/*-----------------------------------------------------------*/
/*--- 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();
}
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Convert to a string (separated out from ToString() so we can call it
* from subclass that overrides ToString()).
*/
public string to_simple_string()
{
string result;
production_part part;
if (_the_production.lhs() != null &&
_the_production.lhs().the_symbol() != null &&
_the_production.lhs().the_symbol().name() != null)
{
result = _the_production.lhs().the_symbol().name();
}
else
{
result = "$$NULL$$";
}
result += " ::= ";
for (int i = 0; i < _the_production.rhs_length(); i++)
{
/* do we need the dot before this one? */
if (i == _dot_pos)
{
result += "(*) ";
}
/* print the name of the part */
if (_the_production.rhs(i) == null)
{
result += "$$NULL$$ ";
}
else
{
part = _the_production.rhs(i);
if (part == null)
{
result += "$$NULL$$ ";
}
else if (part.is_action())
{
result += "{ACTION} ";
}
else if (((symbol_part)part).the_symbol() != null &&
((symbol_part)part).the_symbol().name() != null)
{
result += ((symbol_part)part).the_symbol().name() + " ";
}
else
{
result += "$$NULL$$ ";
}
}
}
/* put the dot after if needed */
if (_dot_pos == _the_production.rhs_length())
{
result += "(*) ";
}
return(result);
}