#140 Support creating Java lambdas, export Idris functions as Java classes, constructors, fields and functions

.github/workflows/ci-super-linter.yml

@@ -63,3 +63,4 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           IGNORE_GENERATED_FILES: true
           NATURAL_LANGUAGE_CONFIG_FILE: '.textlintrc.yml'
+          FILTER_REGEX_EXCLUDE: .*Test.java

.github/workflows/install.yml

@@ -12,7 +12,7 @@ on:
 env:
   IDRIS2_TESTS_CG: jvm
   ACTIONS_ALLOW_UNSECURE_COMMANDS: true
-  PREVIOUS_VERSION: 0.6.0
+  PREVIOUS_VERSION: 0.6.0.4
 
 jobs:
   build:

.github/workflows/pre-release.yml

@@ -8,7 +8,7 @@ on:
 env:
   IDRIS2_TESTS_CG: jvm
   ACTIONS_ALLOW_UNSECURE_COMMANDS: true
-  PREVIOUS_VERSION: 0.6.0
+  PREVIOUS_VERSION: 0.6.0.4
 
 jobs:
   pre-release:

.github/workflows/release.yml

@@ -14,7 +14,7 @@ on:
 env:
   IDRIS2_TESTS_CG: jvm
   ACTIONS_ALLOW_UNSECURE_COMMANDS: true
-  PREVIOUS_VERSION: 0.6.0
+  PREVIOUS_VERSION: 0.6.0.4
 
 jobs:
   release:

Makefile

@@ -204,7 +204,7 @@ endif
 	mkdir -p ${PREFIX}/lib/
 	install support/c/${IDRIS2_SUPPORT} ${PREFIX}/lib
 	mkdir -p ${PREFIX}/bin/${NAME}_app
-	install ${TARGETDIR}/${NAME}_app/* ${PREFIX}/bin/${NAME}_app
+	cp -rf ${TARGETDIR}/${NAME}_app ${PREFIX}/bin/
 
 install-support:
 	mkdir -p ${PREFIX}/${NAME_VERSION}/support/docs

docs/ffi/calling-java-from-idris.rst

@@ -63,6 +63,33 @@ Foreign specifier for constructors start with ``<init>`` which is the JVM name f
 Similar to method calls, constructors specify argument types and return type. In this case, we invoke a zero-argument
 constructor returning `java/util/ArrayList`.
 
+Accessing fields
+================
+
+.. code-block:: idris
+
+    data Point : Type where [external]
+
+    -- Get an instance field
+    %foreign "jvm:#x(java/awt/Point int),java/awt/Point"
+    prim_getX : Point -> PrimIO Int
+
+    -- Set an instance field
+    %foreign "jvm:#=x(java/awt/Point int void),java/awt/Point"
+    prim_setX : Point -> Int -> PrimIO ()
+
+    -- Get a static field
+    %foreign "jvm:#MAX_VALUE(int),java/lang/Integer"
+    intMax : Int
+
+    -- Set a static field
+    %foreign "jvm:#=bar(java/lang/String void),io/github/mmhelloworld/helloworld/Main"
+    prim_setBar : String -> PrimIO ()
+
+
+Field foreign specifiers start with ``#``. To mutate fields, foreign specifier starts with ``#=``. Instance field
+accessors will have an additional parameter to pass the instance.
+
 Inheritance
 ===========
 
@@ -133,8 +160,51 @@ Here is a detailed example showing the hierarchy between Java's ``Collection``,
       printLn !(size {elemTy=String} list)
       printLn !(toString list)
 
-Here, we create an `ArrayList` instance and call `get` method from `List` and methods from `Collection` such as
-`add` and `size`. We are able to pass `ArrayList` instance to the `List` and `Collection` functions because of
-`Inherits` interface instances for `ArrayList`. Another note: In JVM, invoking methods on interface is different from
-class methods invocation so the foreign specifiers on interface methods have `i:` prefix for the first parameter that
-represents the instance that the methods are called on.
+Here, we create an ``ArrayList`` instance and call ``get`` method from ``List`` and methods from ``Collection`` such as
+``add`` and ``size``. We are able to pass ``ArrayList`` instance to the ``List`` and ``Collection`` functions because of
+``Inherits`` interface instances for ``ArrayList``. Another note: In JVM, invoking methods on interface is different
+from class methods invocation so the foreign specifiers on interface methods have ``i:`` prefix for the first parameter
+that represents the instance that the methods are called on.
+
+Class literals
+================
+
+``classLiteral`` function can be used to get Java's ``Class`` instances for JVM types.
+
+.. code-block:: console
+
+    Main> :module Java.Lang
+    Imported module Java.Lang
+    Main> :t classLiteral
+    Java.Lang.classLiteral : Class ty
+
+.. code-block:: idris
+
+    import Java.Lang
+
+    main : IO ()
+    main = do
+      printLn !(Object.toString $ classLiteral {ty=Int})
+      printLn !(Object.toString $ classLiteral {ty=Integer})
+      printLn !(Object.toString $ classLiteral {ty=String})
+
+The above example prints:
+
+.. code-block:: console
+
+   "int"
+   "class java.math.BigInteger"
+   "class java.lang.String"
+
+JVM reference equality
+======================
+Reference equality should be avoided in Idris but it might be useful to interface with Java, for example, for overriding ``equals`` method in Idris.
+
+.. code-block:: console
+
+    Main> :module Java.Lang
+    Imported module Java.Lang
+    Main> :exec printLn (jvmRefEq "foo" "foo")
+    True
+    Main> :exec printLn (jvmRefEq "foo" ("fo" ++ "o"))
+    False

idris-jvm-assembler/pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
         <groupId>io.github.mmhelloworld</groupId>
         <artifactId>idris-jvm</artifactId>

idris-jvm-assembler/src/main/java/io/github/mmhelloworld/idrisjvm/assembler/AsmGlobalState.java

@@ -6,17 +6,16 @@
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.file.Paths;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 import java.util.Properties;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -29,7 +28,6 @@
 import static java.nio.file.Files.newInputStream;
 import static java.nio.file.Files.newOutputStream;
 import static java.util.Arrays.asList;
-import static java.util.Collections.emptyList;
 import static java.util.Collections.synchronizedSet;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.stream.Collectors.toList;
@@ -52,18 +50,17 @@ public final class AsmGlobalState {
     private final Set<String> untypedFunctions;
     private final Set<String> constructors;
     private final String programName;
+    private final Map<String, Object> fcAndDefinitionsByName;
     private final Map<String, Assembler> assemblers;
 
-    public AsmGlobalState(String programName, Collection<String> trampolinePatterns) {
+    public <T> AsmGlobalState(String programName,
+                              Map<String, Object> fcAndDefinitionsByName) {
         this.programName = programName;
         functions = new ConcurrentHashMap<>();
         untypedFunctions = synchronizedSet(new HashSet<>());
         constructors = synchronizedSet(new HashSet<>());
         assemblers = new ConcurrentHashMap<>();
-    }
-
-    public AsmGlobalState(String programName) {
-        this(programName, emptyList());
+        this.fcAndDefinitionsByName = fcAndDefinitionsByName;
     }
 
     public static void copyRuntimeJar(String directory) throws IOException {
@@ -80,6 +77,31 @@ public static void copyRuntimeJar(String directory) throws IOException {
         }
     }
 
+    private static List<String> getJavaOptions() {
+        String javaOpts = getProperty("JAVA_OPTS", "-Xss8m");
+        return asList(javaOpts.split("\\s+"));
+    }
+
+    private static String getProperty(String propertyName, String defaultValue) {
+        String value = System.getProperty(propertyName, System.getenv(propertyName));
+        return value == null ? defaultValue : value;
+    }
+
+    private static void copy(InputStream inputStream, OutputStream outputStream) throws IOException {
+        byte[] buffer = new byte[BUFFER_SIZE];
+        while (inputStream.read(buffer) > 0) {
+            outputStream.write(buffer);
+        }
+        outputStream.flush();
+    }
+
+    private static String getRuntimeJarName() throws IOException {
+        ClassLoader classLoader = currentThread().getContextClassLoader();
+        Properties properties = new Properties();
+        properties.load(classLoader.getResourceAsStream("project.properties"));
+        return format("idris-jvm-runtime-%s.jar", properties.getProperty("project.version"));
+    }
+
     public synchronized void addFunction(String name, Object value) {
         functions.put(name, value);
     }
@@ -128,7 +150,6 @@ public void classCodeEnd(String outputDirectory, String outputFile, String mainC
         } else {
             new File(classDirectory).mkdirs();
             copyRuntimeJar(classDirectory);
-            Assembler.createJar(classDirectory, outputFile, mainClassNoSlash);
             Assembler.createExecutable(normalizedOutputDirectory, outputFile, mainClassNoSlash);
         }
     }
@@ -150,41 +171,21 @@ public void interpret(String mainClass, String outputDirectory) throws IOExcepti
     public void writeClass(String className, ClassWriter classWriter, String outputClassFileDir) {
         File outFile = new File(outputClassFileDir, className + ".class");
         new File(outFile.getParent()).mkdirs();
-        try (OutputStream out = new FileOutputStream(outFile)) {
+        try (OutputStream out = newOutputStream(outFile.toPath())) {
             out.write(classWriter.toByteArray());
         } catch (Exception exception) {
             exception.printStackTrace();
         }
     }
 
-    private static List<String> getJavaOptions() {
-        String javaOpts = getProperty("JAVA_OPTS", "-Xss8m");
-        return asList(javaOpts.split("\\s+"));
-    }
-
-    private static String getProperty(String propertyName, String defaultValue) {
-        String value = System.getProperty(propertyName, System.getenv(propertyName));
-        return value == null ? defaultValue : value;
-    }
-
-    private static void copy(InputStream inputStream, OutputStream outputStream) throws IOException {
-        byte[] buffer = new byte[BUFFER_SIZE];
-        while (inputStream.read(buffer) > 0) {
-            outputStream.write(buffer);
-        }
-        outputStream.flush();
-    }
-
-    private static String getRuntimeJarName() throws IOException {
-        ClassLoader classLoader = currentThread().getContextClassLoader();
-        Properties properties = new Properties();
-        properties.load(classLoader.getResourceAsStream("project.properties"));
-        return format("idris-jvm-runtime-%s.jar", properties.getProperty("project.version"));
-    }
-
     private Stream<Entry<String, ClassWriter>> getClassNameAndClassWriters() {
         return assemblers.values().parallelStream()
             .map(Assembler::classInitEnd)
             .flatMap(assembler -> assembler.getClassWriters().entrySet().stream());
     }
+
+    public Object getFcAndDefinition(String name) {
+        return Optional.ofNullable(fcAndDefinitionsByName.get(name))
+            .orElseThrow(() -> new IdrisJvmException("Unable to find function " + name));
+    }
 }