Merge pull request #539 from dictu-lang/feature/object_from

Object.createFrom()

docs/docs/standard-lib/object.md

@@ -0,0 +1,53 @@
+---
+layout: default
+title: Object
+nav_order: 17
+parent: Standard Library
+---
+
+# Object
+{: .no_toc }
+
+## Table of contents
+{: .no_toc .text-delta }
+
+1. TOC
+{:toc}
+
+---
+
+## Object
+
+To make use of the Object module an import is required.
+
+```cs
+import Object;
+```
+
+### Object.getClassRef(string)
+
+This method will attempt to get a class reference from the class name provided as a string.
+
+Returns a Result and unwraps to an Object upon success.
+
+**NOTE:** This currently only works if the class is defined in the global scope
+
+```cs
+class Test {}
+
+Object.getClassRef("Test").unwrap(); // <Cls Test>
+```
+
+### Object.createFrom(string)
+
+This method will attempt to create a new object from the class name provided as a string.
+
+Returns a Result and unwraps to an Object upon success.
+
+**NOTE:** This currently only works if the class is defined in the global scope
+
+```cs
+class Test {}
+
+Object.createFrom("Test").unwrap(); // <Test instance>
+```

scripts/generate.du

@@ -31,7 +31,8 @@ var files = [
     'src/vm/datatypes/result/result',
     'src/optionals/unittest/unittest',
     'src/optionals/env/env',
-    'src/optionals/http/http'
+    'src/optionals/http/http',
+    'src/optionals/object/object'
 ];
 
 for (var i = 0; i < files.len(); i += 1) {

src/optionals/object/object-source.h

@@ -0,0 +1,9 @@
+#define DICTU_OBJECT_SOURCE "import Object;\n" \
+"\n" \
+"def createFrom(className, ...arguments) {\n" \
+"    return Object.__getClassRef(className).matchWrap(\n" \
+"        def (klass) => klass(...arguments),\n" \
+"        def (error) => error\n" \
+"    );\n" \
+"}\n" \
+

src/optionals/object/object.c

@@ -0,0 +1,69 @@
+#include "object.h"
+
+#include "object-source.h"
+
+static Value objectGetClassRefImpl(DictuVM *vm, int argCount, Value *args, bool internal) {
+    if (argCount != 1) {
+        runtimeError(vm, "getClassRef() takes 1 argument (%d given)", argCount);
+        return EMPTY_VAL;
+    }
+
+    if (!IS_STRING(args[0])) {
+        runtimeError(vm, "getClassRef() argument must be a string");
+        return EMPTY_VAL;
+    }
+
+    ObjString *classString = AS_STRING(args[0]);
+
+    Value klass;
+    CallFrame *frame;
+    if (internal) {
+        // -2 as we want to go to the callee site, not the Object.du code
+        frame = &vm->frames[vm->frameCount - 2];
+    } else {
+        frame = &vm->frames[vm->frameCount - 1];
+    }
+
+    if (tableGet(&frame->closure->function->module->values, classString, &klass) && IS_CLASS(klass)) {
+        return newResultSuccess(vm, klass);
+    }
+
+    char *error = ALLOCATE(vm, char, classString->length + 26);
+    memcpy(error, classString->chars, classString->length);
+    memcpy(error + classString->length, " class could not be found", 25);
+    error[classString->length + 25] = '\0';
+
+    Value result = newResultError(vm, error);
+
+    FREE_ARRAY(vm, char, error, classString->length + 26);
+
+    return result;
+}
+
+static Value objectGetClassRef(DictuVM *vm, int argCount, Value *args) {
+    return objectGetClassRefImpl(vm, argCount, args, false);
+}
+
+static Value objectGetClassRefInternal(DictuVM *vm, int argCount, Value *args) {
+    return objectGetClassRefImpl(vm, argCount, args, true);
+}
+
+Value createObjectModule(DictuVM *vm) {
+    ObjClosure *closure = compileModuleToClosure(vm, "Object", DICTU_OBJECT_SOURCE);
+
+    if (closure == NULL) {
+        return EMPTY_VAL;
+    }
+
+    push(vm, OBJ_VAL(closure));
+
+    /**
+     * Define Object methods
+     */
+    defineNative(vm, &closure->function->module->values, "__getClassRef", objectGetClassRefInternal);
+    defineNative(vm, &closure->function->module->values, "getClassRef", objectGetClassRef);
+
+    pop(vm);
+
+    return OBJ_VAL(closure);
+}

src/optionals/object/object.du

@@ -0,0 +1,8 @@
+import Object;
+
+def createFrom(className, ...arguments) {
+    return Object.__getClassRef(className).matchWrap(
+        def (klass) => klass(...arguments),
+        def (error) => error
+    );
+}

src/optionals/object/object.h

@@ -0,0 +1,11 @@
+#ifndef dictu_object_module_h
+#define dictu_object_module_h
+
+#include <stdlib.h>
+
+#include "../optionals.h"
+#include "../../vm/vm.h"
+
+Value createObjectModule(DictuVM *vm);
+
+#endif //dictu_object_module_h

src/optionals/optionals.c

@@ -16,6 +16,7 @@ BuiltinModules modules[] = {
         {"System", &createSystemModule, false},
         {"UnitTest", &createUnitTestModule, true},
         {"Inspect", &createInspectModule, false},
+        {"Object", &createObjectModule, true},
 #ifndef DISABLE_HTTP
         {"HTTP", &createHTTPModule, true},
 #endif

src/optionals/optionals.h

@@ -18,6 +18,7 @@
 #include "sqlite.h"
 #include "process.h"
 #include "inspect.h"
+#include "object/object.h"
 #include "unittest/unittest.h"
 
 typedef Value (*BuiltinModule)(DictuVM *vm);

tests/object/createFrom.du

@@ -0,0 +1,21 @@
+/**
+ * createFrom.du
+ *
+ * Testing the Object.createFrom method
+ */
+from UnitTest import UnitTest;
+
+import Object;
+
+class Test {}
+
+class TestObjectCreateFrom < UnitTest {
+    testObjectCreateFrom() {
+        this.assertSuccess(Object.createFrom('Test'));
+        this.assertError(Object.createFrom('Unknown'));
+
+        this.assertType(Object.createFrom('Test').unwrap(), 'Test');
+    }
+}
+
+TestObjectCreateFrom().run();

tests/object/import.du

@@ -0,0 +1,7 @@
+/**
+ * import.du
+ *
+ * General import file for all the Object module tests
+ */
+
+import "createFrom.du";

tests/runTests.du

@@ -40,6 +40,7 @@ import "modules/import.du";
 import "imports/import.du";
 import "random/import.du";
 import "hashlib/import.du";
+import "object/import.du";
 
 // If we got here no runtime errors were thrown, therefore all tests passed.
 print("All tests passed successfully!");