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-- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
--                                                                          --
-- (C) 2019 Stanislav Datskovskiy ( www.loper-os.org )                      --
-- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
--                                                                          --
-- You do not have, nor can you ever acquire the right to use, copy or      --
-- distribute this software ; Should you use this software for any purpose, --
-- or copy and distribute it to anyone or in any manner, you are breaking   --
-- the laws of whatever soi-disant jurisdiction, and you promise to         --
-- continue doing so for the indefinite future. In any case, please         --
-- always : read and understand any software ; verify any PGP signatures    --
-- that you use - for any purpose.                                          --
--                                                                          --
-- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
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with Limits;   use Limits;
with FFA_RNG;  use FFA_RNG;


package FFA_Calc is
   
   -- Peh Tapes:
   subtype Peh_Tape_Range is Positive range 1 .. Max_Peh_TapeSpace;
   type Peh_Tapes is array(Peh_Tape_Range range <>) of Character;
   
   -- Possible Verdicts of a non-erroneous Peh Tape run:
   type Peh_Verdicts is (Yes, No, Mu);
   
   -- Operator-Selectable Spatial and Time Dimensions of a Peh Machine:
   type Peh_Dimensions is
      record
         Width     : Positive;
         Height    : Positive;
         TapeSpace : Peh_Tape_Range;
         Life      : Natural;
      end record;
   
   -- Valid indices into the Control Stack:
   subtype ControlStack_Range is Natural range 0 .. Peh_Control_Stack_Size;
   -- The 'zero' position, as with the Data Stack, indicates 'emptiness'
   -- when pointed to by CSP ( see ffa_calc.adb ) and is never accessed.
   
   -- Ensure that requested Peh Dimensions are permissible. Terminate if not.
   procedure Validate_Peh_Dimensions(Dimensions : in Peh_Dimensions);
   
   -- Start a Peh Machine with the given Dimensions and Tape; return a Verdict.
   function Peh_Machine(Dimensions : in Peh_Dimensions;
                        Tape       : in Peh_Tapes;
                        RNG        : in RNG_Device) return Peh_Verdicts;
   
end FFA_Calc;