Support LuaTable arguments in @LuaFunction

Author: SquidDev

projects/core-api/src/main/java/dan200/computercraft/api/lua/ObjectLuaTable.java

@@ -61,4 +61,14 @@ public Collection<Object> values() {
     public Set<Entry<Object, Object>> entrySet() {
         return map.entrySet();
     }
+
+    @Override
+    public boolean equals(Object o) {
+        return this == o || o instanceof Map<?, ?> otherMap && map.equals(otherMap);
+    }
+
+    @Override
+    public int hashCode() {
+        return map.hashCode();
+    }
 }

projects/core/src/main/java/dan200/computercraft/core/asm/Generator.java

@@ -73,6 +73,22 @@ static void addArgType(Map<Class<?>, ArgMethods> types, Class<?> type, String na
             addArgType(argMethodMap, Map.class, "Table");
             addArgType(argMethodMap, String.class, "String");
             addArgType(argMethodMap, ByteBuffer.class, "Bytes");
+            argMethodMap.put(LuaTable.class, new ArgMethods(
+                // i -> new ObjectLuaTable(getTable(i))
+                MethodHandles.filterReturnValue(
+                    LOOKUP.findVirtual(IArguments.class, "getTable", MethodType.methodType(Map.class, int.class)),
+                    LOOKUP.findConstructor(ObjectLuaTable.class, MethodType.methodType(void.class, Map.class))
+                        .asType(MethodType.methodType(LuaTable.class, Map.class))
+                ),
+                // i -> optTable(i).map(ObjectLuaTable::new)
+                MethodHandles.filterReturnValue(
+                    LOOKUP.findVirtual(IArguments.class, "optTable", MethodType.methodType(Optional.class, int.class)),
+                    MethodHandles.insertArguments(
+                        LOOKUP.findVirtual(Optional.class, "map", MethodType.methodType(Optional.class, Function.class)),
+                        1, (Function<Map<?, ?>, LuaTable<?, ?>>) ObjectLuaTable::new
+                    )
+                )
+            ));
             argMethods = Map.copyOf(argMethodMap);
 
             ARG_TABLE_UNSAFE = ArgMethods.of(LuaTable.class, "TableUnsafe");
@@ -335,10 +351,9 @@ private static MethodHandle setReturn(MethodHandle handle, Class<?> retTy) {
     }
 
     private static @Nullable ArgMethods getArgMethods(Class<?> type, boolean unsafe) {
-        var getter = argMethods.get(type);
-        if (getter != null) return getter;
         if (type == LuaTable.class && unsafe) return ARG_TABLE_UNSAFE;
-        return null;
+
+        return argMethods.get(type);
     }
 
     /**

projects/core/src/test/java/dan200/computercraft/core/asm/GeneratorTest.java

@@ -10,6 +10,7 @@
 import dan200.computercraft.core.methods.LuaMethod;
 import dan200.computercraft.core.methods.NamedMethod;
 import org.hamcrest.Matcher;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
@@ -123,6 +124,17 @@ public void testEnum() throws LuaException {
         assertThrows(LuaException.class, () -> apply(methods, new EnumMethods(), "getEnum", "not as side"));
     }
 
+    @Test
+    public void testLuaTable() throws LuaException {
+        var methods = GENERATOR.getMethods(TableMethods.class);
+        assertThat(methods, containsInAnyOrder(named("getTable"), named("optTable")));
+
+        assertThat(apply(methods, new TableMethods(), "getTable", Map.of("x", "y")), one(is(Map.of("x", "y"))));
+        assertThat(apply(methods, new TableMethods(), "optTable", Map.of("x", "y")), one(is(Map.of("x", "y"))));
+        assertThat(apply(methods, new TableMethods(), "optTable"), one(nullValue()));
+        assertThrows(LuaException.class, () -> apply(methods, new TableMethods(), "getTable", "not a table"));
+    }
+
     @Test
     public void testMainThread() throws LuaException {
         var methods = GENERATOR.getMethods(MainThread.class);
@@ -277,6 +289,18 @@ public final String optEnum(Optional<ComputerSide> side) {
         }
     }
 
+    public static class TableMethods {
+        @LuaFunction
+        public final LuaTable<?, ?> getTable(LuaTable<?, ?> table) {
+            return table;
+        }
+
+        @LuaFunction
+        public final @Nullable LuaTable<?, ?> optTable(Optional<LuaTable<?, ?>> table) {
+            return table.orElse(null);
+        }
+    }
+
     public static class MainThread {
         @LuaFunction(mainThread = true)
         public final void go() {
@@ -288,10 +312,6 @@ public static class Unsafe {
         public final void withUnsafe(LuaTable<?, ?> table) {
         }
 
-        @LuaFunction
-        public final void withoutUnsafe(LuaTable<?, ?> table) {
-        }
-
         @LuaFunction(unsafe = true, mainThread = true)
         public final void invalid(LuaTable<?, ?> table) {
         }