ix.util.lisp
Class Symbol

java.lang.Object
  ix.util.lisp.Symbol

All Implemented Interfaces:

LispObject, SemiPrimitive, java.io.Serializable, java.lang.Comparable

Direct Known Subclasses:

DelimitedSymbol, ItemVar, Keyword

public class Symbol
extends java.lang.Object
implements LispObject, SemiPrimitive, java.lang.Comparable, java.io.Serializable

The root class for Lisp symbols.

The correct way to create a new symbol is to call intern(String name). It will return an instance of Symbol or of an appropriate subclass, typically depending on the first character of the name.

See Also:

Serialized Form

Field Summary

protected java.lang.String	name This Symbol's name.
protected static java.util.Hashtable	obTable The mapping from names to Symbols used to ensure that there is at most one symbol with any given name.

Constructor Summary

protected

Symbol(java.lang.String name) Constructs a Symbol with the specified name and records it as the Symbol that corresponds to that name.

Method Summary

int	compareTo(java.lang.Object o)
static boolean	exists(java.lang.String name) Returns true iff a symbol with the specified name exists.
static Symbol	intern(java.lang.String s) Returns the Symbol that has the specified string as its name, creating a new one only if one does not already exist.
(package private) static Symbol	quickIntern(java.lang.String s) A simple, faster version of intern(String) that is used internally when it's known that the string does not contain any characters that need escaping.
protected java.lang.Object	readResolve()
java.lang.String	toString()
static Symbol	valueOf(java.lang.String name)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

obTable

protected static java.util.Hashtable obTable

The mapping from names to Symbols used to ensure that there is at most one symbol with any given name.

name

protected java.lang.String name

This Symbol's name.

Constructor Detail

Symbol

protected Symbol(java.lang.String name)

Constructs a Symbol with the specified name and records it as the Symbol that corresponds to that name. This Symbol will then be returned by intern(String) whenever it is given that name. This constructor should not normally be called directly. Call intern(String) instead.

Method Detail

intern

public static Symbol intern(java.lang.String s)

Returns the Symbol that has the specified string as its name, creating a new one only if one does not already exist. Thus, there is always at most one Symbol with a given name. This is a factory method that should be called instead of calling any constructor directly. It returns an instance of Symbol, or of an appropriate subclass of Symbol, depending on the characters in the name.

• Keyword if the name begins with ":".
• ItemVar if the name begins with "?".
• NumberlikeSymbol if the name would normally be parsed as an integer or floating-point number.
• DelimitedSymbol if the name would not normally be parsed as a Symbol because it contains whitespace, parentheses, or other syntactically significan characters.
• Symbol in all other cases.

quickIntern

static Symbol quickIntern(java.lang.String s)

A simple, faster version of intern(String) that is used internally when it's known that the string does not contain any characters that need escaping.

exists

public static boolean exists(java.lang.String name)

Returns true iff a symbol with the specified name exists.

compareTo

public int compareTo(java.lang.Object o)

Specified by:

compareTo in interface java.lang.Comparable

readResolve

protected java.lang.Object readResolve()
                                throws java.io.ObjectStreamException

Throws:

java.io.ObjectStreamException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

valueOf

public static Symbol valueOf(java.lang.String name)