naive codegen implementation

library/gen/build.gradle.kts

@@ -0,0 +1,3 @@
+dependencies {
+    implementation("net.bytebuddy:byte-buddy:1.14.17")
+}

library/gen/src/main/java/dev/frogmc/froglib/gen/api/AbstractCodegenBuilder.java

@@ -0,0 +1,66 @@
+package dev.frogmc.froglib.gen.api;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.dynamic.DynamicType;
+import net.bytebuddy.implementation.MethodCall;
+import net.bytebuddy.matcher.ElementMatchers;
+import net.minecraft.world.level.block.Block;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.ParameterizedType;
+import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.function.Function;
+
+/**
+ * {@code AbstractCodegenBuilder} is a template for creating Builder patterned classes that create anonymous, dynamic classes.
+ * @param <T> The superclass of the classes that will be generated.
+ */
+public abstract class AbstractCodegenBuilder<T> {
+    /**
+     * Represents the class builder.
+     */
+    protected DynamicType.Builder<?> dt;
+    /**
+     * Represents the arguments that will be provided to the dynamic classes constructor.
+     */
+    protected Object[] args; // TODO this seems bad?
+    /**
+     * Represents the fields that this dynamic class will contain.
+     */
+    protected Map<String, Object> fields; // TODO this is really bad, probably just figure out how to actually properly add fields
+
+    /**
+     * Constructs a new AbstractCodegenBuilder. Subclasses should provide their own public constructor.
+     */
+    protected AbstractCodegenBuilder() {
+        this.dt = new ByteBuddy()
+                .subclass((Class<T>) ((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[0]);
+    }
+
+    /**
+     * Overrides a method of the superclass in the dynamically-generated class.
+     * @param method The signature of the method to override.
+     * @param body A {@link FunctionalInterface} representing the body of the new overridden method.
+     */
+    protected void overrideMethod(String method, Callable<?> body) throws NoSuchMethodException { // TODO handle instead of throwing
+        this.dt = this.dt.method(ElementMatchers.anyOf(((Class<T>) ((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[0]).getDeclaredMethod(method))) // FIXME i literally have no idea if this works lmao
+                .intercept(MethodCall.call(body));
+    }
+
+    /**
+     * Creates the dynamic class as well as a singleton instance of it. Subclasses should provide their own public {@code build} method.
+     * @return The singleton instance of the dynamic class.
+     */
+    protected T build() throws InstantiationException, IllegalAccessException, NoSuchMethodException, InvocationTargetException { // TODO handle instead of throwing
+        if(this.fields.containsValue(null)) {
+            throw new IllegalAccessException();
+        }
+        return (T) this.dt
+                .make()
+                .load(getClass().getClassLoader())
+                .getLoaded() // TODO we might want to return this instead?
+                .getDeclaredConstructor()
+                .newInstance(this.args);
+    }
+}

library/gen/src/main/resources/frog.mod.toml

@@ -0,0 +1,22 @@
+[frog]
+format_version = "1.0.0"
+
+[frog.mod]
+id = "froglib_gen"
+name = "FrogLib Data and Code Generation"
+version = "$version"
+license = "Apache-2.0"
+credits = [
+    { name = "FrogMC Team", roles = ["author"] }
+]
+
+[frog.dependencies]
+depends = [
+    { id = "minecraft", versions = "~$game_version", name = "Minecraft" }
+]
+
+[frog.extensions]
+prelaunch = "net.frogmc.froglib.gen.impl.FrogGenPrelaunch"
+mixin = [
+    "froglib.gen.mixins.json"
+]

library/gen/src/main/resources/froglib.gen.mixins.json

@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "dev.frogmc.froglib.gen.impl.mixin",
+	"compatibilityLevel": "JAVA_21",
+	"mixins": [
+	],
+	"server": [
+	],
+	"client": [
+
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}

settings.gradle.kts

@@ -27,3 +27,5 @@ include("library:registries")
 findProject(":library:registries")?.name = "registries"
 include("library:player")
 findProject(":library:player")?.name = "player"
+include("library:gen")
+findProject(":library:gen")?.name = "gen"