/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/** Full constructor.
* @param prod production this item uses.
* @param pos position of the "dot" within the item.
*/
public lr_item_core(production prod, int pos)
{
production_part part;
if (prod == null)
{
throw new internal_error(
"Attempt to create an lr_item_core with a null production");
}
_the_production = prod;
if (pos < 0 || pos > _the_production.rhs_length())
{
throw new internal_error(
"Attempt to create an lr_item_core with a bad dot position");
}
_dot_pos = pos;
/* compute and cache hash code now */
_core_hash_cache = 13 * _the_production.GetHashCode() + pos;
/* cache the symbol after the dot */
if (_dot_pos < _the_production.rhs_length())
{
part = _the_production.rhs(_dot_pos);
if (!part.is_action())
{
_symbol_after_dot = ((symbol_part)part).the_symbol();
}
}
}
/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/** Full constructor.
* @param prod production this item uses.
* @param pos position of the "dot" within the item.
*/
public lr_item_core(production prod, int pos) {
production_part part;
if (prod == null)
throw new internal_error(
"Attempt to create an lr_item_core with a null production");
_the_production = prod;
if (pos < 0 || pos > _the_production.rhs_length())
throw new internal_error(
"Attempt to create an lr_item_core with a bad dot position");
_dot_pos = pos;
/* compute and cache hash code now */
_core_hash_cache = 13*_the_production.GetHashCode() + pos;
/* cache the symbol after the dot */
if (_dot_pos < _the_production.rhs_length())
{
part = _the_production.rhs(_dot_pos);
if (!part.is_action())
_symbol_after_dot = ((symbol_part)part).the_symbol();
}
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Is the dot at the end of the production? */
public bool dot_at_end()
{
return(_dot_pos >= _the_production.rhs_length());
}