%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%  visualize.P
%%%%  Tell Java to display rule trees.
%%%%  JRFisher @CSUPomona.edu
%%%%  Fall 1999.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% The tree expression operator. 
:- op(100,xfx,'#').


% Let Java display the tree
visualize(Goal) :- 
   ctie(Goal,[],Tree), 
   make_tree_expression(Tree,TreeExpressionList), 
   tell('tree.txt'),
   write(TreeExpressionList), 
   told,
   writeln('<<View Rule Tree>>').

% shorthand
vis(Goal) :- visualize(Goal).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
%%  Construct a Prolog expression which when printed 
%%  gives a tree expression. The Prolog form of such
%%  an expresion is [<root> # [ <sequence of branches>]].
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

make_tree_expression(tree(Root,Branches),[Root # ChildList]) :- ! ,
   make_list(Branches,ChildList).   
make_tree_expression(true, [true # []]) :- ! . 
make_tree_expression(ancestor_resolution(X), [X # []]) :- ! . 

make_list((B,Bs),[Btree | BsTree]) :- ! , 
   make_tree_expression(B,Btree),
   make_list(Bs,BsTree).
make_list((B),[Btree]) :- 
   make_tree_expression(B,Btree).



% load normal prolog interpreter
:- [npl].