37 lines
1.9 KiB
Plaintext
37 lines
1.9 KiB
Plaintext
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%hr/
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%p
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layout: typed
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title: Parfait, a minimal runtime
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—
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%h3#type-and-class Type and Class
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%p
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Each object has a type that describes the instance variables and basic types of the object.
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Types also reference the class they implement.
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Type objects are unique and constant, may not be changed over their lifetime.
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When a field is added to a class, a new Type is created. For a given class and combination
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of instance names and basic types, only one instance every exists describing that type (a bit
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similar to symbols)
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%p
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A Class describes a set of objects that respond to the same methods (the methods source is stored
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in the RubyMethod class).
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A Type describes a set of objects that have the same instance variables.
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%h3#method-message-and-frame Method, Message and Frame
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%p
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The TypedMethod class describes a callable method. It carries a name, argument and local variable
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type and several descriptions of the code.
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The typed ast is kept for debugging, the register model instruction stream for optimisation
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and further processing and finally the cpu specific binary
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represents the executable code.
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%p
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When TypedMethods are invoked, A message object (instance of Message class) is populated.
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Message objects are created at compile time and form a linked list.
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The data in the Message holds the receiver, return addresses, arguments and a frame.
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Frames are also created at compile time and just reused at runtime.
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%h3#space-and-support Space and support
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%p
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The single instance of Space hold a list of all Types and all Classes, which in turn hold
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the methods.
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Also the space holds messages and will hold memory management objects like pages.
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%p Words represent short immutable text and other word processing (buffers, text) is still tbd.
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%p Lists (aka Array) are number indexed, starting at one, and dictionaries (aka Hash) are mappings from words to objects.
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