Re: Break or Continue in a whiel loop
"Shane Farmer" <[email protected]> Thu, 19 Oct 2006 09:06:55 +1000
| Newsgroups | gmane.comp.java.webmacro.user |
|---|---|
| Message-ID | <[email protected]> |
--===============0643593666== Content-Type: multipart/alternative; boundary="----=_Part_7485_23860354.1161212815321" ------=_Part_7485_23860354.1161212815321 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Thanks Keats for the words of wisdome. I think that has given me everything I need to finish it off. The main reason for coding a while loop was to help another developer out. Maybe #count would have worked better for him. Shane On 10/19/06, Keats Kirsch <[email protected]> wrote: > > The directive code looks pretty clean, but I'd question the need for > it. We've discussed a #while directive many times over the years, and I > have yet to see a use-case that couldn't be handled pretty well by > #foreach or #count. The general feeling was always that #while is too > dangerous because it makes it too easy for a template designer to > introduce infinite loops. > > However I think a #break directive or subdirective might be useful. > One approach might be to add an option to the directive, like: > > #foreach $var in $collection breakon $break { > #if ($var = "Bad") { #set $break = true } > } > > Then the directive could just check the value of the break variable. > > The problem with a break directive is that you would have to deal with > nested loops. This could be handled by using labels, like in Java. > > #foreach $list in $collection label "outerloop" { > #foreach $item in $list { > #if ($item = "Bad") { #break "outerloop" } > } > } > > This would be harder than the first option, and not any better really > IMHO. > > I don't think #continue would be useful. It would be difficult to code > and you can always use an #if instead, which is cleaner anyway. > > Keats > > Shane Farmer wrote: > > Hi All, > > > > I have been looking around for a while loop to no avail. As such I > > have implimented a very basic while loop directive. I am using an > > older version of WM (1.0 or 1.1) and was wondering if it possible to > > create 2 subdirectives, break and continue, and if anyone would have > > some pointers on how to go about doing this. > > > > The code is _very_ basic ATM and simply loops while ever the > > conditional arg is true and evaluates [block.write(...)] on the block > arg. > > > > Im am all ears for better design startegies for this directive as well. > > > > Thanks in advance > > Shane > > ------------------------------------------------------------------------ > > > > > ------------------------------------------------------------------------- > > Using Tomcat but need to do more? Need to support web services, > security? > > Get stuff done quickly with pre-integrated technology to make your job > easier > > Download IBM WebSphere Application Server v.1.0.1 based on Apache > Geronimo > > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Webmacro-user mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/webmacro-user > > > > > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job > easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Webmacro-user mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/webmacro-user > ------=_Part_7485_23860354.1161212815321 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline <div>Thanks Keats for the words of wisdome. I think that has given me everything I need to finish it off.</div> <div> </div> <div>The main reason for coding a while loop was to help another developer out. Maybe #count would have worked better for him.</div> <div> </div> <div>Shane<br> </div> <div><span class="gmail_quote">On 10/19/06, <b class="gmail_sendername">Keats Kirsch</b> <<a href="mailto:[email protected]">[email protected]</a>> wrote:</span> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">The directive code looks pretty clean, but I'd question the need for<br>it. We've discussed a #while directive many times over the years, and I <br>have yet to see a use-case that couldn't be handled pretty well by<br>#foreach or #count. The general feeling was always that #while is too<br>dangerous because it makes it too easy for a template designer to<br>introduce infinite loops. <br><br>However I think a #break directive or subdirective might be useful.<br>One approach might be to add an option to the directive, like:<br><br>#foreach $var in $collection breakon $break {<br>#if ($var = "Bad") { #set $break = true } <br>}<br><br>Then the directive could just check the value of the break variable.<br><br>The problem with a break directive is that you would have to deal with<br>nested loops. This could be handled by using labels, like in Java. <br><br>#foreach $list in $collection label "outerloop" {<br> #foreach $item in $list {<br> #if ($item = "Bad") { #break "outerloop" }<br> }<br>}<br><br>This would be harder than the first option, and not any better really IMHO. <br><br>I don't think #continue would be useful. It would be difficult to code<br>and you can always use an #if instead, which is cleaner anyway.<br><br>Keats<br><br>Shane Farmer wrote:<br>> Hi All,<br>><br>> I have been looking around for a while loop to no avail. As such I <br>> have implimented a very basic while loop directive. I am using an<br>> older version of WM (1.0 or 1.1) and was wondering if it possible to<br>> create 2 subdirectives, break and continue, and if anyone would have <br>> some pointers on how to go about doing this.<br>><br>> The code is _very_ basic ATM and simply loops while ever the<br>> conditional arg is true and evaluates [block.write(...)] on the block arg.<br>> <br>> Im am all ears for better design startegies for this directive as well.<br>><br>> Thanks in advance<br>> Shane<br>> ------------------------------------------------------------------------<br>><br> > -------------------------------------------------------------------------<br>> Using Tomcat but need to do more? Need to support web services, security?<br>> Get stuff done quickly with pre-integrated technology to make your job easier <br>> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo<br>> <a href="http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642">http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 </a><br>> ------------------------------------------------------------------------<br>><br>> _______________________________________________<br>> Webmacro-user mailing list<br>> <a href="mailto:[email protected]"> [email protected]</a><br>> <a href="https://lists.sourceforge.net/lists/listinfo/webmacro-user">https://lists.sourceforge.net/lists/listinfo/webmacro-user</a><br>><br><br><br><br>------------------------------------------------------------------------- <br>Using Tomcat but need to do more? Need to support web services, security?<br>Get stuff done quickly with pre-integrated technology to make your job easier<br>Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo <br><a href="http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642">http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642</a><br>_______________________________________________ <br>Webmacro-user mailing list<br><a href="mailto:[email protected]">[email protected]</a><br><a href="https://lists.sourceforge.net/lists/listinfo/webmacro-user">https://lists.sourceforge.net/lists/listinfo/webmacro-user </a><br></blockquote></div><br> ------=_Part_7485_23860354.1161212815321-- --===============0643593666== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 --===============0643593666== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Webmacro-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/webmacro-user --===============0643593666==--