User comments are descriptions or explanatory notes added to or interspersed among the statements of the source code. Such information may be particularly helpful in understanding and maintenaing source code that was written or edited by another programmer. Also, the characters marking the beginning of a comment can be used to temporarily disable the function of a statement or several source code lines for test purposes.
In Natural, you have the following possibilities for entering your comments in source code:
If you wish to use an entire source-code line for a user comment, you enter one of the following at the beginning of the line:
an asterisk and a blank (* ),
two asterisks (**), or
a slash and an asterisk (/*).
* USER COMMENT ** USER COMMENT /* USER COMMENT
As can be seen from the following example, comment lines may also be used to provide for a clear source code structure.
** Example 'LOGICX03': BREAK option in logical condition
************************************************************************
DEFINE DATA LOCAL
1 EMPLOY-VIEW VIEW OF EMPLOYEES
2 NAME
2 FIRST-NAME
2 BIRTH
*
1 #BIRTH (A8)
END-DEFINE
*
LIMIT 10
READ EMPLOY-VIEW BY BIRTH
MOVE EDITED BIRTH (EM=YYYYMMDD) TO #BIRTH
/*
IF BREAK OF #BIRTH /6/
NEWPAGE IF LESS THAN 5 LINES LEFT
WRITE / '-' (50) /
END-IF
/*
DISPLAY NOTITLE BIRTH (EM=YYYY-MM-DD) NAME FIRST-NAME
END-READ
END
If you wish to use only the latter part of a source-code line for a user comment, you enter a blank, a slash and an asterisk ( /*); the remainder of the line after this notation is thus marked as a comment:
ADD 5 TO #A /* USER COMMENT
** Example 'LOGICX04': IS option as format/length check
************************************************************************
DEFINE DATA LOCAL
1 #FIELDA (A10) /* INPUT FIELD TO BE CHECKED
1 #FIELDB (N5) /* RECEIVING FIELD OF VAL FUNCTION
1 #DATE (A10) /* INPUT FIELD FOR DATE
END-DEFINE
*
INPUT #DATE #FIELDA
IF #DATE IS(D)
IF #FIELDA IS (N5)
COMPUTE #FIELDB = VAL(#FIELDA)
WRITE NOTITLE 'VAL FUNCTION OK' // '=' #FIELDA '=' #FIELDB
ELSE
REINPUT 'FIELD DOES NOT FIT INTO N5 FORMAT'
MARK *#FIELDA
END-IF
ELSE
REINPUT 'INPUT IS NOT IN DATE FORMAT (YY-MM-DD) '
MARK *#DATE
END-IF
*
END