Thanks Geert for your response.. I agree with you on those lines., that's the default way we handle exception scenarios in other programming languages. The question around the try catch block is more with respect to the impact on parallel processing and lazy evaluations which is applicable for ML ..
On Thu, May 5, 2011 at 1:46 PM, Geert Josten <[email protected]>wrote: > Hi Abishek, > > > > What is meant with ‘reduce the use of try/catch’ is that you should make > sensible use of try/catch and manually throwing exceptions using the error > function. Exception handling is (relatively) slow in most languages, so if > you have the option to prevent a throw and a catch by simply using an extra > if, then do so. On other occasions, you might want to be sure certain > statements are always executed, or that certain actions are taken when an > exception is thrown. > > > > A good example is trying to connect to an external resource using > xdmp:http-get. If it fails with a timeout, it throws an exception. It is not > uncommon to put a try catch around it and connect to a different resource, > or return some default value instead. > > > > Personally, I don’t bother about try/catch performance too much. Just use > them sensibly.. > > > > Kind regards, > > Geert > > > > *Van:* [email protected] [mailto: > [email protected]] *Namens *Abishek N > *Verzonden:* donderdag 5 mei 2011 19:05 > *Aan:* General MarkLogic Developer Discussion > *Onderwerp:* [MarkLogic Dev General] Try catch in xquery > > > > What are the pointers while exception handling in ml? One of the pointers > we have already heard is > "Reduce the use of try/catch where applicable. This is especially true in > situations where try/catch blocks may be nested. Try/catch blocks have a > negative impact on performance due to the fact that the block must be > completely evaluated before the server can move on. " > > So does this mean that we have to avoid having try catch blocks around > lots of lines of code? and try to keep the try catch block as short as > possible.. > So in the eg. below statement 3 try catch block would not be triggered > until the statement 1 and statement 2 get executed, is that correct? Since > statement 2 is outside try catches there is a possibility it could get lazy > evaluated. > > try { > statement 1 > } > catch{ > } > > statement 2 > > try { > statement 3 > } > catch{ > } > > Similarly in the below scenario.. if we have nested try catches like > below... statement 5 would not get executed until statement 1,2,3 get > executed.. however statement 4 could get executed.. > try { > > try > { > statement 1 > } > catch{ > } > > statement 2 > > try { > statement 3 > } > catch{ > } > > > } > > statement 4 > > try { > statement 5 > } > catch{ > } > > Please confirm if our understanding is correct. > > Regards Abishek > > _______________________________________________ > General mailing list > [email protected] > http://developer.marklogic.com/mailman/listinfo/general > > -- Regards Abishek
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