Bck2BrwsrMangling - Revision history

JaroslavTulach: /* Accessing a Field */

2013-02-27T13:44:38Z

Accessing a Field

←Older revision		Revision as of 13:44, 27 February 2013
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	</source>		</source>

-	=== Accessing a Field ===	+	=== Accessing an Instance Field ===

	To support subclasses defining the same field (like in case of [http://source.apidesign.org/hg/bck2brwsr/rev/5e13b1ac2886 InheritanceA and InheritanceB classes]) the [[Bck2Brwsr]] needed to create accessor method to access each field in its declaring class. The accessor which prefixes the name of the field with "_" (forming a name that can't clash with mangled method names). The proper way to access field ''value'' defined in String class would then be:		To support subclasses defining the same field (like in case of [http://source.apidesign.org/hg/bck2brwsr/rev/5e13b1ac2886 InheritanceA and InheritanceB classes]) the [[Bck2Brwsr]] needed to create accessor method to access each field in its declaring class. The accessor which prefixes the name of the field with "_" (forming a name that can't clash with mangled method names). The proper way to access field ''value'' defined in String class would then be:
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	which does the same in most cases. Only when there is a subclass defining its own field ''value'', the result would not be correct. Thus this kind of usage is appropriate when one knows the class is final and can't be subclassed (another reason to follow the [[ClientAPI]] advice).		which does the same in most cases. Only when there is a subclass defining its own field ''value'', the result would not be correct. Thus this kind of usage is appropriate when one knows the class is final and can't be subclassed (another reason to follow the [[ClientAPI]] advice).
		+
		+	=== Accessing a Static Field ===
		+
		+	Static fields are wrapped by accessors as well. However accessing them is simpler as they don't need proper '''this''' argument. One can use:
		+
		+	<source lang="javascript">
		+	var getValue = vm.java_lang_String(true)._CASE_INSENSITIVE_ORDER();
		+	var newValue = "...";
		+	vm.java_lang_String(true)._CASE_INSENSITIVE_ORDER(newValue);
		+	</source>

	== Possible Future Work ==		== Possible Future Work ==

JaroslavTulach: /* Possible Future Work */

2013-01-27T07:11:09Z

Possible Future Work

←Older revision		Revision as of 07:11, 27 January 2013
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	== Possible Future Work ==		== Possible Future Work ==

-	There is an experimental branch which replaces well known object types with a single letter:	+	There is an [http://source.apidesign.org/hg/bck2brwsr/rev/TypeNickNames experimental branch] which replaces well known object types with a single letter:
	* "Ljava_lang_String_2" would become 's'		* "Ljava_lang_String_2" would become 's'
	* "Ljava_lang_Object_2" would become 'o'		* "Ljava_lang_Object_2" would become 'o'
	Applying this pattern would shorten the generated [[JavaScript]] code. The experiments done so far, however have not yield too convincing results.		Applying this pattern would shorten the generated [[JavaScript]] code. The experiments done so far, however have not yield too convincing results.

JaroslavTulach: /* Accessing a Field */

2013-01-27T07:09:19Z

Accessing a Field

←Older revision		Revision as of 07:09, 27 January 2013
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	=== Accessing a Field ===		=== Accessing a Field ===

-	To support subclasses defining the same field (like in case of [http://source.apidesign.org/hg/bck2brwsr/rev/5e13b1ac2886 InheritanceA and InheritanceB classes]) the [[Bck2Brwsr]] needed to create accessor method to access each field which prefixes the name of the field with "_". The proper way to access field ''value'' defined in String class would then be:	+	To support subclasses defining the same field (like in case of [http://source.apidesign.org/hg/bck2brwsr/rev/5e13b1ac2886 InheritanceA and InheritanceB classes]) the [[Bck2Brwsr]] needed to create accessor method to access each field in its declaring class. The accessor which prefixes the name of the field with "_" (forming a name that can't clash with mangled method names). The proper way to access field ''value'' defined in String class would then be:

	<source lang="javascript">		<source lang="javascript">
Line 55:		Line 55:
	</source>		</source>

-	which does the same in most ~~of case~~. Only when there is a subclass defining its own field ''value'', the result would not be correct. Thus this kind of usage is appropriate when one knows the class is final and can't be subclassed.	+	which does the same in most cases. Only when there is a subclass defining its own field ''value'', the result would not be correct. Thus this kind of usage is appropriate when one knows the class is final and can't be subclassed (another reason to follow the [[ClientAPI]] advice).
		+
		+	== Possible Future Work ==
		+
		+	There is an experimental branch which replaces well known object types with a single letter:
		+	* "Ljava_lang_String_2" would become 's'
		+	* "Ljava_lang_Object_2" would become 'o'
		+	Applying this pattern would shorten the generated [[JavaScript]] code. The experiments done so far, however have not yield too convincing results.

JaroslavTulach: /* Fully Qualified Names */

2013-01-27T06:59:38Z

Fully Qualified Names

←Older revision		Revision as of 06:59, 27 January 2013
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	=== Fully Qualified Names ===		=== Fully Qualified Names ===

-	Fully qualified name uses '_' to separate package names and class name. The global virtual machine object '''vm''' has methods to obtain all classes. One can get reference to '''String''' as:	+	Fully qualified name uses '_' to separate package names and class name. The global virtual machine object '''vm''' has methods to obtain all (once referenced) classes. One can get reference to '''String''' as:

	<source lang="javascript">		<source lang="javascript">

JaroslavTulach: /* Like JNI */

2013-01-27T06:58:51Z

Like JNI

←Older revision		Revision as of 06:58, 27 January 2013
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	== Like [[JNI]] ==		== Like [[JNI]] ==

-	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]]. The [[Bck2Brwsr]] projects mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible. The mangling is based on ''underscore encoding'' substitution.	+	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]]. The [[Bck2Brwsr]] projects mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible and extends it only when the [[JVM]] compatibility differs from [[Java]] source compatibility and requires different treatment. The mangling is based on ''underscore encoding'' substitution.

	=== Fully Qualified Names ===		=== Fully Qualified Names ===

JaroslavTulach: /* Like JNI */

2013-01-27T06:57:57Z

Like JNI

←Older revision		Revision as of 06:57, 27 January 2013
Line 3:		Line 3:
	== Like [[JNI]] ==		== Like [[JNI]] ==

-	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]] ~~and~~ [[Bck2Brwsr]] mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible. The mangling is based on ''underscore encoding'' substitution.	+	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]]. The [[Bck2Brwsr]] projects mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible. The mangling is based on ''underscore encoding'' substitution.

	=== Fully Qualified Names ===		=== Fully Qualified Names ===

JaroslavTulach at 06:56, 27 January 2013

2013-01-27T06:56:57Z

←Older revision		Revision as of 06:56, 27 January 2013
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-	When translating the [[ByteCode]] to [[JavaScript]] the [[Bck2Brwsr]] project needs to face a common problem ~~-- when~~ translating a typed language (like [[Java]]) to untyped (like [[JavaScript]]) one needs to mange the names, so ~~they continue~~ to ~~support~~ method and field overloading.	+	When translating the [[ByteCode]] to [[JavaScript]] the [[Bck2Brwsr]] project needs to face a common problem. One needs to find [[Good Name]] for meaningful objects in the old world (aka. [[Java]]) inside the new world (in this case [[JavaScript]]). This happens whenever one is translating a typed language (like [[Java]] or [[C++]]) to untyped (like [[JavaScript]] and [[C]]) one needs to mange the names, so the new names still allow to express method and field overloading.

	== Like [[JNI]] ==		== Like [[JNI]] ==

JaroslavTulach: /* Static Method */

2013-01-26T18:43:09Z

Static Method

←Older revision		Revision as of 18:43, 26 January 2013
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	var r = clazz.valueOf__Ljava_lang_String_2I(10);		var r = clazz.valueOf__Ljava_lang_String_2I(10);
	</source>		</source>
		+
		+	=== Accessing a Field ===
		+
		+	To support subclasses defining the same field (like in case of [http://source.apidesign.org/hg/bck2brwsr/rev/5e13b1ac2886 InheritanceA and InheritanceB classes]) the [[Bck2Brwsr]] needed to create accessor method to access each field which prefixes the name of the field with "_". The proper way to access field ''value'' defined in String class would then be:
		+
		+	<source lang="javascript">
		+	var getValue = vm.java_lang_String(true)._value.call(this);
		+	var newValue = "...";
		+	vm.java_lang_String(true)._value.call(this, newValue);
		+	</source>
		+
		+	This can often be simplified to:
		+
		+	<source lang="javascript">
		+	var getValue = this._value();
		+	var newValue = "...";
		+	this._value(newValue);
		+	</source>
		+
		+	which does the same in most of case. Only when there is a subclass defining its own field ''value'', the result would not be correct. Thus this kind of usage is appropriate when one knows the class is final and can't be subclassed.

JaroslavTulach: /* Like JNI */

2013-01-26T18:33:38Z

Like JNI

←Older revision		Revision as of 18:33, 26 January 2013
Line 3:		Line 3:
	== Like [[JNI]] ==		== Like [[JNI]] ==

-	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]] and [[Bck2Brwsr]] mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible. The mangling is based on ''underscore encoding'' substitution:	+	There is a common [[wikipedia:Name_mangling\|mangling scheme]] specified by [[JNI]] for [[C]] and [[Bck2Brwsr]] mimics the [http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/design.html specification] as closely as possible. The mangling is based on ''underscore encoding'' substitution.
		+
		+	=== Fully Qualified Names ===
		+
		+	Fully qualified name uses '_' to separate package names and class name. The global virtual machine object '''vm''' has methods to obtain all classes. One can get reference to '''String''' as:
		+
		+	<source lang="javascript">
		+	var clazz = vm.java_lang_String(false);
		+	</source>
		+
		+	=== Methods ===

-	* Fully qualified name uses '_' to separate package names and class name
	* There is "__" after name of a method and before its arguments		* There is "__" after name of a method and before its arguments
	* return type is encoded first, parameters follow		* return type is encoded first, parameters follow
-	* If there is an '_' in the name segment, it gets replaced by "_1"	+	* If there is an '_' in the name or argument segment, it gets replaced by "_1"
	* array signatures start with '[' - such character is replaced by "_3"		* array signatures start with '[' - such character is replaced by "_3"
	* object signatures end with ';' - that character is replaced by "_2"		* object signatures end with ';' - that character is replaced by "_2"

-	As a result to call method String.substring(int, int) ~~returning String would~~ be written as:	+	As a result to call method ''String.substring(int, int)'' - e.g. a method that return string and takes two integers as arguments -it be written as:

	<source lang="javascript">		<source lang="javascript">
Line 18:		Line 27:
	var r = s.substring__Ljava_lang_String_2II(0, 5);		var r = s.substring__Ljava_lang_String_2II(0, 5);
	</source>		</source>
		+
		+	=== Static Method ===

	When calling a static method, one first needs to obtain the name of a class. The class is made available in a global object called "vm". As such calling ''String.valueOf(10)'' is translated to:		When calling a static method, one first needs to obtain the name of a class. The class is made available in a global object called "vm". As such calling ''String.valueOf(10)'' is translated to:

JaroslavTulach at 13:24, 26 January 2013

2013-01-26T13:24:05Z

←Older revision		Revision as of 13:24, 26 January 2013
Line 15:		Line 15:

	<source lang="javascript">		<source lang="javascript">
-	var s = "...";	+	var s = "...";
-	var r = s.substring__Ljava_lang_String_2II(0, 5);	+	var r = s.substring__Ljava_lang_String_2II(0, 5);
	</source>		</source>

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	<source lang="javascript">		<source lang="javascript">
-	var clazz = vm.java_lang_String(false);	+	var clazz = vm.java_lang_String(false);
-	var r = clazz.valueOf__Ljava_lang_String_2I(10);	+	var r = clazz.valueOf__Ljava_lang_String_2I(10);
	</source>		</source>