You say you use TeXStudio while TeXStudio is editing software for creating and maintaining .tex-source-files. You wish to have a macro for maintaining unique ids in terms of
So the question arises:
Do you wish the macro to be an editor-macro which is part of your configuration of TeXStudio and which is available when operating the software TeXStudio?
Do you wish the macro to be a macro from the (La)TeX-programming-language which will be carried out when the LaTeX-compiler is compiling your .tex-files?
Let's abstract the problem:
The single instances of the
note-environment form records of a database maintained in terms of your .tex-source-files.
You wish a mechanism for automatically obtaining primary keys (unique identifiers) for these records so records of the database can be identified by means of these primary keys.
Basically there are (at least) two possibilities for dealing with primary keys/unique ids in databases:
Either with each record of the database some of its elements can be combined in a way in which the combination of these elements already forms a unique primary key which can be used for deriving the record's unique identifier.
Sometimes this is possible. Often this is not possible.
A variation of possibility 1 can be that the whole record itself forms a primary key calculable by taking the set of characters that forms the record and calculating some hash-value by means of a perfect hash-function.
With possibility 1 the primary key/the unique identifier of a record of the database changes as soon as some of those components of the record get changed from which the primary key/unique identifier is derived.
Seems at some stage the .tex-input-files are not to be processed by whatsoever LaTeX compiler but by the software "LaTeX Note Importer for Anki". I doubt that the "infrastructure" provided by the software "LaTeX Note Importer for Anki" is suitable for post-processing the content of
note-environments in a way where it is possible to extract pieces of data in order to somehow derive primary keys/unique ids from them.
Therefore seems possibility 1 is not really an option.
Or each record of the database needs to have an element for storing the record's unique ID, which is to be generated somehow. E.g., by counting records or (in case of not creating two records at the same time) by using some sort of time-stamp from the moment of creating the record, or whatever. Then this generated element is the primary key for identifying the record. In this case this element is a component of the database and thus needs to be stored as such.
Adding a primary-key-element to a database-entry/record and permanently storing it requires modifying the set of files which makes up the database in question.
Database-management programs like MySQL, MariaDB or Microsoft Access are designed for automatically generating and maintaining primary keys/unique identifiers and modifying database-files=the source-files that form the database in question for storing these primary keys.
As you use .tex-source-files for maintaining your database-records/your database-entries in terms of
note-environments, you need mechanisms for creating primary keys/unique ids and for changing/editing those of your .tex-source-files that make up your
note-database in order to store these primary keys/unique ids.
One mechanism could be formed by you and your favourite .tex editor when you type the unique id belonging to an instance of the
note-environment yourself. ;-)
Probably this can be automatized by implementing some editor-macros for TeXStudio (not macros in the programming language TeX/LaTeX) for creating/maintaining unique-ids and inserting
note-environments with these unique-ids into your .tex-source-files automatically.
I seldom use TeXStudio.
In case it is ensured that only one
note-environment is generated at a time, I recommend following frougon's suggestion of using time-stamps of that moment when the instance of the
note-environment is inserted into the .tex-source-file. (For the sake of readability that time-stamp can probably be in some ISO8601-format).
I suggest implementing a TeXStudio-editor-macro which inserts an instance of the
note-environment into your .tex-source-file where the
\xplain-command is of pattern:
If the unique id is formed from a time-stamp of the moment when the instance of the
note-environment gets inserted into your .tex-source-file, you don't need to maintain lists of unique-ids.
But you need to ensure that the clock of your system works correctly whenever having TeXStudio insert another instance of the
In case such time-stamps for some reason are not suitable as unique-ids:
In the past I used WinEdt. Back then WinEdt had nice editor-macros for maintaining referencing labels by parsing .tex-input-files and displaying a list with the referencing-labels that can be found as arguments of
\label-commands. Back then the mechanism was not perfect as referencing-labels coming from other files via
\externaldocument were not taken into consideration.
Probably a similar feature exists in TeXStudio and can be adapted to
\xplain-commands instead of
\label-commands and can be enhanced to suggest new strings which are not already in the list.