Writing expression errors in log file

I4GL writes expression errors in the log file defined by startlog(), while FGL does not.

With IBM® Informix® 4GL, after opening an error log file with the startlog() function, if a type conversion occurs in an expression, for example when passing an invalid DATE string to the weekday() function, errors like -1206 are written to the log file:

MAIN
    DEFINE r INT
    CALL startlog("mylog.err")
    LET r = weekday("02291999")
    DISPLAY r
END MAIN

In such case, Genero BDL will not write type conversion errors in the log file: For Genero this is an expression error. I4GL continues with the statement and throws the error after the complete statement. Genero throws the error in the middle of the statement.

In such case, review the code and use a DATE variable with a value date value. Consider using the WHENEVER ANY ERROR STOP expection handler, to detect invalid type conversions and stop the program:

MAIN
    DEFINE r INT
    DEFINE d DATE
    WHENEVER ANY ERROR STOP
    LET d = "02291999"
    LET r = weekday(d)
    DISPLAY r
END MAIN

Output with FGL:

$ fglcomp main.4gl && fglrun main.42m
Program stopped at 'main.4gl', line number 5.
FORMS statement error number -1206.
Invalid day in date.