Signature - Revision history

Kevin Reid: finish subst

2011-08-27T00:18:32Z

finish subst

New page

A [[Signature]] describes the protocol of another object.

This type is proposed to replace [[TypeDesc]], [[MessageDesc]], and [[ParamDesc]]; the motivation for doing so is that while TypeDesc allows for message parameters' [[guard]]s to be presented, it is difficult to define the means for doing so as a [[miranda method]]; Signature is defined so as to simplify this. Furthermore, it is arguably "fewer moving parts" in that rather than having the TD/MD/PD structure imitating a subset of what Kernel-E can express, we use Kernel-E directly.

(REVIEW: Should we adopt Signature in place of TypeDesc?)

(REVIEW: What should the expansion of the nonkernel "interface" expression be, given that we eliminate MessageDesc and ParamDesc which it uses? -- MarkM suggests expanding to an ObjectExpr which is asked for its alleged type, and then twiddling it further.)

(XXX Define the [[Miranda __getAllegedType/0]] behavior under this system precisely.)

(XXX [[User:Kevin Reid]] needs to review the experimental code and add other design decision questions to this page.)

== State ==

* <code>objectExpr</code> :[[ObjectExpr]]
* <code>env</code> :[[Env]]
* <code>supers</code> :[[List]]<nowiki>[</nowiki>[[Signature]]]
* <code>mirandaSignature</code> :[[Signature]]

The most important fields of a signature are the ''object expr'' and ''env''.

The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except redacted: the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing|GBA]]) and <code>implements</code> clauses) have been eliminated.

The environment field contains an [[Env]] with bindings for every free noun in the redacted version of the object expr. (These will mostly be guards.)

(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))

The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols, or multiple inheritance in objects implemented in languages providing such. The significance of the ordering of the list is left to the generator of the signature.

The miranda signature field holds a signature containing the miranda protocol in use by the E implementation hosting the object whose signature this is. This is the means provided for E programs to see the miranda protocol, and it replaces TypeDesc's approach of including the miranda MessageDescs in every __getAllegedType TypeDesc. It also might be used to detect un-translated mismatches between E system versions.

(NOTE: A planned extension is to allow type-parameterized protocols. This will be done by allowing nouns not bound in the env, but bound by a parameter list instead. Such a signature responds to get/N returning a concrete protocol.)

== Maker protocol ==

(XXX there is no way to specify the mirandaSignature.)

=== asType/0 ===
{{asType|Signature}}

{{maker msgdoc|run|2|objectExpr :[[ObjectExpr]], env :[[Env]]|[[Signature]]}}

As run/3 but with the supers field being <code>[]</code>.

{{maker msgdoc|run|3|objectExpr :[[ObjectExpr]], env :[[Env]], supers :[[List]]<nowiki>[</nowiki>[[Signature]]]|[[Signature]]}}

{{unspecified message}}

== Protocol ==

{{instance msgdoc|getObjectExpr|0||[[ObjectExpr]]}}

Accessor; see state description.

{{instance msgdoc|getEnv|0||[[Env]]}}

Accessor; see state description.

{{instance msgdoc|getMirandaSignature|0||[[Signature]]}}

Accessor; see state description.

{{instance msgdoc|getSupers|0||[[List]]<nowiki>[</nowiki>[[Signature]]]}}

Accessor; see state description.

{{instance msgdoc|getFQName|0||[[String]]}}

Returns the [[fully-qualified name]] constructed from the environment's FQN prefix and the object expr's pattern.

(XXX Define the method of construction.)

[[Category:ELib specification]]
[[Category:Unresolved design issues]]

Kevin Reid: /* State */ s/Scope/Env/

2011-08-27T00:17:34Z

State: s/Scope/Env/

←Older revision		Revision as of 00:17, 27 August 2011
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	* <code>objectExpr</code> :[[ObjectExpr]]		* <code>objectExpr</code> :[[ObjectExpr]]
-	* <code>env</code> :[[~~Scope~~]]	+	* <code>env</code> :[[Env]]
	* <code>supers</code> :[[List]]<nowiki>[</nowiki>[[Signature]]]		* <code>supers</code> :[[List]]<nowiki>[</nowiki>[[Signature]]]
	* <code>mirandaSignature</code> :[[Signature]]		* <code>mirandaSignature</code> :[[Signature]]
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	The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except redacted: the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing\|GBA]]) and <code>implements</code> clauses) have been eliminated.		The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except redacted: the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing\|GBA]]) and <code>implements</code> clauses) have been eliminated.

-	The environment field contains a [[~~Scope~~]] with bindings for every free noun in the redacted version of the object expr. (These will mostly be guards.)	+	The environment field contains an [[Env]] with bindings for every free noun in the redacted version of the object expr. (These will mostly be guards.)

	(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))		(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))

Kevin Reid: Reverted edits by 195.229.181.250 (Talk); changed back to last version by Kevin Reid

2011-04-20T18:45:10Z

Reverted edits by 195.229.181.250 (Talk); changed back to last version by Kevin Reid

←Older revision		Revision as of 18:45, 20 April 2011
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	(XXX there is no way to specify the mirandaSignature.)		(XXX there is no way to specify the mirandaSignature.)

-	~~YMMD~~ with ~~that awnesr! TX~~	+	=== asType/0 ===
		+	{{asType\|Signature}}
		+
		+	{{maker msgdoc\|run\|2\|objectExpr :[[ObjectExpr]], env :[[Scope]]\|[[Signature]]}}
		+
		+	As run/3 but with the supers field being <code>[]</code>.
		+
		+	{{maker msgdoc\|run\|3\|objectExpr :[[ObjectExpr]], env :[[Scope]], supers :[[List]]<nowiki>[</nowiki>[[Signature]]]\|[[Signature]]}}
		+
		+	{{unspecified message}}

	== Protocol ==		== Protocol ==

195.229.181.250: /* asType/0 */

2011-04-20T12:46:02Z

asType/0

←Older revision		Revision as of 12:46, 20 April 2011
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	(XXX there is no way to specify the mirandaSignature.)		(XXX there is no way to specify the mirandaSignature.)

-	~~=== asType/0 ===~~	+	YMMD with that awnesr! TX
-	~~{{asType\|Signature}}~~	+
-		+
-	~~{{maker msgdoc\|run\|2\|objectExpr :[[ObjectExpr]], env :[[Scope]]\|[[Signature]]}}~~	+
-		+
-	~~As run/3 but~~ with ~~the supers field being <code>[]</code>.~~	+
-		+
-	~~{{maker msgdoc\|run\|3\|objectExpr :[[ObjectExpr]], env :[[Scope]], supers :[[List]]<nowiki>[</nowiki>[[Signature]]]\|[[Signature]]}}~~	+
-		+
-	~~{{unspecified message}}~~	+

	== Protocol ==		== Protocol ==

Kevin Reid: /* State */ clarify redaction for environment

2009-01-03T22:55:08Z

State: clarify redaction for environment

←Older revision		Revision as of 22:55, 3 January 2009
Line 20:		Line 20:
	The most important fields of a signature are the ''object expr'' and ''env''.		The most important fields of a signature are the ''object expr'' and ''env''.

-	The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except ~~that~~ the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing\|GBA]]) and <code>implements</code> clauses) have been eliminated.	+	The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except redacted: the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing\|GBA]]) and <code>implements</code> clauses) have been eliminated.

-	The environment field contains a [[Scope]] with bindings for every free noun in the object expr. (These will mostly be guards.)	+	The environment field contains a [[Scope]] with bindings for every free noun in the redacted version of the object expr. (These will mostly be guards.)

	(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))		(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))

Kevin Reid: /* State */ mention as clause

2009-01-03T22:45:33Z

State: mention as clause

←Older revision		Revision as of 22:45, 3 January 2009
Line 20:		Line 20:
	The most important fields of a signature are the ''object expr'' and ''env''.		The most important fields of a signature are the ''object expr'' and ''env''.

-	The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except that the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>implements</code> ~~clause~~) have been eliminated.	+	The object expr is the expression of the object which this is the signature of (or the closest approximation, if the object is not written in E), except that the method and matcher bodies have been replaced with UnspecifiedExpr, a new [[EExpr]] introduced for this purpose, and the auditors (<code>as</code> (if under [[Guard-based auditing\|GBA]]) and <code>implements</code> clauses) have been eliminated.

	The environment field contains a [[Scope]] with bindings for every free noun in the object expr. (These will mostly be guards.)		The environment field contains a [[Scope]] with bindings for every free noun in the object expr. (These will mostly be guards.)

Kevin Reid: further conclusions

2008-08-15T04:05:29Z

further conclusions

←Older revision		Revision as of 04:05, 15 August 2008
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	(REVIEW: Should we adopt Signature in place of TypeDesc?)		(REVIEW: Should we adopt Signature in place of TypeDesc?)

-	(REVIEW: What should the expansion of the nonkernel "interface" expression be, given that we eliminate MessageDesc and ParamDesc which it uses?)	+	(REVIEW: What should the expansion of the nonkernel "interface" expression be, given that we eliminate MessageDesc and ParamDesc which it uses? -- MarkM suggests expanding to an ObjectExpr which is asked for its alleged type, and then twiddling it further.)

	(XXX Define the [[Miranda __getAllegedType/0]] behavior under this system precisely.)		(XXX Define the [[Miranda __getAllegedType/0]] behavior under this system precisely.)
Line 26:		Line 26:
	(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))		(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))

-	The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols.	+	The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols, or multiple inheritance in objects implemented in languages providing such. The significance of the ordering of the list is left to the generator of the signature.

	The miranda signature field holds a signature containing the miranda protocol in use by the E implementation hosting the object whose signature this is. This is the means provided for E programs to see the miranda protocol, and it replaces TypeDesc's approach of including the miranda MessageDescs in every __getAllegedType TypeDesc. It also might be used to detect un-translated mismatches between E system versions.		The miranda signature field holds a signature containing the miranda protocol in use by the E implementation hosting the object whose signature this is. This is the means provided for E programs to see the miranda protocol, and it replaces TypeDesc's approach of including the miranda MessageDescs in every __getAllegedType TypeDesc. It also might be used to detect un-translated mismatches between E system versions.
Line 64:		Line 64:

	Accessor; see state description.		Accessor; see state description.
-
-	~~(REVIEW: Should this be a [[ConstSet]] instead of a [[ConstList]]?)~~

	{{instance msgdoc\|getFQName\|0\|\|[[String]]}}		{{instance msgdoc\|getFQName\|0\|\|[[String]]}}

Kevin Reid: getDocComment dies, getFQName lives

2008-08-15T03:10:59Z

getDocComment dies, getFQName lives

←Older revision		Revision as of 03:10, 15 August 2008
Line 72:		Line 72:

	(XXX Define the method of construction.)		(XXX Define the method of construction.)
-
-	~~(REVIEW: This was introduced for legacy compatibility; should it exist, be deprecated, or not exist?)~~
-
-	~~{{instance msgdoc\|getDocComment\|0\|\|[[nullOk]]<nowiki>[</nowiki>[[String]]]}}~~
-
-	~~Returns the object expr's docComment.~~
-
-	~~(REVIEW: This was introduced for legacy compatibility; should it exist, be deprecated, or not exist?)~~

	[[Category:ELib specification]]		[[Category:ELib specification]]
	[[Category:Unresolved design issues]]		[[Category:Unresolved design issues]]

Kevin Reid: add conclusion to exposure note

2008-08-15T03:00:16Z

add conclusion to exposure note

←Older revision		Revision as of 03:00, 15 August 2008
Line 24:		Line 24:
	The environment field contains a [[Scope]] with bindings for every free noun in the object expr. (These will mostly be guards.)		The environment field contains a [[Scope]] with bindings for every free noun in the object expr. (These will mostly be guards.)

-	(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects?)	+	(REVIEW: This proposal therefore exposes every object mentioned in a parameter list. Is this too hazardous? (MarkM feels that the simple rule of "everything between the braces is public" (i.e. from the { of the object to the { of a method) helps.) Are there practical ways to reduce the potential harm from mentioning authority-bearing objects? ([[User:Kevin Reid]],[[User:Markm]],[[User:dtribble]] have discussed this 2008-08-14 and decided that nothing need be done.))

	The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols.		The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols.

Kevin Reid: /* State */ explain mirandaSignature

2008-08-15T02:33:00Z

State: explain mirandaSignature

←Older revision		Revision as of 02:33, 15 August 2008
Line 27:		Line 27:

	The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols.		The supers field lists additional signatures of protocols which this object also implements, such as by <code>[[extends]]</code>, or explicit protocols.
		+
		+	The miranda signature field holds a signature containing the miranda protocol in use by the E implementation hosting the object whose signature this is. This is the means provided for E programs to see the miranda protocol, and it replaces TypeDesc's approach of including the miranda MessageDescs in every __getAllegedType TypeDesc. It also might be used to detect un-translated mismatches between E system versions.

	(NOTE: A planned extension is to allow type-parameterized protocols. This will be done by allowing nouns not bound in the env, but bound by a parameter list instead. Such a signature responds to get/N returning a concrete protocol.)		(NOTE: A planned extension is to allow type-parameterized protocols. This will be done by allowing nouns not bound in the env, but bound by a parameter list instead. Such a signature responds to get/N returning a concrete protocol.)