lr_item_core (Java CUP Parser Generator 0.11-a-czt02-SNAPSHOT API)

java.lang.Object
- java_cup.lr_item_core

Direct Known Subclasses:

lalr_item
```
public class lr_item_core
extends Object
```
The "core" of an LR item. This includes a production and the position of a marker (the "dot") within the production. Typically item cores are written using a production with an embedded "dot" to indicate their position. For example:
```
     A ::= B * C d E
  
```
This represents a point in a parse where the parser is trying to match the given production, and has succeeded in matching everything before the "dot" (and hence is expecting to see the symbols after the dot next). See lalr_item, lalr_item_set, and lalr_start for full details on the meaning and use of items.
Version:

last updated: 11/25/95

Author:

Scott Hudson

See Also:

lalr_item, lalr_item_set, lalr_state

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`_core_hash_cache` Cache of the hash code.
`protected int`	`_dot_pos` The position of the "dot" -- this indicates the part of the production that the marker is before, so 0 indicates a dot at the beginning of the RHS.
`protected symbol`	`_symbol_after_dot` Cache of symbol after the dot.
`protected production`	`_the_production` The production for the item.

Constructor Summary

Constructors
Constructor and Description
`lr_item_core(production prod)` Constructor for dot at start of right hand side.
`lr_item_core(production prod, int pos)` Full constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`core_equals(lr_item_core other)` Equality comparison for the core only.
`int`	`core_hashCode()` Hash code for the core (separated so we keep non overridden version).
`boolean`	`dot_at_end()` Is the dot at the end of the production?
`non_terminal`	`dot_before_nt()` Determine if we have a dot before a non terminal, and if so which one (return null or the non terminal).
`int`	`dot_pos()` The position of the "dot" -- this indicates the part of the production that the marker is before, so 0 indicates a dot at the beginning of the RHS.
`boolean`	`equals(lr_item_core other)` Equality comparison.
`boolean`	`equals(Object other)` Generic equality comparison.
`int`	`hashCode()` Hash code for the item.
`protected int`	`obj_hash()` Return the hash code that object would have provided for us so we have a (nearly) unique id for debugging.
`lr_item_core`	`shift_core()` Produce a new lr_item_core that results from shifting the dot one position to the right.
`symbol`	`symbol_after_dot()` Return the symbol after the dot.
`production`	`the_production()` The production for the item.
`String`	`to_simple_string()` Convert to a string (separated out from toString() so we can call it from subclass that overrides toString()).
`String`	`toString()` Convert to a string

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - _the_production
```
protected production _the_production
```
    The production for the item.
  - _dot_pos
```
protected int _dot_pos
```
    The position of the "dot" -- this indicates the part of the production that the marker is before, so 0 indicates a dot at the beginning of the RHS.
  - _core_hash_cache
```
protected int _core_hash_cache
```
    Cache of the hash code.
  - _symbol_after_dot
```
protected symbol _symbol_after_dot
```
    Cache of symbol after the dot.
- Constructor Detail
  - lr_item_core
```
public lr_item_core(production prod,
                    int pos)
             throws internal_error
```
    Full constructor.
    
    Parameters:
    
    prod - production this item uses.
    
    pos - position of the "dot" within the item.
    
    Throws:
    
    internal_error
  - lr_item_core
```
public lr_item_core(production prod)
             throws internal_error
```
    Constructor for dot at start of right hand side.
    
    Parameters:
    
    prod - production this item uses.
    
    Throws:
    
    internal_error
- Method Detail
  - the_production
```
public production the_production()
```
    The production for the item.
  - dot_pos
```
public int dot_pos()
```
    The position of the "dot" -- this indicates the part of the production that the marker is before, so 0 indicates a dot at the beginning of the RHS.
  - dot_at_end
```
public boolean dot_at_end()
```
    Is the dot at the end of the production?
  - symbol_after_dot
```
public symbol symbol_after_dot()
```
    Return the symbol after the dot. If there is no symbol after the dot we return null.
  - dot_before_nt
```
public non_terminal dot_before_nt()
```
    Determine if we have a dot before a non terminal, and if so which one (return null or the non terminal).
  - shift_core
```
public lr_item_core shift_core()
                        throws internal_error
```
    Produce a new lr_item_core that results from shifting the dot one position to the right.
    
    Throws:
    
    internal_error
  - core_equals
```
public boolean core_equals(lr_item_core other)
```
    Equality comparison for the core only. This is separate out because we need separate access in a super class.
  - equals
```
public boolean equals(lr_item_core other)
```
    Equality comparison.
  - equals
```
public boolean equals(Object other)
```
    Generic equality comparison.
    
    Overrides:
    
    equals in class Object
  - core_hashCode
```
public int core_hashCode()
```
    Hash code for the core (separated so we keep non overridden version).
  - hashCode
```
public int hashCode()
```
    Hash code for the item.
    
    Overrides:
    
    hashCode in class Object
  - obj_hash
```
protected int obj_hash()
```
    Return the hash code that object would have provided for us so we have a (nearly) unique id for debugging.
  - to_simple_string
```
public String to_simple_string()
                        throws internal_error
```
    Convert to a string (separated out from toString() so we can call it from subclass that overrides toString()).
    
    Throws:
    
    internal_error
  - toString
```
public String toString()
```
    Convert to a string
    
    Overrides:
    
    toString in class Object

Class lr_item_core

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_the_production

_dot_pos

_core_hash_cache

_symbol_after_dot

Constructor Detail

lr_item_core

lr_item_core

Method Detail

the_production

dot_pos

dot_at_end

symbol_after_dot

dot_before_nt

shift_core

core_equals

equals

equals

core_hashCode

hashCode

obj_hash

to_simple_string

toString