/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/// <summary>Simple constructor. All terminals, non-terminals, and productions must
/// already have been entered, and the viable prefix recognizer should
/// have been constructed before this is called.
/// </summary>
public parse_action_table()
{
/* determine how many states we are working with */
_num_states = lalr_state.number();
/* allocate the array and fill it in with empty rows */
under_state = new parse_action_row[_num_states];
for (int i = 0; i < _num_states; i++)
under_state[i] = new parse_action_row();
}
/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/// <summary>Simple constructor. All terminals, non-terminals, and productions must
/// already have been entered, and the viable prefix recognizer should
/// have been constructed before this is called.
/// </summary>
public parse_action_table()
{
/* determine how many states we are working with */
_num_states = lalr_state.number();
/* allocate the array and fill it in with empty rows */
under_state = new parse_action_row[_num_states];
for (int i = 0; i < _num_states; i++)
{
under_state[i] = new parse_action_row();
}
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/// <summary>Procedure that attempts to fix a shift/reduce error by using
/// precedences. --frankf 6/26/96
///
/// if a production (also called rule) or the lookahead terminal
/// has a precedence, then the table can be fixed. if the rule
/// has greater precedence than the terminal, a reduce by that rule
/// in inserted in the table. If the terminal has a higher precedence,
/// it is shifted. if they have equal precedence, then the associativity
/// of the precedence is used to determine what to put in the table:
/// if the precedence is left associative, the action is to reduce.
/// if the precedence is right associative, the action is to shift.
/// if the precedence is non associative, then it is a syntax error.
/// *
/// </summary>
/// <param name="p"> the production
/// </param>
/// <param name="term_index"> the index of the lokahead terminal
/// </param>
/// <param name="parse_action_row"> a row of the action table
/// </param>
/// <param name="act"> the rule in conflict with the table entry
///
/// </param>
protected internal virtual bool fix_with_precedence(production p, int term_index, parse_action_row table_row, parse_action act)
{
terminal term = terminal.find(term_index);
/* if the production has a precedence number, it can be fixed */
if (p.precedence_num() > assoc.no_prec)
{
/* if production precedes terminal, put reduce in table */
if (p.precedence_num() > term.precedence_num())
{
table_row.under_term[term_index] = insert_reduce(table_row.under_term[term_index], act);
return true;
}
else if (p.precedence_num() < term.precedence_num())
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return true;
}
else
{
/* they are == precedence */
/* equal precedences have equal sides, so only need to
look at one: if it is right, put shift in table */
if (term.precedence_side() == assoc.right)
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return true;
}
else if (term.precedence_side() == assoc.left)
{
table_row.under_term[term_index] = insert_reduce(table_row.under_term[term_index], act);
return true;
}
else if (term.precedence_side() == assoc.nonassoc)
{
table_row.under_term[term_index] = new nonassoc_action();
return true;
}
else
{
/* something really went wrong */
throw new internal_error("Unable to resolve conflict correctly");
}
}
}
else if (term.precedence_num() > assoc.no_prec)
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return true;
}
/* otherwise, neither the rule nor the terminal has a precedence,
so it can't be fixed. */
return false;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/// <summary>Procedure that attempts to fix a shift/reduce error by using
/// precedences. --frankf 6/26/96
///
/// if a production (also called rule) or the lookahead terminal
/// has a precedence, then the table can be fixed. if the rule
/// has greater precedence than the terminal, a reduce by that rule
/// in inserted in the table. If the terminal has a higher precedence,
/// it is shifted. if they have equal precedence, then the associativity
/// of the precedence is used to determine what to put in the table:
/// if the precedence is left associative, the action is to reduce.
/// if the precedence is right associative, the action is to shift.
/// if the precedence is non associative, then it is a syntax error.
/// *
/// </summary>
/// <param name="p"> the production
/// </param>
/// <param name="term_index"> the index of the lokahead terminal
/// </param>
/// <param name="parse_action_row"> a row of the action table
/// </param>
/// <param name="act"> the rule in conflict with the table entry
///
/// </param>
protected internal virtual bool fix_with_precedence(production p, int term_index, parse_action_row table_row, parse_action act)
{
terminal term = terminal.find(term_index);
/* if the production has a precedence number, it can be fixed */
if (p.precedence_num() > assoc.no_prec)
{
/* if production precedes terminal, put reduce in table */
if (p.precedence_num() > term.precedence_num())
{
table_row.under_term[term_index] = insert_reduce(table_row.under_term[term_index], act);
return(true);
}
else if (p.precedence_num() < term.precedence_num())
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return(true);
}
else
{
/* they are == precedence */
/* equal precedences have equal sides, so only need to
* look at one: if it is right, put shift in table */
if (term.precedence_side() == assoc.right)
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return(true);
}
else if (term.precedence_side() == assoc.left)
{
table_row.under_term[term_index] = insert_reduce(table_row.under_term[term_index], act);
return(true);
}
else if (term.precedence_side() == assoc.nonassoc)
{
table_row.under_term[term_index] = new nonassoc_action();
return(true);
}
else
{
/* something really went wrong */
throw new internal_error("Unable to resolve conflict correctly");
}
}
}
else if (term.precedence_num() > assoc.no_prec)
{
table_row.under_term[term_index] = insert_shift(table_row.under_term[term_index], act);
return(true);
}
/* otherwise, neither the rule nor the terminal has a precedence,
* so it can't be fixed. */
return(false);
}
