From 1d9105ee8de3015d2ffaac8a204f391c34b13945 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sat, 22 Jul 2023 23:46:17 +0300
Subject: [PATCH 03/16] #2283: removed eo_env in eo-maven-plugin and leave path
 to eo_env in eo-runtime

---
 .../test/java/org/eolang/maven/FakeMaven.java |  2 +-
 .../eolang/maven/binarize/eo_env/Cargo.toml   | 12 -----------
 .../maven/binarize/eo_env/src/eo_env.rs       | 20 -------------------
 3 files changed, 1 insertion(+), 33 deletions(-)
 delete mode 100644 eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/Cargo.toml
 delete mode 100644 eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs

diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/FakeMaven.java b/eo-maven-plugin/src/test/java/org/eolang/maven/FakeMaven.java
index 4e65f95fae..992db9a0ea 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/FakeMaven.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/FakeMaven.java
@@ -231,7 +231,7 @@ public <T extends AbstractMojo> FakeMaven execute(final Class<T> mojo) throws IO
             this.params.putIfAbsent("objectionary", new Objectionary.Fake());
             this.params.putIfAbsent(
                 "eoEnvDir",
-                new File("src/test/resources/org/eolang/maven/binarize/eo_env")
+                new File("../eo-runtime/src/main/rust/eo_env")
             );
         }
         final Moja<T> moja = new Moja<>(mojo);
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/Cargo.toml b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/Cargo.toml
deleted file mode 100644
index d7f29f7e3a..0000000000
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/Cargo.toml
+++ /dev/null
@@ -1,12 +0,0 @@
-[package]
-name = "eo_env"
-version = "0.1.0"
-edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-jni = "0.21.1"
-
-[lib]
-path = "src/eo_env.rs"
\ No newline at end of file
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs
deleted file mode 100644
index fb4c07749c..0000000000
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/eo_env/src/eo_env.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-pub mod eo_enum;
-use jni::JNIEnv;
-use jni::objects::{JClass, JObject};
-
-#[allow(dead_code)]
-pub struct EOEnv<'local> {
-    pub java_env: JNIEnv<'local>,
-    java_class: JClass<'local>,
-    java_obj: JObject<'local>
-}
-
-impl<'local> EOEnv<'_> {
-    pub fn new(java_env: JNIEnv<'local>, java_class: JClass<'local>, java_obj: JObject<'local>) -> EOEnv<'local> {
-        EOEnv {
-            java_env,
-            java_class,
-            java_obj
-        }
-    }
-}

From a855163508cae34ae70e87ad40ed9245d103078f Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sat, 22 Jul 2023 23:47:17 +0300
Subject: [PATCH 04/16] #2283: updated to new signature of eo_env

---
 .../java/org/eolang/maven/BinarizeMojoTest.java  |  4 ----
 .../org/eolang/maven/BinarizeParseMojoTest.java  | 16 ++++++++++------
 .../org/eolang/maven/binarize/simple-rust.eo     |  8 +++++---
 .../org/eolang/maven/binarize/twice-rust.eo      |  8 ++++++--
 4 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
index 919736cc0f..f0234ad5dc 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
@@ -49,8 +49,6 @@ final class BinarizeMojoTest {
      */
     public static final Path SRC = Paths.get("src/test/resources/org/eolang/maven/binarize/");
 
-    public static final File ENV = new File("../eo-runtime/src/main/rust/eo_env");
-
     /**
      * BinarizeMojo can binarize without errors.
      * @param temp Temporary directory.
@@ -63,7 +61,6 @@ void binarizesWithoutErrors(@TempDir final Path temp) throws Exception {
         final FakeMaven maven;
         synchronized (BinarizeMojoTest.class) {
             maven = new FakeMaven(temp)
-                .with("eoEnvDir", BinarizeMojoTest.ENV)
                 .withProgram(BinarizeMojoTest.SRC.resolve("simple-rust.eo"))
                 .withProgram(BinarizeMojoTest.SRC.resolve("twice-rust.eo"));
         }
@@ -93,7 +90,6 @@ void savesToCache(@TempDir final Path temp) throws IOException {
         final Path cache = temp.resolve(".cache");
         synchronized (BinarizeMojoTest.class) {
             maven = new FakeMaven(temp)
-                .with("eoEnvDir", BinarizeMojoTest.ENV)
                 .withProgram(BinarizeMojoTest.SRC.resolve("simple-rust.eo"))
                 .with("cache", cache);
         }
diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
index 2261f3a405..883955d7ce 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
@@ -71,11 +71,11 @@ void parsesSimpleEoProgram(@TempDir final Path temp) throws Exception {
             new TextOf(res.get(rust)).asString(),
             Matchers.stringContainsInOrder(
                 "use rand::Rng;",
-                "pub fn foo(mut env: EOEnv<'_>) -> EO {",
+                "pub fn foo(_env: &EOEnv) -> EO {",
                 "  let mut rng = rand::thread_rng();",
                 "  print!(\"Hello world\");",
-                "  let i = rng.gen::<i32>();",
-                "  i",
+                "  let i = rng.gen::<i64>();",
+                "  EOInt(i)",
                 "}"
             )
         );
@@ -94,7 +94,7 @@ void parsesSimpleEoProgram(@TempDir final Path temp) throws Exception {
 
     @Test
     void binarizesTwiceRustProgram(@TempDir final Path temp) throws Exception {
-        final Path src = Paths.get("src/test/resources/org/eolang/maven/binarize/twice-rust.eo");
+        final Path src = BinarizeMojoTest.SRC.resolve("twice-rust.eo");
         final FakeMaven maven;
         synchronized (BinarizeParseMojoTest.class) {
             maven = new FakeMaven(temp).withProgram(src);
@@ -119,14 +119,18 @@ void binarizesTwiceRustProgram(@TempDir final Path temp) throws Exception {
         MatcherAssert.assertThat(
             new TextOf(res.get(one)).asString(),
             Matchers.stringContainsInOrder(
-                "pub fn foo(mut _env: EOEnv<'_>) -> i32 {",
+                "use eo_env::eo_enum::EO;",
+                "use eo_env::eo_enum::EO::{EOInt};",
+                "pub fn foo(_env: &EOEnv) -> EO {",
                 "println!(\"{}\", x);"
             )
         );
         MatcherAssert.assertThat(
             new TextOf(res.get(two)).asString(),
             Matchers.stringContainsInOrder(
-                "pub fn foo(mut _env: EOEnv<'_>) -> i32 {",
+                "use eo_env::eo_enum::EO;",
+                "use eo_env::eo_enum::EO::{EOInt};",
+                "pub fn foo(_env: &EOEnv) -> EO {",
                 "print!(\"Hello 大 2\");"
             )
         );
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
index b24d990909..305dc3cd05 100644
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
+++ b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/simple-rust.eo
@@ -6,12 +6,14 @@
     """
     use rand::Rng;
     use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
 
-    pub fn foo(mut env: EOEnv<'_>) -> EO {
+    pub fn foo(_env: &EOEnv) -> EO {
       let mut rng = rand::thread_rng();
       print!("Hello world");
-      let i = rng.gen::<i32>();
-      i
+      let i = rng.gen::<i64>();
+      EOInt(i)
     }
     """
     *
diff --git a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
index 5f3af4f5d1..35528a1a6b 100644
--- a/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
+++ b/eo-maven-plugin/src/test/resources/org/eolang/maven/binarize/twice-rust.eo
@@ -5,8 +5,10 @@
   QQ.rust > r
     """
     use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
 
-    pub fn foo(mut _env: EOEnv<'_>) -> EO {
+    pub fn foo(_env: &EOEnv) -> EO {
       let x = rand::random::<i32>();
       println!("{}", x);
       EOInt(x as i64)
@@ -20,8 +22,10 @@
   QQ.rust > r
     """
     use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
 
-    pub fn foo(mut _env: EOEnv<'_>) -> EO {
+    pub fn foo(_env: &EOEnv) -> EO {
       print!("Hello 大 2");
       let x = rand::random::<i32>();
       EOInt(x as i64)

From ad6d2ae7b9138c686a8bc86dd31d29650dbeb541 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 01:51:47 +0300
Subject: [PATCH 05/16] #2283: unused import

---
 .../src/test/java/org/eolang/maven/BinarizeMojoTest.java         | 1 -
 1 file changed, 1 deletion(-)

diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
index f0234ad5dc..0581a9beb6 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeMojoTest.java
@@ -23,7 +23,6 @@
  */
 package org.eolang.maven;
 
-import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.nio.file.Paths;

From c406fc8951710ef6add06abb7b5db24d16b50f03 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 01:56:08 +0300
Subject: [PATCH 06/16] #2283: restored to master

---
 eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java b/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
index be471f8bac..00cb9980ae 100644
--- a/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
+++ b/eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java
@@ -54,7 +54,7 @@
 final class SyntaxTest {
 
     @Test
-    void EOFloatpleCode() throws Exception {
+    void parsesSimpleCode() throws Exception {
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         final Syntax syntax = new Syntax(
             "test-1",

From c9aa20624f27a81cf59cca02fa4c96f4758cbb02 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 02:12:30 +0300
Subject: [PATCH 07/16] #2283: removed unused import

---
 .../src/test/java/org/eolang/maven/BinarizeParseMojoTest.java    | 1 -
 1 file changed, 1 deletion(-)

diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
index 883955d7ce..572aff8429 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/BinarizeParseMojoTest.java
@@ -24,7 +24,6 @@
 package org.eolang.maven;
 
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Map;
 import org.cactoos.text.TextOf;
 import org.eolang.jucs.ClasspathSource;

From cd9818b3dc4ff50b2bb5e10f9f98de8344ce353f Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 02:13:18 +0300
Subject: [PATCH 08/16] #2283: Updated to new signature of rust inserts

---
 .../src/test/java/org/eolang/maven/rust/NativeTest.java         | 2 +-
 .../src/test/java/org/eolang/maven/rust/PrimeModuleTest.java    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/rust/NativeTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/rust/NativeTest.java
index c451847d44..771ddd2e37 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/rust/NativeTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/rust/NativeTest.java
@@ -52,7 +52,7 @@ void savesCorrectly(@TempDir final Path temp) throws Exception {
                 "package mypackage;",
                 "import EOorg.EOeolang.EOrust;",
                 "public class name {",
-                "    public static native int name",
+                "    public static native byte[] name",
                 "        (final EOrust eo);",
                 "}"
                 )
diff --git a/eo-maven-plugin/src/test/java/org/eolang/maven/rust/PrimeModuleTest.java b/eo-maven-plugin/src/test/java/org/eolang/maven/rust/PrimeModuleTest.java
index 8a39b1134b..9355f12673 100644
--- a/eo-maven-plugin/src/test/java/org/eolang/maven/rust/PrimeModuleTest.java
+++ b/eo-maven-plugin/src/test/java/org/eolang/maven/rust/PrimeModuleTest.java
@@ -49,7 +49,7 @@ void savesCorrectly(@TempDir final Path temp) throws Exception {
             ).asString(),
             Matchers.stringContainsInOrder(
                 String.format("Java_EOrust_natives_%s_%s", method, method),
-                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> jint"
+                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> JByteArray"
             )
         );
     }

From a373e998856c8f6f7f27a98c4c23bbca329baac3 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 02:31:56 +0300
Subject: [PATCH 09/16] #2283: Added todo

---
 .../src/main/java/EOorg/EOeolang/EOrust.java  | 34 +++++++++++++------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index aa82c45e83..7dd74dd962 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -130,9 +130,10 @@ public EOrust(final Phi sigma) {
                             "EOrust.natives.%s",
                             name
                         )
-                    ).getDeclaredMethod(name, new Class[]{EOrust.class});
-                    byte[] res = (byte[]) method.invoke(null, this);
-                    return EOrust.translate(res);
+                    ).getDeclaredMethod(name, EOrust.class);
+                    return EOrust.translate(
+                        (byte[]) method.invoke(null, this)
+                    );
                 }
             )
         );
@@ -230,6 +231,17 @@ private static ConcurrentHashMap<String, String> load(final String src) throws I
         }
     }
 
+    /**
+     * Translates byte message from rust side to Phi object.
+     * @param message Message that native method returns.
+     * @return Phi object.
+     * @todo #2283:45min Implement handling of vertex returning.
+     *  It must convert message array from 1 to last byte to the int
+     *  and return eo object with corresponding vertex then.
+     * @todo #2283:45min Implement handling of String returning.
+     *  It must convert message array from 1 to last byte to the String
+     *  and return eo object with converted String Data.
+     */
     private static Phi translate(final byte[] message) {
         final byte determinant = message[0];
         final byte[] content = Arrays.copyOfRange(message, 1, message.length);
@@ -240,16 +252,16 @@ private static Phi translate(final byte[] message) {
                     "Returning vertex is not implemented yet"
                 );
             case 1:
-                ByteBuffer byteBuffer = ByteBuffer.allocate(Double.BYTES);
-                byteBuffer.put(content);
-                byteBuffer.flip();
-                ret = new Data.ToPhi(byteBuffer.getDouble());
+                ByteBuffer buffer = ByteBuffer.allocate(Double.BYTES);
+                buffer.put(content);
+                buffer.flip();
+                ret = new Data.ToPhi(buffer.getDouble());
                 break;
             case 2:
-                byteBuffer = ByteBuffer.allocate(Long.BYTES);
-                byteBuffer.put(content);
-                byteBuffer.flip();
-                ret = new Data.ToPhi(byteBuffer.getLong());
+                buffer = ByteBuffer.allocate(Long.BYTES);
+                buffer.put(content);
+                buffer.flip();
+                ret = new Data.ToPhi(buffer.getLong());
                 break;
             default:
                 throw new ExFailure(

From aa516d4f17ba8b51e3beed724ae9fa49320418b4 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 02:32:18 +0300
Subject: [PATCH 10/16] #2283: marked unused field

---
 eo-runtime/src/main/rust/eo_env/src/eo_env.rs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/eo-runtime/src/main/rust/eo_env/src/eo_env.rs b/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
index 4057454f2f..3c6793a980 100644
--- a/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
+++ b/eo-runtime/src/main/rust/eo_env/src/eo_env.rs
@@ -26,18 +26,17 @@ pub mod eo_enum;
 use jni::JNIEnv;
 use jni::objects::{JClass, JObject, JValue};
 
-#[allow(dead_code)]
 pub struct EOEnv<'local> {
     pub java_env: JNIEnv<'local>,
-    java_class: JClass<'local>,
+    _java_class: JClass<'local>,
     java_obj: JObject<'local>
 }
 
 impl<'local> EOEnv<'_> {
-    pub fn new(java_env: JNIEnv<'local>, java_class: JClass<'local>, java_obj: JObject<'local>) -> EOEnv<'local> {
+    pub fn new(java_env: JNIEnv<'local>, _java_class: JClass<'local>, java_obj: JObject<'local>) -> EOEnv<'local> {
         EOEnv {
             java_env,
-            java_class,
+            _java_class,
             java_obj
         }
     }

From b661c499ef790d01ee23d174221b4f840f61ac14 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 15:05:28 +0300
Subject: [PATCH 11/16] #2283: Added tests to check translating correctness.

---
 .../src/test/eo/org/eolang/rust-tests.eo      | 51 +++++++++++++++----
 1 file changed, 41 insertions(+), 10 deletions(-)

diff --git a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
index 66717b0df4..469990bfd0 100644
--- a/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
+++ b/eo-runtime/src/test/eo/org/eolang/rust-tests.eo
@@ -26,7 +26,7 @@
 +package org.eolang
 +version 0.0.0
 
-[] > rust-returns-int
+[] > rust-returns-positive-int
   QQ.rust > r
     """
     use eo_env::EOEnv;
@@ -35,8 +35,7 @@
 
     pub fn foo(_env: &mut EOEnv) -> EO {
       println!("Hello world from rust");
-      let x = 4.0_f32;
-      EOInt(x.sqrt() as i64)
+      EOInt(2)
     }
     """
     *
@@ -45,7 +44,25 @@
     $.equal-to
       2
 
-[] > rust-returns-doable
+[] > rust-returns-negative-int
+  QQ.rust > r
+    """
+    use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOInt};
+
+    pub fn foo(_env: &mut EOEnv) -> EO {
+      println!("Hello world from rust");
+      EOInt(-10)
+    }
+    """
+    *
+  assert-that > @
+    r
+    $.equal-to
+      -10
+
+[] > rust-returns-positive-doable
   QQ.rust > r
     """
     use eo_env::EOEnv;
@@ -53,16 +70,31 @@
     use eo_env::eo_enum::EO::{EOFloat};
 
     pub fn foo(_env: &mut EOEnv) -> EO {
-      println!("Hello world from EOFloat");
-      let x = 4.0_f64;
-      EOFloat(x.sqrt())
+      EOFloat(1.23456789)
     }
     """
     *
   assert-that > @
     r
     $.equal-to
-      2.0
+      1.23456789
+
+[] > rust-returns-negative-doable
+  QQ.rust > r
+    """
+    use eo_env::EOEnv;
+    use eo_env::eo_enum::EO;
+    use eo_env::eo_enum::EO::{EOFloat};
+
+    pub fn foo(_env: &mut EOEnv) -> EO {
+      EOFloat(-1.23456789)
+    }
+    """
+    *
+  assert-that > @
+    r
+    $.equal-to
+      -1.23456789
 
 [] > rust-find-returns-int
   QQ.rust > r
@@ -72,8 +104,7 @@
     use eo_env::eo_enum::EO::{EOInt};
 
     pub fn foo(env: &mut EOEnv) -> EO {
-      env.find("^");
-      EOInt(0 as i64)
+      EOInt(env.find("^").into())
     }
     """
     *

From 91c34694b657af49b375e7a92bab940db22d488d Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 15:06:10 +0300
Subject: [PATCH 12/16] #2283: Added @todo about Universe implementation

---
 eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index 7dd74dd962..619fbed60b 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -58,6 +58,10 @@
  * @checkstyle MethodNameCheck (100 lines)
  * @checkstyle LineLengthCheck (100 lines)
  * @checkstyle TypeNameCheck (5 lines)
+ * @todo #2283: 90min Create Universe class. now its functionality is
+ *  assigned to "EORust", which is why it is overcomplicated. "Universe"
+ *  should perform a model of interaction with "eo" objects through
+ *  methods "find", "put", "copy", "dataize" and "bind".
  */
 @XmirObject(oname = "rust")
 public class EOrust extends PhDefault {

From c43aabd8aed68ba398b4354c093e9685308463a0 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 15:31:12 +0300
Subject: [PATCH 13/16] #2283: Added lifetime parameter

---
 .../src/main/java/org/eolang/maven/rust/PrimeModule.java        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
index 156c94ba76..63a566547b 100644
--- a/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
+++ b/eo-maven-plugin/src/main/java/org/eolang/maven/rust/PrimeModule.java
@@ -47,7 +47,7 @@ public PrimeModule(final String method, final String file) {
                 "#[no_mangle]",
                 "pub extern \"system\" fn",
                 String.format("Java_EOrust_natives_%s_%s", method, method),
-                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> JByteArray",
+                "<'local> (env: JNIEnv<'local>, _class: JClass<'local>, universe: JObject<'local>) -> JByteArray<'local>",
                 "{ let mut eo_env = EOEnv::new(env, _class, universe); ",
                 "let arr = foo(&mut eo_env).eo2vec();",
                 "eo_env.java_env.byte_array_from_slice(&arr.as_slice()).unwrap() }"

From ed11b7a634e78f24bdc8d47054dd2173a4f0e058 Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Sun, 23 Jul 2023 15:31:26 +0300
Subject: [PATCH 14/16] #2283: Edited todo description

---
 eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index 619fbed60b..8da34c372c 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -58,7 +58,7 @@
  * @checkstyle MethodNameCheck (100 lines)
  * @checkstyle LineLengthCheck (100 lines)
  * @checkstyle TypeNameCheck (5 lines)
- * @todo #2283: 90min Create Universe class. now its functionality is
+ * @todo #2283:90min Create Universe class. now its functionality is
  *  assigned to "EORust", which is why it is overcomplicated. "Universe"
  *  should perform a model of interaction with "eo" objects through
  *  methods "find", "put", "copy", "dataize" and "bind".

From 869893aedf218ed5709a9f8e2ea78343a54f1aea Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Mon, 24 Jul 2023 12:19:21 +0300
Subject: [PATCH 15/16] #2283: typo in todo description

---
 eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index 8da34c372c..e89b83d37b 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -58,7 +58,7 @@
  * @checkstyle MethodNameCheck (100 lines)
  * @checkstyle LineLengthCheck (100 lines)
  * @checkstyle TypeNameCheck (5 lines)
- * @todo #2283:90min Create Universe class. now its functionality is
+ * @todo #2283:90min Create Universe class. Now its functionality is
  *  assigned to "EORust", which is why it is overcomplicated. "Universe"
  *  should perform a model of interaction with "eo" objects through
  *  methods "find", "put", "copy", "dataize" and "bind".

From 89612a4601af7c1f25bf252b936d26f330e738dc Mon Sep 17 00:00:00 2001
From: levBagryansky <28lev11@gmail.com>
Date: Mon, 24 Jul 2023 12:51:49 +0300
Subject: [PATCH 16/16] #2283: Added return type validating

---
 eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
index e89b83d37b..66ad9fd061 100644
--- a/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
+++ b/eo-runtime/src/main/java/EOorg/EOeolang/EOrust.java
@@ -135,6 +135,14 @@ public EOrust(final Phi sigma) {
                             name
                         )
                     ).getDeclaredMethod(name, EOrust.class);
+                    if (method.getReturnType() != byte[].class) {
+                        throw new ExFailure(
+                            "Return type of %s is %s, required %s",
+                            method,
+                            method.getReturnType(),
+                            byte[].class
+                        );
+                    }
                     return EOrust.translate(
                         (byte[]) method.invoke(null, this)
                     );