Category : Miscellaneous Language Source Code
Archive   : PROLOG19.ZIP
Filename : MEXP.PRO

begin :-
print( 'What is the name of the input file? : '),
ratom( File ),
open( File, r ),
print( 'How many iterations? : '),
rnum( N ),
docalc( N, File ),
close( File ).

docalc( N, File ) :- N > 0,
M is N - 1,
calculate( File ),
docalc( M, File ).

docalc( 0, _ ).

calculate( Source ) :-

/* Read in 2 elements: */
readlist_n( Parset, Source, 2 ),
listval( Parset, 0, 1 ),

/* Typical formats: '3.5g', '5.7e', etc. */
open( mathout, wr ),
wrlist( Parset, mathout ),
close( mathout ),
exec( calc ),
/* Read mathinps from file test5 wrote: */
open( mathinp, r ),
readlist( Num_list, mathinp ),
close( mathinp ),
/* Display results: */
print('\nAnd now, the results: '),
prt_numlist( Num_list ).

/* Numlist will be of the form: Numlist = [ 12345, 5678 ]. */


readlist( [H|T], File ) :- rnum( H, File), readlist( T, File ).
readlist( [], _ ).

readlist_n( [H|T], File,N ) :-
N > 0, M is N - 1,
rnum( H, File),
readlist_n( T, File, M ).

readlist_n( [], _, 0 ).

doinp(X) :- open( mathinp, r ),
readlist( X, mathinp ),
close( mathinp ).


query( X, Argnum ) :-
print('\nWhat is the', Argnum, 'argument:\n\t' ),
rnum( X ).

listval( [H|T], Lower, Upper ) :-
H > Lower,
H < Upper,
listval( T, Lower, Upper ).
listval( [], _, _ ).


valid( X ) :- X < 1, X > 0.


prt_numlist( [] ).
prt_numlist( [H|T] ) :-
wrnum( user, H, '5.5f' ),
print( ' , ' ),
prt_numlist( T ).


wrlist( [H|T], Stream ) :-
wrnum( Stream, H, '3.3f' ), nlf( Stream ),
wrlist( T, Stream ).

wrlist( [], _ ).