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File: [local] / OpenXM_contrib / PHC / Ada / Root_Counts / Symmetry / symmetry_group.ads (download)
Revision 1.1.1.1 (vendor branch), Sun Oct 29 17:45:31 2000 UTC (23 years, 10 months ago) by maekawa
Import the second public release of PHCpack. OKed by Jan Verschelde. |
with Generic_Lists; with Permutations; use Permutations; package Symmetry_Group is -- DESCRIPTION : -- This package offers operations on elements of a symmetry group. package Lists_of_Permutations is new Generic_Lists(Link_to_Permutation); type List_of_Permutations is new Lists_of_Permutations.List; -- CONSTRUCTORS : procedure Add ( l : in out List_of_Permutations; p : in Permutation ); -- DESCRIPTION : -- Adds the permutation p to the front of the list l. procedure Append ( first,last : in out List_Of_Permutations; p : in Permutation ); -- DESCRIPTION : -- appends the permutation p to the list l1 -- ON ENTRY : -- first a list of permutations; -- last a pointer to the last element of the list first; -- p a permutation. -- ON RETURN : -- first the list to which p has been appended; -- last points to the last element of first. function Union ( a,b : List_of_Permutations ) return List_of_Permutations; -- DESCRIPTION : -- Returns the union of the two groups. function SymGrp ( n : natural ) return List_of_Permutations; -- DESCRIPTION : -- Return the transpositions that generate the full symmetry group -- of all permutations. function Generate ( g : List_of_Permutations ) return List_Of_Permutations; -- DESCRIPTION : -- This functions returns all possible permutations generated by g. -- SELECTORS : function Number ( l : List_of_Permutations ) return natural; -- DESCRIPTION : -- Returns the number of elements in l. function Is_In ( l : List_of_Permutations; p : Permutation ) return boolean; -- DESCRIPTION : -- Returns true if the permutation p belongs to the list l, returns false -- when this is not the case. generic with procedure Process ( p : in Permutation; continue : in out boolean ); procedure Iterator ( l : in List_of_Permutations ); -- DESCRIPTION : -- This iterator allows to enumerate all the elements -- in the list of permutations. -- DESTRUCTOR : procedure Clear ( l : in out List_of_Permutations ); -- DESCRIPTION : -- Deallocates the memory space occupied by the list of permutations. end Symmetry_Group;