abstract rtconst class sys::Obj

sys::Obj

Obj is the root class of all classes.

assert

static Void assert(Bool condition, Str msg := "")

throw AssertErr if a boolean condition is false

compare

virtual Int compare(Obj that)

Return a negative integer, zero, or a positive integer if this object is less than, equal to, or greater than the specified object:

this < that   =>  <0
this == that  =>  0
this > that   =>  >0

This method may also be accessed via the < <= <=> >= and > shortcut operators. If not overridden the default implementation compares the toStr representations. Also see docLang.

Examples:

3.compare(8)  =>  -1
8.compare(3)  =>  1
8.compare(8)  =>  0
3 <=> 8       =>  -1  // shortcut for 3.compare(8)
echo

static Void echo(Obj? x := "")

Write x.toStr to standard output followed by newline. If x is null then print "null". If no argument is provided then print an empty line.

equals

virtual Bool equals(Obj? that)

Compare this object to the specified for equality. This method may be accessed via the == and != shortcut operators. If not overridden the default implementation compares for reference equality using the === operator. If this method is overridden, then hash() must also be overridden such that any two objects which return true for equals() must return the same value for hash(). This method must accept null and return false.

finalize

protected virtual Void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

hash

virtual Int hash()

Return a unique hashcode for this object. If a class overrides hash() then it must ensure if equals() returns true for any two objects then they have same hash code.

isImmutable

virtual Bool isImmutable()

Return if this Obj is immutable and safe to share between threads:

  • an instance of a const class
  • the result of List.toImmutable or Map.toImmutable
  • a Func object may or may not be immutable - see Func.
  • other instances are assumed mutable and return false
make

new make()

Obj constructor for subclasses.

toImmutable

virtual Obj toImmutable()

Get an immutable representation of this instance or throw NotImmutableErr if this object cannot be represented as an immutable:

  • if type is const, return this
  • if already an immutable List, Map, or Func return this
  • if a List, then attempt to perform a deep clone by calling toImmutable on all items
  • if a Map, then attempt to perform a deep clone by calling toImmutable on all values (keys are already immutable)
  • some Funcs can be made immutable - see Func
  • any other object throws NotImmutableErr
toStr

virtual Str toStr()

Return a string representation of this object.

trap

virtual Obj? trap(Str name, List<Obj?>? args := null)

Trap a dynamic call for handling. Dynamic calls are invoked with the -> shortcut operator:

a->x        a.trap("x", null)
a->x()      a.trap("x", null)
a->x = b    a.trap("x", [b])
a->x(b)     a.trap("x", [b])
a->x(b, c)  a.trap("x", [b, c])

The default implementation provided by Obj attempts to use reflection. If name maps to a method, it is invoked with the specified arguments. If name maps to a field and args.size is zero, get the field. If name maps to a field and args.size is one, set the field and return args[0]. Otherwise throw UnknownSlotErr.

with

virtual This with(Func<Void,This> f)

This method called whenever an it-block is applied to an object. The default implementation calls the function with this, and then returns this.