split error and exception

src/commonMain/kotlin/com/infendro/cli/error/UnknownOption.kt

@@ -0,0 +1,24 @@
+package com.infendro.cli.error
+
+import com.infendro.cli.command.Command
+import com.infendro.cli.util.distance
+import com.infendro.cli.util.threshold
+import kotlin.math.min
+
+class UnknownOption(
+    val command: Command,
+    val name: String,
+) : Error() {
+    override val message: String
+        get() = buildString {
+            val suggestion = command.options
+                .flatMap { it.names }
+                .associateWith { distance(name, it) }
+                .filter { it.value <= min(it.key.length - 1, threshold) }
+                .minByOrNull { it.value }
+                ?.key
+
+            append("""Unknown option "$name".""")
+            if (suggestion != null) append(""" Did you mean "$suggestion"?""")
+        }
+}