int
main( int argc, char *argv[] )
{
istream *br;
ifstream infile;
if( argc == 1 )
br = &cin;
else if( argc == 2 ) {
infile.open(argv[1]);
if( infile.is_open() )
br = &infile;
else {
usage(argv[0], "Cannot open " + string(argv[1]));
return 1;
}
}
else {
usage(argv[0], "More than one file name was given");
return 1;
}
PTree *program;
program = Program(br);
//evaluate the program
program->eval();
}
