Create scaffolding for custom functions

api/src/main/kotlin/io/smnp/callable/function/Function.kt

@@ -30,7 +30,7 @@ abstract class Function(val name: String) {
             .firstOrNull { (_, args) -> args.signatureMatched }
             ?: throw FunctionInvocationException(this, arguments)
 
-        return definition.body(environment, arguments.toList())
+        return definition.body(environment, args.arguments)
     }
 
     val signature: String

api/src/main/kotlin/io/smnp/data/entity/Note.kt

@@ -2,7 +2,7 @@ package io.smnp.data.entity
 
 import io.smnp.data.enumeration.Pitch
 
-class Note private constructor(val pitch: Pitch, val octave: Int, val duration: Int, val dot: Boolean) {
+data class Note (val pitch: Pitch, val octave: Int, val duration: Int, val dot: Boolean) {
     data class Builder(var pitch: Pitch = Pitch.A, var octave: Int = 4, var duration: Int = 4, var dot: Boolean = false) {
         fun pitch(pitch: Pitch) = apply { this.pitch = pitch }
         fun octave(octave: Int) = apply { this.octave = octave }

api/src/main/kotlin/io/smnp/environment/Environment.kt

@@ -1,5 +1,7 @@
 package io.smnp.environment
 
+import io.smnp.callable.function.Function
+import io.smnp.callable.method.Method
 import io.smnp.type.model.Value
 
 interface Environment {
@@ -8,4 +10,6 @@ interface Environment {
     fun invokeFunction(name: String, arguments: List<Value>): Value
     fun invokeMethod(obj: Value, name: String, arguments: List<Value>): Value
     fun printCallStack()
+    fun defineFunction(function: Function)
+    fun defineMethod(method: Method)
 }

api/src/main/kotlin/io/smnp/type/module/Module.kt

@@ -32,8 +32,14 @@ class Module(
         }
     }
 
-    fun attachTo(module: Module) {
-        module.addSubmodule(this)
+    fun addFunction(function: Function) {
+        function.module = this
+        functions.add(function)
+    }
+
+    fun addMethod(method: Method) {
+        method.module = this
+        methods.add(method)
     }
 
     val canonicalName: String