LDL++ Source Code

export h_code(R, C).

h_tree(0, X, nil, nil, C, 0) <- freq(X,C).

least(I+1, least<(R, C)>) <- h_tree(I, R, _, _, C, _).

single(least, (R,C), (R,C)).
multi(least, (R,C), (R_old, C_old), (R, C))<-C<C_old.
multi(least, (R,C), (R_old, C_old), (R_old, C_old))<-C>=C_old.

h_tree(I+1, R, S1, S2, C, 1-Odd) <- h_tree(I, R, S1, S2, C, Odd), ~least(I+1,(R,C)).
h_tree(I+1, R, S1, S2, C, 0) <-     
    h_tree(I, _, _, _, _, 1),
    least(I, (S1, C1)),     
    least(I+1, (S2, C2)), 
    C=C1+C2,    
    R=(S1,S2).

h_code(R,C)<-h_tree(_,R,_,_,C,_).