Consider that I want to write a macro that, for a list of arguments, will
generate one (or more) lines of code for each argument. For example
[code]
#define STATES S0, WANTDIGIT, DIGIT, REJECTING, ENDNUMBER, WAVEFORM,
FINISH, ENDOFDATA, OUTPUT_STREAM_ID
typedef enum { STATES} States;
States state = S0;
void showState()
{
#define show1(x, ...) \
case x: Serial.println(#x); break; \
__VA_OPT__(show1(__VA_ARGS__))
switch(state)
{ /* state */
show1(STATES);
} /* state */
#undef show1
}
[/code]
What I expect to generate is
[code]
show1(S0, WANTDIGIT, DIGIT, REJECTING, ENDNUMBER, WAVEFORM, FINISH,
ENDOFDATA, OUTPUT_STREAM_ID)
[/code]
Which should give me
[code]
void showState()
{
switch(state)
{ /* state */
case S0: Serial.println("S0"); break;
case WANTDIGIT: Serial.println("WANTDIGIT"); break;
//..etc.
case OUTPUT_STREAM_ID: Serial.println("OUTPUT_STREAM_ID"); break;
} /* state */
} // showState
[/code]
What I get, though, is
[code]
C:\Users\admin\OneDrive\Projects\Oscilloscope Tests\PWM_test\PWM_test.ino:
In function 'void showState()':
PWM_test:39:19: error: expected ':' before ',' token
39 | #define STATES S0, WANTDIGIT, DIGIT, REJECTING, ENDNUMBER,
WAVEFORM, FINISH, ENDOFDATA, OUTPUT_STREAM_ID
| ^
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:48:10: note: in definition of macro 'show1'
48 | case x: Serial.println(#x); break; \
| ^
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:52:12: note: in expansion of macro 'STATES'
52 | show1(STATES);
| ^~~~~~
PWM_test:39:19: error: expected primary-expression before ',' token
39 | #define STATES S0, WANTDIGIT, DIGIT, REJECTING, ENDNUMBER,
WAVEFORM, FINISH, ENDOFDATA, OUTPUT_STREAM_ID
| ^
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:48:10: note: in definition of macro 'show1'
48 | case x: Serial.println(#x); break; \
| ^
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:52:12: note: in expansion of macro 'STATES'
52 | show1(STATES);
| ^~~~~~
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'WANTDIGIT'
not handled in switch [-Wswitch]
50 | switch(state)
| ^
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'DIGIT' not
handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'REJECTING'
not handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'ENDNUMBER'
not handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'WAVEFORM' not
handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'FINISH' not
handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value 'ENDOFDATA'
not handled in switch [-Wswitch]
C:\Users\admin\OneDrive\Projects\Oscilloscope
Tests\PWM_test\PWM_test.ino:50:11: warning: enumeration value
'OUTPUT_STREAM_ID' not handled in switch [-Wswitch]
exit status 1
expected ':' before ',' token
[/code]
What is going wrong here?
Attachment:
image001.gif
Description: GIF image
