Java Language Specification - Revision history

Egge at 02:48, 10 November 2007

2007-11-10T02:48:26Z

← Older revision		Revision as of 02:48, 10 November 2007
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	I've been reading the [http://java.sun.com/docs/books/jls/third_edition/html/ Java Language Specification] to improve my knowledge of the Java language. Here's a list of things I've learned:		I've been reading the [http://java.sun.com/docs/books/jls/third_edition/html/j3TOC.html Java Language Specification] to improve my knowledge of the Java language. Here's a list of things I've learned:

	== $ identifier ==		== $ identifier ==

Egge: /* [http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.10.2 Hexadecimal Floating Point Literals] */

2007-11-07T00:37:39Z

[http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.10.2 Hexadecimal Floating Point Literals]

← Older revision		Revision as of 00:37, 7 November 2007
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	</geshi>		</geshi>

	I can find no examples on the Internet of anyone using this feature, ~~and Eclipse barfs when~~ I ~~try to use it there~~. ~~However, javac compiles them and they run just fine~~.		I can find no examples on the Internet of anyone using this feature in production code, although I did find a few other [http://www.davidflanagan.com/blog/000044.html samples]. It was an obscure feature introduced with Java 5.0.

	<geshi lang="java5">		<geshi lang="java5">
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	}		}
	}		}

	</geshi>		</geshi>

Egge at 00:30, 7 November 2007

2007-11-07T00:30:19Z

← Older revision		Revision as of 00:30, 7 November 2007
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	</geshi>		</geshi>

			== [http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.10.2 Hexadecimal Floating Point Literals] ==

			I never knew about this part of the grammar.

			<geshi lang="bnf">
			HexadecimalFloatingPointLiteral:
			HexSignificand BinaryExponent FloatTypeSuffixopt

			HexSignificand:
			HexNumeral
			HexNumeral .
			0x HexDigitsopt . HexDigits
			0X HexDigitsopt . HexDigits

			BinaryExponent:
			BinaryExponentIndicator SignedInteger

			BinaryExponentIndicator:one of
			p P
			</geshi>

			I can find no examples on the Internet of anyone using this feature, and Eclipse barfs when I try to use it there. However, javac compiles them and they run just fine.

			<geshi lang="java5">
			public class A {
			static double f = 0xF.Fp-1D;
			static double pi = Double.longBitsToDouble(0x400921FB54442D18L);
			static double π = 0x3.243F6A8885A308D31319p+0;
			public static void main(String[] args) {
			System.out.println(f);
			System.out.println(pi);
			System.out.println(π);
			System.out.println(pi == π);
			}
			}

			</geshi>

			The output is:
			<pre>
			7.96875
			3.141592653589793
			3.141592653589793
			true
			</pre>

			Unfortunately the exponent must be a signed integer, which prevents creating literals like <code>g0pee</code>;

	== [http://java.sun.com/docs/books/jls/third_edition/html/conversions.html#184206 Assignment Conversions] ==		== [http://java.sun.com/docs/books/jls/third_edition/html/conversions.html#184206 Assignment Conversions] ==

Egge at 07:15, 5 November 2007

2007-11-05T07:15:04Z

← Older revision		Revision as of 07:15, 5 November 2007
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	int $$;String $0="$";$ $;		int $$;String $0="$";$ $;
	$ $(){if($$==0)System.out.println($0!=$?$0:$);return $;}		$ $(){if($$==0)System.out.println($0!=$?$0:$);return $;}
			public static void main(String args[]) { new Test().$();}
	}		}
	</geshi>		</geshi>

Egge at 03:30, 3 November 2007

2007-11-03T03:30:09Z

@@ Line 12: / Line 12: @@
+}
 </geshi>
 [[Category:Java]]

Egge at 07:15, 2 November 2007

2007-11-02T07:15:11Z

← Older revision		Revision as of 07:15, 2 November 2007
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	This means I can make my Java programs look like Perl.		This means I can make my Java programs look like Perl.
	<geshi lang="java5">		<geshi lang="java5">
	int $$;String $0="$",$;		public class Test<$> {
	~~void~~ $(){if($$==0)System.out.println($0!=$?$0:$);}		int $$;String $0="$";$ $;
			$ $(){if($$==0)System.out.println($0!=$?$0:$);return $;}
			}
	</geshi>		</geshi>

	[[Category:Java]]		[[Category:Java]]

Egge at 06:47, 2 November 2007

2007-11-02T06:47:58Z

← Older revision		Revision as of 06:47, 2 November 2007
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	This means I can make my Java programs look like Perl.		This means I can make my Java programs look like Perl.
	<geshi lang="java5">		<geshi lang="java5">
	int $$ ~~= 123~~;		int $$;String $0="$",$;
	String $0 = "~~app~~";		void $(){if($$==0)System.out.println($0!=$?$0:$);}
	void $(){if($$!=0)System.out.println($0);}
	</geshi>		</geshi>

	[[Category:Java]]		[[Category:Java]]

Egge: New page: I've been reading the [http://java.sun.com/docs/books/jls/third_edition/html/ Java Language Specification] to improve my knowledge of the Java language. Here's a list of things I've learn...

2007-11-02T06:28:52Z

New page: I've been reading the [http://java.sun.com/docs/books/jls/third_edition/html/ Java Language Specification] to improve my knowledge of the Java language. Here's a list of things I've learn...

New page

I've been reading the [http://java.sun.com/docs/books/jls/third_edition/html/ Java Language Specification] to improve my knowledge of the Java language. Here's a list of things I've learned:

== $ identifier ==
[http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#40625 The $ character can be part of a Java identifier]. "for historical reasons, the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $ character should be used only in
mechanically generated source code or, rarely, to access preexisting names on legacy systems."

This means I can make my Java programs look like Perl.
<geshi lang="java5">
int $$ = 123;
String $0 = "app";
void $(){if($$!=0)System.out.println($0);}
</geshi>

[[Category:Java]]