Difference between revisions of "BEGIN SEQUENCE"
From Recital Documentation Wiki
Yvonnemilne (Talk | contribs) |
Yvonnemilne (Talk | contribs) |
||
| Line 1: | Line 1: | ||
| − | |||
| − | |||
| − | |||
==Class== | ==Class== | ||
Error Handling and Debugging | Error Handling and Debugging | ||
| Line 37: | Line 34: | ||
error = .F. | error = .F. | ||
begin sequence | begin sequence | ||
| + | |||
do while not eof() | do while not eof() | ||
| − | + | if empty(name) | |
| − | + | rec = recno() | |
| − | + | error = .T. | |
| − | + | break | |
| − | + | else | |
| − | + | display name | |
| − | + | endif | |
| − | + | skip | |
enddo | enddo | ||
| + | |||
end sequence | end sequence | ||
| + | |||
if error | if error | ||
| − | + | set message to "Error: No name in record; &rec." | |
else | else | ||
| − | + | set message to "End of file reached." | |
endif | endif | ||
</code> | </code> | ||
Revision as of 11:14, 21 April 2009
Class
Error Handling and Debugging
Purpose
Start error-handling block
Syntax
BEGIN SEQUENCE
<command>
[BREAK]
<command>
END SEQUENCE
See Also
Description
The main purpose of the BEGIN SEQUENCE ... BREAK ... END SEQUENCE construct is to allow for programmable error handling. The commands that follow the END SEQUENCE command will normally be devoted to error handling and will be executed immediately.
BREAK
The BREAK keyword can be used whenever the program commands detect an error. For this purpose, BREAK may appear at any depth within nested procedures. When BREAK is encountered, all stacked procedures will unwind automatically.
Example
error = .F. begin sequence do while not eof() if empty(name) rec = recno() error = .T. break else display name endif skip enddo end sequence if error set message to "Error: No name in record; &rec." else set message to "End of file reached." endif
Products
Recital Database Server, Recital Mirage Server, Recital Terminal Developer
