Object Oriented Programming in NeWS

Created on 2022-09-17T18:02:54-05:00

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Runs PostScript with additions:

Dictionaries: read and write operates on the topmost dictionary of a stack. When no dictionary is there the default is the global dictionary and if a dictionary is pushed then read/write happens to that one.

Dictionaries have prototypes so when something is not found in the dictionary another dictionary is checked for a value.

Messenging is SmallTalk style with a sender capture: push keyword target, push object, call send. Reference to call site is pushed and method is looked up in class heirarchy.

dictbegin/dictend verbs open and close dictionary definitions.

classbegin/classend verbs open and close class definitions.

/NewObject BaseClass
dictbegin % instance variables and their defaults
    /value 0 def
dictend
classbegin
    /classvalue 0 def % class variables and their defaults

    /methodname {
        % does stuff
    } def
classend def