diff --git a/src/commonMain/kotlin/com/infendro/cli/command/Command.kt b/src/commonMain/kotlin/com/infendro/cli/command/Command.kt
index 47dd233..550bf6d 100644
--- a/src/commonMain/kotlin/com/infendro/cli/command/Command.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/command/Command.kt
@@ -95,9 +95,7 @@ class Command private constructor(
     )
 }
 
-fun cli(
-    block: Command.Builder.() -> Unit,
-): Command {
+fun cli(block: Command.Builder.() -> Unit): Command {
     val builder = Command.Builder(-1, null)
     builder.block()
     return builder.build()
diff --git a/src/commonMain/kotlin/com/infendro/cli/command/Execution.kt b/src/commonMain/kotlin/com/infendro/cli/command/Execution.kt
index 65ade04..17a1449 100644
--- a/src/commonMain/kotlin/com/infendro/cli/command/Execution.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/command/Execution.kt
@@ -12,11 +12,7 @@ class Execution private constructor(
     val arguments: List<Arg>,
 ) {
     companion object {
-        fun from(
-            command: Command,
-            cmd: List<String>,
-            arg: List<String>,
-        ): Execution {
+        fun from(command: Command, cmd: List<String>, arg: List<String>): Execution {
             val commands = Cmd.from(cmd)
             val arguments = Arg.from(command, arg)
             return Execution(commands, arguments)
@@ -33,7 +29,7 @@ class Execution private constructor(
 
     class Arg(
         val name: String,
-        val value: String?,
+        val value: Any,
     ) {
         companion object {
             fun from(command: Command, arg: List<String>): List<Arg> = buildList {
@@ -68,10 +64,10 @@ class Execution private constructor(
                     }
 
                     for (name in names) {
-                        if (command.arguments.none { name in it.names })
-                            throw UnknownArgumentException(name)
+                        val argument = command.arguments.firstOrNull { name in it.names }
+                            ?: throw UnknownArgumentException(name)
 
-                        //TODO parse early
+                        val value = argument.parser.parse(value) as Any
                         add(Arg(name, value))
                     }
                     i++
@@ -88,26 +84,11 @@ class Execution private constructor(
         }
     }
 
-    operator fun Command.Key.getValue(
-        thisRef: Any?,
-        property: KProperty<*>,
-    ): String = commands[index].name
+    operator fun Command.Key.getValue(thisRef: Any?, property: KProperty<*>): String = commands[index].name
 
-    operator fun <T> Argument.Single<T>.getValue(
-        thisRef: Any?,
-        property: KProperty<*>,
-    ): T = arguments.single { it.name in names }
-        .let { parser.parse(it.value) }
-
-    operator fun <T> Argument.SingleOrElse<T>.getValue(
-        thisRef: Any?,
-        property: KProperty<*>,
-    ): T = arguments.singleOrNull { it.name in names }
-        ?.let { parser.parse(it.value) } ?: other
-
-    operator fun <T> Argument.SingleOrNull<T>.getValue(
-        thisRef: Any?,
-        property: KProperty<*>,
-    ): T? = arguments.singleOrNull { it.name in names }
-        ?.let { parser.parse(it.value) }
+    @Suppress("UNCHECKED_CAST")
+    private fun <T> Argument<T>.getValue(): T? = arguments.firstOrNull { it.name in names }?.value as? T
+    operator fun <T> Argument.Single<T>.getValue(thisRef: Any?, property: KProperty<*>): T = getValue()!!
+    operator fun <T> Argument.SingleOrElse<T>.getValue(thisRef: Any?, property: KProperty<*>): T = getValue() ?: other
+    operator fun <T> Argument.SingleOrNull<T>.getValue(thisRef: Any?, property: KProperty<*>): T? = getValue()
 }