rename Arguments to Options, implement Arguments

src/commonMain/kotlin/com/infendro/cli/command/Argument.kt

@@ -0,0 +1,79 @@
+package com.infendro.cli.command
+
+import com.infendro.cli.parser.BooleanParser
+import com.infendro.cli.parser.IntParser
+import com.infendro.cli.parser.Parser
+import com.infendro.cli.parser.StringParser
+
+sealed class Argument<T>(
+    val parser: Parser<T>,
+) {
+    abstract val required: Boolean
+
+    class Required<T>(
+        parser: Parser<T>,
+    ) : Argument<T>(parser) {
+        override val required: Boolean
+            get() = true
+    }
+
+    class OrElse<T>(
+        val other: T,
+        parser: Parser<T>,
+    ) : Argument<T>(parser) {
+        override val required: Boolean
+            get() = false
+    }
+
+    class OrNull<T>(
+        parser: Parser<T>,
+    ) : Argument<T>(parser) {
+        override val required: Boolean
+            get() = false
+    }
+
+    class Variable<T>(
+        parser: Parser<T>,
+    ) : Argument<T>(parser) {
+        override val required: Boolean
+            get() = false
+    }
+
+    companion object {
+        fun string() =
+            Required(StringParser)
+
+        fun stringOrElse(other: String) =
+            OrElse(other, StringParser)
+
+        fun stringOrNull() =
+            OrNull(StringParser)
+
+        fun strings() =
+            Variable(StringParser)
+
+        fun int() =
+            Required(IntParser)
+
+        fun intOrElse(other: Int) =
+            OrElse(other, IntParser)
+
+        fun intOrNull() =
+            OrNull(IntParser)
+
+        fun ints() =
+            Variable(IntParser)
+
+        fun boolean() =
+            Required(BooleanParser)
+
+        fun booleanOrElse(other: Boolean) =
+            OrElse(other, BooleanParser)
+
+        fun booleanOrNull() =
+            OrNull(BooleanParser)
+
+        fun booleans() =
+            Variable(BooleanParser)
+    }
+}