Add support for function/methods invocation on Environment + create call stack model

app/src/main/kotlin/io/smnp/environment/DefaultEnvironment.kt

@@ -1,11 +1,19 @@
 package io.smnp.environment
 
+import io.smnp.callable.signature.ActualSignatureFormatter.format
 import io.smnp.ext.DefaultModuleRegistry
+import io.smnp.runtime.model.CallStack
+import io.smnp.type.model.Value
 import io.smnp.type.module.Module
 
 class DefaultEnvironment : Environment {
     private val rootModule = Module("<root>")
     private val loadedModules = mutableListOf<String>()
+    private val callStack = CallStack()
+
+    init {
+        callStack.push(rootModule, "<entrypoint>", emptyList())
+    }
 
     override fun loadModule(path: String) {
         DefaultModuleRegistry.requestModulesForPath(path).forEach {
@@ -17,4 +25,46 @@ class DefaultEnvironment : Environment {
     override fun printModules(printContent: Boolean) {
         rootModule.pretty(printContent)
     }
+
+    override fun invokeFunction(name: String, arguments: List<Value>): Value {
+        val foundFunctions = rootModule.findFunction(name)
+        if(foundFunctions.isEmpty()) {
+            throw RuntimeException("No function found with name of '$name'")
+        }
+
+        if(foundFunctions.size > 1) {
+            throw RuntimeException("Found ${foundFunctions.size} functions with name of $foundFunctions")
+        }
+
+        val function = foundFunctions[0]
+
+        callStack.push(function.module, function.name, arguments)
+        val value = function.call(this, *arguments.toTypedArray())
+        callStack.pop()
+
+        return value
+    }
+
+    override fun invokeMethod(obj: Value, name: String, arguments: List<Value>): Value {
+        val foundMethods = rootModule.findMethod(obj, name)
+        if(foundMethods.isEmpty()) {
+            throw RuntimeException("No method found with name of '$name' for ${format(obj)}")
+        }
+
+        if(foundMethods.size > 1) {
+            throw RuntimeException("Found ${foundMethods.size} methods with name of '$foundMethods' for ${format(obj)}")
+        }
+
+        val method = foundMethods[0]
+
+        callStack.push(method.module, "${method.typeMatcher}.${method.name}", arguments)
+        val value = method.call(this, obj, *arguments.toTypedArray())
+        callStack.pop()
+
+        return value
+    }
+
+    override fun printCallStack() {
+        callStack.pretty()
+    }
 }