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The following apparent quirk in macro parsing drove me batty. The
listing that follows is SPSS 15 draft output.
* If !A is a macro that expands into "'Alpha'" (with the quotes), then
ECHO 'Letter is ' + !A .
seems to be parsed with the macro expanded, to get
ECHO 'Letter is ' + 'Alpha .
and prints "Letter is Alpha".
* If !B is a macro variable whose value is "'Beta'", then
ECHO 'Letter is ' + !B .
seems to be parsed with the variable value NOT substituted for, giving
>Warning # 207 in column 6. Text: Letter is
>A '+' was found following a text string, indicating continuation, but
>the next non-blank character was not a quotation mark or an apostrophe.
The resulting generated string has the expansion, but the "+"
catenation doesn't work:
27 M> ECHO 'Letter is ' 'Beta'
I guess I expected that not just all macros, but all macro variables,
were substituted before an SPSS command was parsed at all. Doesn't seem
to be quite true, for macro variables.
=====================
Demonstration listing
=====================
DEFINE !A() 'Alpha' !ENDDEFINE.
ECHO 'Letter is ' + !A .
Letter is Alpha
DEFINE !Write_B ()
!LET !B = 'Beta'.
!LET !B = !QUOTE(!B).
ECHO 'Letter is ' + !B .
>Warning # 207 in column 6. Text: Letter is
>A '+' was found following a text string, indicating continuation, but
the
>next non-blank character was not a quotation mark or an apostrophe.
!ENDDEFINE.
PRESERVE.
SET MPRINT ON.
!Write_B.
24 M>
25 M> .
26 M>
27 M> ECHO 'Letter is ' 'Beta'
Letter is
28 M> .
RESTORE.
29 M> RESTORE.
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