Enable disposing environment when code execution is done

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

@@ -19,6 +19,7 @@ interface Environment {
    fun printScopes()
    fun setVariable(name: String, value: Value)
    fun getVariable(name: String): Value
+   fun dispose()
 
    fun getRootModule(): Module
 }

api/src/main/kotlin/io/smnp/ext/ModuleProvider.kt

@@ -7,6 +7,7 @@ import org.pf4j.ExtensionPoint
 
 abstract class ModuleProvider(val path: String) : ExtensionPoint {
     open fun onModuleLoad(environment: Environment) {}
+    open fun beforeModuleDisposal(environment: Environment) {}
     open fun dependencies(): List<String> = emptyList()
     abstract fun provideModule(interpreter: Interpreter): Module
 }

api/src/main/kotlin/io/smnp/ext/ModuleRegistry.kt

@@ -1,6 +1,9 @@
 package io.smnp.ext
 
+import io.smnp.environment.Environment
+
 interface ModuleRegistry {
     fun requestModuleProviderForPath(path: String): ModuleProvider?
     fun registeredModules(): List<String>
+    fun disposeModules(environment: Environment)
 }

api/src/main/kotlin/io/smnp/runtime/model/CallStack.kt

@@ -18,6 +18,9 @@ class CallStack {
 
     fun top() = items.top()
 
+    val size: Int
+    get() = items.size
+
     fun pretty() {
         items.asReversed().forEachIndexed { index, item -> println("[${items.size - index - 1}] $item") }
     }

api/src/main/kotlin/io/smnp/runtime/model/CallStackFrame.kt

@@ -19,6 +19,9 @@ data class CallStackFrame(
 
     fun popScope() = scopes.pop()
 
+    val scopesCount: Int
+    get() = scopes.size
+
     fun setVariable(name: String, value: Value) {
         val scope = scopes.lastOrNull { it.containsKey(name) } ?: scopes.top()
         scope[name] = value