Improving the /Z flag of Wave, NVAR, SVAR

Share icon

Note: I'm always coding with "NVAR SVAR WAVE checking" turned on and rtGlobals=3

1.) Currently the /Z of the above operations doesn't recognize dfrefs which are null and are supplied by /SDFR.
For example the following is my current way in referencing global vars in some of my procedures.

	if(!DataFolderExists(settingsFolder))
		print "BUG: settings folder does not exist"
		return 0
	endif
	
	NVAR/Z/SDFR=$settingsFolder scrapFormatOne, scrapFormatTwo, hddFormatOne, hddFormatTwo, exportLowRes, exportHighRes
	
	if(!NVAR_Exists(scrapFormatOne) || !NVAR_Exists(scrapFormatTwo) || !NVAR_Exists(hddFormatOne) || !NVAR_Exists(hddFormatTwo) || !NVAR_Exists(exportLowRes) || !NVAR_Exists(exportHighRes))
		print "BUG: some nvars are missing"
		return 0
	endif

I always have to check that the datafolder exists before I pass it to the /SDFR flag. In my eyes the /Z flag should also prevent run time errors due to invalid /null dfrefs in the /SDFR flag.
The following example shows hopefully what I mean:

#pragma rtGlobals=3		// Use modern global access method.
Function doTest()

	string folder="root:testing"
	string folderNonExistent="root:testingNonExistent"

	NewDataFolder/O $folder
	dfref folderDFR = $folder
	dfref folderNonExistentDFR = $folderNonExistent

	variable/G folderDFR:nvarOne
	variable/G folderDFR:nvarTwo
	variable/G folderDFR:nvarThree
	variable/G folderDFR:nvarFour
	variable/G folderDFR:nVarFive	

	NVAR/Z nvarOne = $(folder) +":nvarOne"

	if(NVar_Exists(nvarOne))
		print "nvarOne exists"
	endif

	NVAR/Z nvarTwo = $(folderNonExistent) +":nvarTwo"

	if(NVar_Exists(nvarTwo))
		print "nvarTwo exists"
	endif

	NVAR/Z/SDFR=folderDFR nVarThree 

	if(NVar_Exists(nVarThree))
		print "nVarThree exists"
	endif

	NVAR/Z/SDFR=folderNonExistentDFR nVarFour // <- runtime error

	if(NVar_Exists(nVarFour))
		print "nVarFour exists"
	endif
	
	KilLDataFolder/Z $folder
	
	// now the dfref is still valid but the folder is non existent
	NVAR/Z/SDFR=folderDFR nVarFive	// no run time error, /Z works as expected

	if(NVar_Exists(nVarFive))
		print "nVarFive exists"
	endif
End



2.) It would be also terrific if there would be an easier way to get to know if the last NVAR/SVAR/Wave call with the /Z flag was completely successfull or not.
The idea would be along the lines of


         NVAR/Z/SDFR=$settingsFolder scrapFormatOne, scrapFormatTwo, hddFormatOne, hddFormatTwo, exportLowRes, exportHighRes
         if(!lastRefSuccess()) // or a V_flag
		print "BUG: some nvars are missing"
		return 0
	endif


Thanks for reading,
Thomas