Class AbstractSymbol

java.lang.Object
  AbstractSymbol

Direct Known Subclasses:

IdSymbol, IntSymbol, StringSymbol

abstract class AbstractSymbol
extends java.lang.Object

String table entry There are three kinds of string table entries:

• a true string,
• a string representation of an identifier, and
• a string representation of an integer.

Having separate tables is convenient for code generation. Different data definitions are generated for string constants (StringSymbol) and integer constants (IntSymbol). Identifiers (IdSymbol) don't produce static data definitions.

codeDef and codeRef (defined by subclasses) are used by the code to produce definitions and references (respectively) to constants.

See Also:

AbstractTable

Field Summary

protected int	index The index of this entry in the string table
protected java.lang.String	str The stored string

Constructor Summary

AbstractSymbol(java.lang.String str, int len, int index)
Constructs a new table entry.

Method Summary

abstract java.lang.Object	clone() Returns a copy of this symbol
boolean	equals(java.lang.Object another) Tests if two symbols are equal.
boolean	equalsIndex(int index) Tests if the index argument is equal to the index of this symbol.
boolean	equalString(java.lang.String str, int len) Tests if the string argument is equal to the string in this symbol.
java.lang.String	getString() Returns the string representation of this symbol.
java.lang.String	toString() Returns a printable representation of this symbol.

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

str

protected java.lang.String str

The stored string

index

protected int index

The index of this entry in the string table

Constructor Detail

AbstractSymbol

public AbstractSymbol(java.lang.String str,
                      int len,
                      int index)

Constructs a new table entry.

Parameters:

str - the entry string

len - the length of the str prefix that is acually used

index - the table index

Method Detail

equalString

public boolean equalString(java.lang.String str,
                           int len)

Tests if the string argument is equal to the string in this symbol.

Parameters:

str - the string to compare

Returns:

true if the strings are equal

equalsIndex

public boolean equalsIndex(int index)

Tests if the index argument is equal to the index of this symbol. It is only meaningful to compare indecies of symbols from the same string table.

Parameters:

index - the index to compare

Returns:

true if the indecies are equal

equals

public boolean equals(java.lang.Object another)

Tests if two symbols are equal. Symbol equality is equivalent to equality of their indecies, so it is only meaningful to compare symbols that came from the same string table.

Overrides:

equals in class java.lang.Object

Parameters:

another - the other symbol

Returns:

true if the symbols are equal

getString

public java.lang.String getString()

Returns the string representation of this symbol.

toString

public java.lang.String toString()

Returns a printable representation of this symbol.

Overrides:

toString in class java.lang.Object

clone

public abstract java.lang.Object clone()

Returns a copy of this symbol

Overrides:

clone in class java.lang.Object