language · language ·

Type checks and casts

is asks whether a value has a named type; as requests a cast to that named type.

ascpuislanguagelogicyeho

Prefer designs that already know their types. Use is/as at admitted dynamic boundaries and keep failure handling explicit.

value is Type
value as Type

Status: experimental

Complete program

Use a checked class boundary before reading the pilot-specific callsign.

cpu · language · type checked

class Actor { }
class Pilot extends Actor { text callsign = "Nova" }
Actor actor = Pilot()
if actor is Pilot
{
    Pilot pilot = actor as Pilot
    Console.Log(pilot.callsign)
}
project.mech
manifestVersion = "2"
package = "api.example.language__casts_type_checks"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"
Notes and source

Complete class/reference flow is oracle-only today, so this is not a general Kyber dynamic-object promise.

The target after is or as is currently a named type.

yeho/parser_expressions.cpp parseComparison; semantic/expr.cpp