| java.lang.Object
 net.sourceforge.chaperon.build.ItemSet
| ItemSet | | public class ItemSet (Code) | | This class represents a set of items, which means positions of production, in production and
lookahead symbols. These item sets were used to decribes states.
author:
Stephan Michels
version:
CVS $Id: ItemSet.java,v 1.17 2003/12/09 19:55:52 benedikta Exp $ |
| Method Summary | |
| public boolean | addItem(int production, int position, Symbol lookahead)
Add a item to this set.
Parameters:
production - Production.
Parameters:
position - Position in this production.
Parameters:
lookahead - Lookahead symbol. | | public boolean | addItem(int production, int position, SymbolSet lookaheads)
| | public boolean | addItemSet(ItemSet I)
Add the items from another itemset to this set. | | public ItemSet | closure()
Calculate the closure for this item set. | | public boolean | contains(ItemSet itemset)
Test, if all items from a other state exists in this state
Parameters:
itemset - Other item set. | | public boolean | equals(Object o)
Compares two item sets.
Parameters:
o - Other itemset. | | public boolean | equalsCore(Object o)
Compares the core of two item sets.
Parameters:
o - Other itemset. | | public int | getItemCount()
Returns the count of items in this set. | | public Error | getNextError()
| | public SymbolSet | getNextNonterminals()
| | public SymbolSet | getNextTerminals()
| | public IntegerSet | getReduceProductions()
Returns the list of productions, which could be reduced. | | public IntegerSet | getReduceProductions(Symbol lookahead)
Returns the list of productions, which a special symbol reduce.
Parameters:
lookahead - Symbol, which the productions reduce. | | public SymbolSet | getReduceSymbols()
Return all symbols, which reduce productions in this state. | | public SymbolSet | getShiftSymbols()
Returns all symbols, which forces a transition. | | public int | getTransition(Symbol symbol)
Returns the destination state of a transition.
Parameters:
symbol - Symbol, which force the transition. | | public boolean | isEmpty()
Returns true, if this set is empty. | | public ItemSet | jump(Symbol symbol)
Calculates the next state by a transition through the symbol X.
Parameters:
symbol - A Symbol, which can be a terminal or a nonterminal symbol. | | public void | setTransition(Symbol symbol, int state)
Add a transition to this state. | | public String | toString()
Return a string representation of this item set. |
| ItemSet | | public ItemSet(Grammar grammar, FirstSetCollection firstsets)(Code) | | Create an empty set of items.
Parameters:
grammar - Grammar.
Parameters:
firstsets - The first sets. |
| addItem | | public boolean addItem(int production, int position, Symbol lookahead)(Code) | | Add a item to this set.
Parameters:
production - Production.
Parameters:
position - Position in this production.
Parameters:
lookahead - Lookahead symbol. True, if this item was added |
| addItem | | public boolean addItem(int production, int position, SymbolSet lookaheads)(Code) | | |
| addItemSet | | public boolean addItemSet(ItemSet I)(Code) | | Add the items from another itemset to this set. If this set changed the method will return
true.
Parameters:
I - ItemSet, which should be addded. True, if this set was changed |
| closure | | public ItemSet closure()(Code) | | Calculate the closure for this item set.
Closure of the item set |
| contains | | public boolean contains(ItemSet itemset)(Code) | | Test, if all items from a other state exists in this state
Parameters:
itemset - Other item set. True, if the state contains all items. |
| equals | | public boolean equals(Object o)(Code) | | Compares two item sets.
Parameters:
o - Other itemset. True, if the item sets are equal. |
| equalsCore | | public boolean equalsCore(Object o)(Code) | | Compares the core of two item sets.
Parameters:
o - Other itemset. True, if the core of the itemsets are equal. |
| getItemCount | | public int getItemCount()(Code) | | Returns the count of items in this set.
Count of items of the core. |
| getReduceProductions | | public IntegerSet getReduceProductions()(Code) | | Returns the list of productions, which could be reduced.
List of indicies for the productions. |
| getReduceProductions | | public IntegerSet getReduceProductions(Symbol lookahead)(Code) | | Returns the list of productions, which a special symbol reduce.
Parameters:
lookahead - Symbol, which the productions reduce. Set of indicies from the productions. |
| getReduceSymbols | | public SymbolSet getReduceSymbols()(Code) | | Return all symbols, which reduce productions in this state.
Set of symbols. |
| getShiftSymbols | | public SymbolSet getShiftSymbols()(Code) | | Returns all symbols, which forces a transition.
List of symbols. |
| getTransition | | public int getTransition(Symbol symbol)(Code) | | Returns the destination state of a transition.
Parameters:
symbol - Symbol, which force the transition. Destination state. |
| isEmpty | | public boolean isEmpty()(Code) | | Returns true, if this set is empty.
True, if this set is empty. |
| jump | | public ItemSet jump(Symbol symbol)(Code) | | Calculates the next state by a transition through the symbol X.
Parameters:
symbol - A Symbol, which can be a terminal or a nonterminal symbol. The next state, represented by an item set. |
| setTransition | | public void setTransition(Symbol symbol, int state)(Code) | | Add a transition to this state.
Parameters:
symbol - Symbol, which forces a transition into another state.
Parameters:
state - Destination state. |
| toString | | public String toString()(Code) | | Return a string representation of this item set.
String representation of this item set. |
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