New object (asynchronous constructor)

(newobject)
anewobject [instructions]
(anewobject [instructions] expr1 expr2 ...)
anewobject function
(anewobject function expr1 expr2 ...)

(newo)
anewo [instructions]
(anewo [instructions] expr1 expr2 ...)
anewo function
(anewo function expr1 expr2 ...)

Creates new object. A list of instructions or a function passed as an argument is used as constructor of the new object. The constructor is executed in parallel to subsequent instructions of the turtle/object which called anewobject instruction. The constructor's arguments can be passed as optional expressions.

Object in POOL is a simplified version of a turtle. Objects do not have graphics representation and do not handle events related to graphics (e.g. mouse clicks). Objects use less memory, they are created faster and also execute their tasks faster than turtles.

Example 1:

"t := (newo)
print who
print children
print parent @ :t
print who @ :t

Output:

first
[o1]
first
o1

Example 2:

"t := newo [
"x := 10
print who
]
print :x @ :t

Output:

Note: the message "first" may appear before "o1". The constructor is executed in parallel to instructions of the turtle #first.

first
o1

Example 3:

to model :x
  to fn
    op :variable^2
  end
  wait 50       ;delay
  let "variable :x
  print who
end

"t := (anewo $model 5)
"y := fn @ :t

print who       ;version 1
;(print who :y) ;version 2

Output:

Version 1: the message "first" appears always on top - turtle #first is not waiting for the constructor.

first
model1

Version 2: the message "first 25" appears after "model1" - access to the fn output written in variable :y makes the turtle #first is waiting until the constructor is finished and the function is completed.

model1
first 25

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