class

Krikri::VariableSubstitutor::Undefined

The engine's real undefined marker - a distinct TYPE, deliberately not a String. The hand-rolled evaluator's historical representation of "this reference has no value" is the literal text "undefined" (120+ production sites), which any real stored value can collide with: command: printf 'undefined' + register: s2, then {{ s2.stdout_lines.0 }} - real Ansible renders the string; a strict-undefined check that re-reads the evaluator's own rendered output cannot tell a genuine miss from that collision and failed the task with "'s2.stdout_lines.0' is undefined" (juju4.pocketid, round 60151; see KNOWN_MISSING.md's dotted-index entry).

New code threads THIS type through the seam instead: it is produced only by an actual miss decision (never by a lookup that succeeded), it is never == to any String, and its to_s renders the same lenient "undefined" text the string sentinel always has, so materializing it at a String boundary is behavior-preserving.

Constants

INSTANCE = new

Instance methods

to_s(io : IO) : Nil

Appends a short String representation of this object which includes its class name and its object address.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).to_s # => #<Person:0x10a199f20>

Source