topic Re: What happend when using MBCS character as macro variable name? in SAS Programming

What happend when using MBCS character as macro variable name?

whymath — Mon, 20 Jan 2025 09:31:20 GMT

In a very unique situation, I see a guy's program and he use Chinese character as macro variable name, it supriesed me because I used to think the naming rules of macro variable is the same with dataset variable. But the code can really run without syntax error:

%let software=SAS;
%let 软件=SAS;            *Chinese;
%let ソフトウェア=SAS;    *Japenese;
%let 😀=SAS;              *Emoji;

Run the code in unicode supported enviroment(&sysencoding is utf-8), you will see the top 3 statements will be execute without error.

However, when try to print the values of these variables, more suprising things comming:

%put &=software;
SOFTWARE=SAS

%put &=软件;
软件

%put &=ソフトウェア;
ソフトウェア

When printing values whose name are MBCS characters, names rather than values are printted.

Checking sashelp.vmacro, 软件 and ソフトウェア are not found.

I ask this guy and know he use Chinese coded environment(&sysencoding is euc-cn), so I try the code in Chinese coded environment and result is different:

%let software=SAS;
%let 软件=SAS;            *Chinese;
%let ソフトウェア=SAS;    *Japenese;

%put &=software;
SOFTWARE=SAS

%put &=软件;
软件=SAS

%put &=ソフトウェア;
ソフトウェア=SAS

Macro variables whose name are MBCS characters behaves normal.

Checking sashelp.vmacro, 软件 and ソフトウェア are found.

I am using SAS 9.4 M8 on Win11. After multiple attempts, I confirm that both two-byte and three-byte characters can be used as macro variable names.

Why MBCS characters can be macro variable name? How encoding impact macro variable store and parsing? Is it a bug?

Re: What happend when using MBCS character as macro variable name?

yabwon — Mon, 20 Jan 2025 10:29:32 GMT

I did a test in session with single byte encoding for Polish language:

%put &=sysencoding.;

%let software=SAS;
%let ŻÓŁĆ=sas;            *Polish;

data test;
  set sashelp.vmacro;
run;

data _null_;
  x = symget('software');
  put x=;
run;

data _null_;
  x = symget('ŻÓŁĆ');
  put x=;
run;

Log:

It allows me to create macrovariable with name ŻÓŁĆ and call it with symget()

Call with %put statement worked as well:

Fun fact, when you preview sashelp.vmacro, when macrovariable name is not selected you can see:

and when you select it:

Windows 10, SAS 9.4M8, single byte session.

You can count me in to the audience for the answers to your questions.

All the best

Bart

Re: What happend when using MBCS character as macro variable name?

Kurt_Bremser — Mon, 20 Jan 2025 11:09:29 GMT

For me, this is a

BUG

Such things should never be allowed, but since the introduction of VALIDVARNAME=ANY idiocy runs rampant in the SAS world.

Re: What happend when using MBCS character as macro variable name?

yabwon — Mon, 20 Jan 2025 12:51:04 GMT

Kurt,

I agree with your opinion on this, it should not be allowed.

But it's not only a SAS case, in some languages it's done purposely: https://docs.julialang.org/en/v1/manual/variables/#man-variables

Bart