Hi all,
I would like to propose a reorganisation for CDKConstants classes. This class as you know, provide a predefined values for a number of constants used throughout the CDK. 
It has numerical static values like BONDORDER_SINGLE = 1.0, HYBRIDIZATION_SP1 = 0, and so on. And string static definitions. A lot of the will be used like Flags. 
But a bit problem with the numerical values is to repeat their self with that will cause errors.


So the idea is to separate into groups and put consecutively their values:


1: type bond (0-5)
-BONDORDER_SINGLE = 1.0
-BONDORDER_AROMATIC = 1.5;
-BONDORDER_DOUBLE = 2.0;
-BONDORDER_TRIPLE = 3.0;

2: type stereo bond (10-15)
-STEREO_BOND_NONE = 10;
-STEREO_BOND_UNDEFINED = 11;
-STEREO_BOND_UP = 12;
-STEREO_BOND_UP_INV = 13;
-STEREO_BOND_DOWN = 14;
-STEREO_BOND_DOWN_INV = 15;

3: type stereo atom (20-25)
-STEREO_ATOM_PARITY_UNDEFINED = 20;
-STEREO_ATOM_PARITY_PLUS = 21;
-STEREO_ATOM_PARITY_MINUS = 22;

3: type hybridization (30-39)
-HYBRIDIZATION_UNSET = 30;
-HYBRIDIZATION_SP1 = 31;
-HYBRIDIZATION_SP2 = 32;
-HYBRIDIZATION_SP3 = 33;
-HYBRIDIZATION_SP3D1 = 34;
-HYBRIDIZATION_SP3D2 = 35;
-HYBRIDIZATION_SP3D3 = 36;
-HYBRIDIZATION_SP3D4 = 37;
-HYBRIDIZATION_SP3D5 = 38;

3: type chemObject properties (40-49)
-ISPLACED = 40
-ISINRING = 41;
-ISALIPHATIC = 42;
-VISITED = 43; 
-ISAROMATIC = 44;
-ISCONJUGATED = 45;
-MAPPED = 46;
-IS_HYDROGENBOND_DONOR = 47;
-IS_HYDROGENBOND_ACCEPTOR = 48;
-REACTIVE_CENTER = 49;

4:
-MAX_FLAG_INDEX = 50;

remove static values. They are not used:
-DUMMY_POINTER
-MAX_POINTER_INDEX 


Chers,
 Rojas