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the interaction of gsave/grestore and save/restore

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Understanding this part of postscript has taken me a rather 
long time, so I present a rant and ramble about "what's the diff?"

The graphics state is an object in local VM.

gsave and grestore implement some kind of stack at the ps-level 
which creates copies and makes redefinitions to manage a graphics
stack as a postscript abstract data type (probably an array and 
index pair defined in a dictionary).

Arrays and Dicts are VM objects.

Therefore save and restore which operate on VM as a whole,
naturally produce the desired effects upon the VM structures that
comprise the graphics state data structure, without any special-cases. 
Because it's built out of arrays and dicts, and all arrays and dicts 
get reverted by restore.

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the interaction of gsave/grestore and save/restore luser- -droog <mijoryx@yahoo.com> - 2013-11-30 20:32 -0800

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