Fan

 

abstract class

sys::Obj

Obj is the root class of all classes.

Slots

compareSource

virtual Int compare(Obj that)

Return -1, 0, or 1 if this object is less than, equal to, or greater than the specified object. This method may also be accessed via the < <= <=> >= and > shortcut operators. If not overridden the default implementation compares the toStr() representations.

echoSource

static Void echo(Obj? x)

Write x.toStr to standard output. If x is null then print "null".

equalsSource

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.

hashSource

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.

isImmutableSource

Bool isImmutable()

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

  • an instance of a const class
  • a non-dynamic Type instance
  • the result of List.toImmutable or Map.toImmutable
  • a Func object may or may not be (see sys::Func for details).
  • other instances are assumed mutable and return false.
makeSource

new make()

Obj constructor for subclasses.

toStrSource

virtual Str toStr()

Return a string representation of this object.

trapSource

virtual Obj? trap(Str name, Obj[]? args)

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

a->x        a.trap("x", [,])
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.

typeSource

virtual Type type()

Get the Type instance used to represent this object's type. This method is never overridden directly.