V4 DB Record Instance Syntax - Revision history

MartyKraimer at 19:50, 2 November 2005

2005-11-02T19:50:07Z

← Older revision		Revision as of 19:50, 2 November 2005
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	2005-11-01 MRK		2005-11-02 MRK

	= Overview =		= Overview =
Line 277:		Line 277:
	=== Link Initializer ===		=== Link Initializer ===

	~~; '''Comment from ANJ'''~~
	: I do not like this syntax, which is verbose and requires the application developer to know the interface names supported by that particular field of the record type (DCTs can provide a menu to choose from, but for anyone who doesn't use a DCT this is not a nice thing to require users to get right).
	~~: The calcout example presented uses generic choice names which presumably are equivalent to the version 3 PV_LINK type, but the meaning of the link parameters for these is under debate.~~
	: The syntax for link fields should only need the user to learn a single choice name for each link type. There may be more link types and more choice names as a result, but the interface names themselves should not have to appear in DB files at all.
	~~: The mbbi example below uses my original and preferred syntax, which is shorter and more in keeping with the rest of the new DB file syntax.~~

	;''linkInitializer:''		;''linkInitializer:''
	: ''~~choice~~(choiceName) supportStructName'' <tt>{</tt> ''structAssignmentList'' <tt>}</tt>		: ''support(choiceName) supportStructName'' <tt>{</tt> ''structAssignmentList'' <tt>}</tt>

	;''choiceName:''		;''choiceName:''
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	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	block = true		block = true
	output = ~~choice~~(outputLink) ~~PvOutputLink~~{		output = support(outputLink) OutputLink{
	pvname = "fum:baz:heater";		pvname = "fum:baz:heater";
	process = true;		process = true;
Line 303:		Line 298:
	input = [2] {		input = [2] {
	{ link = {		{ link = {
	~~choice~~(monitorLink) ~~PvMonitorLink~~{		support(monitorLink) MonitorLink{
	pvname = "foo:temperature:setpoint";		pvname = "foo:temperature:setpoint";
	process = false		process = false
Line 311:		Line 306:
	{ block=true		{ block=true
	link = {		link = {
	~~choice~~(inputLink) ~~PvInputLink~~ {		support(inputLink) InputLink {
	pvname = "foo:temperature:sensor";		pvname = "foo:temperature:sensor";
	process = true;		process = true;
Line 325:		Line 320:

	mbbi foo:bar:door = {		mbbi foo:bar:door = {
	input = ~~choice~~(acro9440) VME{0, 5};		input = support(acro9440) VME{0, 5};
	...		...
	}		}

MartyKraimer at 20:48, 1 November 2005

2005-11-01T20:48:20Z

← Older revision		Revision as of 20:48, 1 November 2005
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	2005-10-~~19 ANJ~~		2005-11-01 MRK

	= Overview =		= Overview =
Line 8:		Line 8:
	A complete redesign of the syntax has been done to help improve parsing, and to provide commonality between the syntax of a DB file and the string representation of structured data values passed through Channel Access.		A complete redesign of the syntax has been done to help improve parsing, and to provide commonality between the syntax of a DB file and the string representation of structured data values passed through Channel Access.

			<b>NOTE:</b> See the note at the beginning of the "V4 DBD Statement Syntax"
			concerning the syntax for link and struct fields.

	= Document Conventions =		= Document Conventions =
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	;''linkInitializer:''		;''linkInitializer:''
	: ''choiceName'' <tt>~~(</tt> ''interfaceName'' <tt>)~~ {</tt> ''structAssignmentList'' <tt>}</tt>		: ''choice(choiceName) supportStructName'' <tt>{</tt> ''structAssignmentList'' <tt>}</tt>

	;''choiceName:''		;''choiceName:''
	: ''identifier''		: ''identifier''

	;''~~interfaceName~~:''		;''supportStructName:''
	: ''identifier''		: ''identifier''

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	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	output = outputLink~~(LinkFloat64~~) {		block = true
			output = choice(outputLink) PvOutputLink{
	pvname = "fum:baz:heater";		pvname = "fum:baz:heater";
	process = true;		process = true;
	wait = true;		wait = true;
	~~block = true;~~
	}		}
	input = [2] {		input = [2] {
	{link = {		{ link = {
	monitorLink~~(LinkFloat64~~) {		choice(monitorLink) PvMonitorLink{
	pvname = "foo:temperature:setpoint";		pvname = "foo:temperature:setpoint";
	process = false		process = false
			}
	}		}
	}		}
	{link = {		{ block=true
	inputLink~~(LinkFloat64~~) {		link = {
	pvname = "foo:temperature:sensor";		choice(inputLink) PvInputLink {
	process = true;		pvname = "foo:temperature:sensor";
	wait = true;		process = true;
	~~block~~ = true;		wait = true;
	~~inheritSeverity = true~~		inheritSeverity = true
	}		}
			}
	}		}
	};		};
Line 321:		Line 325:

	mbbi foo:bar:door = {		mbbi foo:bar:door = {
	input = acro9440(0, 5);		input = choice(acro9440) VME{0, 5};
	...		...
	}		}

			<b>QUESTION</b> There is nothing that allows a DVT to prompt a user
			with a valid set if support for a particular link. Should there be?

	=== Array Initializers ===		=== Array Initializers ===

AndrewJohnson: Comment on new Link Initializer syntax

2005-10-19T22:37:25Z

Comment on new Link Initializer syntax

← Older revision		Revision as of 22:37, 19 October 2005
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	~~Record Instance Syntax Sept 30~~ 2005		2005-10-19 ANJ

	= Overview =		= Overview =

Line 273:		Line 274:

	=== Link Initializer ===		=== Link Initializer ===

			; '''Comment from ANJ'''
			: I do not like this syntax, which is verbose and requires the application developer to know the interface names supported by that particular field of the record type (DCTs can provide a menu to choose from, but for anyone who doesn't use a DCT this is not a nice thing to require users to get right).
			: The calcout example presented uses generic choice names which presumably are equivalent to the version 3 PV_LINK type, but the meaning of the link parameters for these is under debate.
			: The syntax for link fields should only need the user to learn a single choice name for each link type. There may be more link types and more choice names as a result, but the interface names themselves should not have to appear in DB files at all.
			: The mbbi example below uses my original and preferred syntax, which is shorter and more in keeping with the rest of the new DB file syntax.

	;''linkInitializer:''		;''linkInitializer:''
	: ''choiceName(interfaceName)'' <tt>{</tt> ''structAssignmentList'' <tt>}</tt>		: ''choiceName'' <tt>(</tt> ''interfaceName'' <tt>) {</tt> ''structAssignmentList'' <tt>}</tt>

	;''choiceName:''		;''choiceName:''
Line 286:		Line 293:

	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	output = outputLink(LinkFloat64){		output = outputLink(LinkFloat64) {
	pvname = "fum:baz:heater";		pvname = "fum:baz:heater";
	process = true;		process = true;
Line 294:		Line 301:
	input = [2] {		input = [2] {
	{link = {		{link = {
	monitorLink(LinkFloat64){		monitorLink(LinkFloat64) {
	pvname = "foo:temperature:setpoint";		pvname = "foo:temperature:setpoint";
	process = false		process = false
Line 300:		Line 307:
	}		}
	{link = {		{link = {
	inputLink(LinkFloat64){		inputLink(LinkFloat64) {
	pvname = "foo:temperature:sensor";		pvname = "foo:temperature:sensor";
	process = true;		process = true;
Line 309:		Line 316:
	}		}
	};		};
	expression = "(~~setpoint~~ - ~~current~~) > 0";		expression = "(B - A) > 0";
	...		...
	}		}

MartyKraimer: Change link syntax

2005-09-30T15:14:04Z

Change link syntax

← Older revision		Revision as of 15:14, 30 September 2005
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	Record Instance Syntax Sept 27 2005		Record Instance Syntax Sept 30 2005
	= Overview =		= Overview =

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	;''linkInitializer:''		;''linkInitializer:''
	: ''choiceName'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>		: ''choiceName(interfaceName)'' <tt>{</tt> ''structAssignmentList'' <tt>}</tt>

	;''choiceName:''		;''choiceName:''
	: ''identifier''		: ''identifier''

	These select a particular link support for the field, and set its address according to the structure type defined for that link type.		;''interfaceName:''
			: ''identifier''

			These select a particular link support and interface for the field, and set its address according to the structure type defined for that link type.

	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	output = ~~outputLinkFloat64~~(		output = outputLink(LinkFloat64){
	pvname = "fum:baz:heater";		pvname = "fum:baz:heater";
	process = true;		process = true;
	wait = true;		wait = true;
	block = true;		block = true;
	)		}
	input = [2] {		input = [2] {
	{link = {		{link = {
	~~monitorLinkFloat64~~{		monitorLink(LinkFloat64){
	pvname = "foo:temperature:setpoint";		pvname = "foo:temperature:setpoint";
	process = false		process = false
Line 297:		Line 300:
	}		}
	{link = {		{link = {
	~~inputLinkFloat64~~{		inputLink(LinkFloat64){
	pvname = "foo:temperature:sensor";		pvname = "foo:temperature:sensor";
	process = true;		process = true;

MartyKraimer at 15:18, 27 September 2005

2005-09-27T15:18:51Z

← Older revision		Revision as of 15:18, 27 September 2005
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	Record Instance Syntax Sept 22 2005		Record Instance Syntax Sept 27 2005
	= Overview =		= Overview =


	The syntax used for record instances has to change in EPICS V4, since we now have to support structured data. ~~While it would have been possible to modify the V3 syntax to allow for this, a~~ complete redesign of the syntax has been done to help improve parsing, and to provide commonality between the syntax of a DB file and the string representation of structured data values passed through Channel Access.		The syntax used for record instances has to change in EPICS V4,
			since we now have to support structured data.
			A complete redesign of the syntax has been done to help improve parsing, and to provide commonality between the syntax of a DB file and the string representation of structured data values passed through Channel Access.


Line 217:		Line 219:
	: ''structInitializer''		: ''structInitializer''
	: ''arrayInitializer''		: ''arrayInitializer''
	: ''~~devlinkInitializer~~''		: ''linkInitializer''

	;''initializerList:''		;''initializerList:''
Line 270:		Line 272:
	}		}

	=== Link ~~and Device Initializers~~ ===		=== Link Initializer ===

	;''~~devlinkInitializer~~:''		;''linkInitializer:''
	: ''choiceName'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>		: ''choiceName'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>

Line 278:		Line 280:
	: ''identifier''		: ''identifier''

	These select a particular link ~~or device~~ support for the field, and set its address according to the structure type defined for that link ~~or device~~ type.		These select a particular link support for the field, and set its address according to the structure type defined for that link type.

	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	output = ca("fum:baz:heater"; pp=y);		output = outputLinkFloat64(
			pvname = "fum:baz:heater";
			process = true;
			wait = true;
			block = true;
			)
	input = [2] {		input = [2] {
	{link = {		{link = {
	~~MonitorLink~~{		monitorLinkFloat64{
	pvname = "foo:temperature:setpoint";		pvname = "foo:temperature:setpoint";
	process = false		process = false
Line 290:		Line 297:
	}		}
	{link = {		{link = {
	~~InputLink~~{		inputLinkFloat64{
	pvname = "foo:temperature:sensor";		pvname = "foo:temperature:sensor";
	process = true;		process = true;
			wait = true;
			block = true;
	inheritSeverity = true		inheritSeverity = true
	}		}

MartyKraimer at 13:05, 22 September 2005

2005-09-22T13:05:13Z

← Older revision		Revision as of 13:05, 22 September 2005
Line 1:		Line 1:
	Record Instance Syntax Sept 16 2005		Record Instance Syntax Sept 22 2005
	= Overview =		= Overview =

Line 282:		Line 282:
	calcout foo:temperature:controller = {		calcout foo:temperature:controller = {
	output = ca("fum:baz:heater"; pp=y);		output = ca("fum:baz:heater"; pp=y);
	~~inputs~~ = [2] {		input = [2] {
	{ ~~"setpoint", pv(~~"foo:temperature:setpoint") }		{link = {
	{ ~~"current", db(~~"foo:temperature:sensor"; ms=y) }		MonitorLink{
			pvname = "foo:temperature:setpoint";
			process = false
			}
			}
			{link = {
			InputLink{
			pvname = "foo:temperature:sensor";
			process = true;
			inheritSeverity = true
			}
			}
	};		};
	expression = "(setpoint - current) > 0";		expression = "(setpoint - current) > 0";

MartyKraimer at 15:32, 16 September 2005

2005-09-16T15:32:01Z

← Older revision		Revision as of 15:32, 16 September 2005
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	: The information on this page should now be reasonably stable, although it's not yet complete (the definition of ''extraFieldAssignment'' given towards the end still needs fleshing out, but I don't see that as a high priority right now and it doesn't affect anything else defined here).		Record Instance Syntax Sept 16 2005
	~~: Andrew Johnson, 2005-05-25~~		= Overview =


Line 27:		Line 27:
	;''integerConstant:''		;''integerConstant:''
	: ''positiveInteger''		: ''positiveInteger''
	~~: <tt>-</tt> ''positiveInteger''~~

	;''positiveInteger:''		;''positiveInteger:''
Line 245:		Line 244:
	}		}

	'''Q: What about map fields? For record initialization we could parse these like an array of structures, where the first structure element is the key and the second is the value. However being able to access and modify elements of a map over CA may be harder, and needs some thought.'''

	=== Structure Initializers ===		=== Structure Initializers ===
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	;''devlinkInitializer:''		;''devlinkInitializer:''
	: ''~~linkType'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>~~		: ''choiceName'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>
	~~: ''deviceType~~'' <tt>(</tt> ''structAssignmentList'' <tt>)</tt>

	;''~~linkType:''~~		;''choiceName:''
	~~: ''identifier''~~

	~~;''deviceType~~:''
	: ''identifier''		: ''identifier''

Line 338:		Line 332:
	value = float32 [3,3] { {1}, {[1] = 1}, {[2] = 1}};		value = float32 [3,3] { {1}, {[1] = 1}, {[2] = 1}};
	}		}

	~~== Extra Fields ==~~

	'''I don't like the idea of adding fields to record types, it feels like making it possible to add a sail to a sports car (I think there are better ways to provide the desired extensibility), so I haven't completed this syntax yet - Andrew'''

	~~;''extraFieldAssigment:''~~
	~~: <tt>new</tt> ''extraField'' <tt>=</tt> ''extraInitializer'' <tt>;</tt>~~

	~~This syntax not fully developed yet...~~

	~~Information needed includes:~~

	* fieldName
	* extension interface name
	* configuration data

	~~Things to think about here:~~
	* Make sure the syntax doesn't make a misspelled ''fieldName'' in a ''fieldAssignment'' look like an ''extraFieldAssignment'' and thereby cause a misleading error message to be printed.
	* Is any part of the new field writable through CA?
	* If so, how much if it can be changed? Presumably just the configuration data.
	* Can I delete an extraField, or change it to a different type of extension?

AndrewJohnson: /* Extra Fields */

2005-07-07T20:00:30Z

Extra Fields

← Older revision		Revision as of 20:00, 7 July 2005
Line 340:		Line 340:

	== Extra Fields ==		== Extra Fields ==

			'''I don't like the idea of adding fields to record types, it feels like making it possible to add a sail to a sports car (I think there are better ways to provide the desired extensibility), so I haven't completed this syntax yet - Andrew'''

	;''extraFieldAssigment:''		;''extraFieldAssigment:''

AndrewJohnson: /* Database File */

2005-05-27T19:15:34Z

Database File

← Older revision		Revision as of 19:15, 27 May 2005
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	= Database File =		= Database File =

	~~I need to~~ define ~~these, which are really preprocessor objects~~:		This section will eventually define what can appear in a .db file. That currently means:

			* record instances
	* comments		* comments
	* substitution ~~macros~~		* macro instances, including where they will be allowed
	* ~~templates and ports~~		* template files and substitution macro definitions
			* port definitions for template instances
			* data for tools such as VDCT, that will not be discarded by .db processing tools.

			The templates, macros and ports design should be very similar to the ideas produced for R3.14 VDCT templates.

	= Record Definitions =		= Record Definitions =

AndrewJohnson at 22:32, 25 May 2005

2005-05-25T22:32:00Z

← Older revision		Revision as of 22:32, 25 May 2005
Line 1:		Line 1:
	: '''~~This page~~ still ~~being worked on...'~~''		: The information on this page should now be reasonably stable, although it's not yet complete (the definition of ''extraFieldAssignment'' given towards the end still needs fleshing out, but I don't see that as a high priority right now and it doesn't affect anything else defined here).
			: Andrew Johnson, 2005-05-25