Dnia 23-12-2009 o godz. 13:19 Tim Chase napisał(a): > Mikołaj Machowski wrote: > >> I have all book on gvim but no one tells me the best practice to have > >> good performance when we write vimscript. > > > > 1. In regexps avoid when possible * wildcard. > > I've never had problems with this, but it may affect long lines.
Simple test on big file - trimming whitespaces from end of line: %s/\s*$// %s/\s\+$// Basically this is special case of my second tip - * matches everywhere, \+ tests if action is necessary. > Unless your test is something simple instead of a regep, the regex > engine ends up parsing the line twice, the first time for the test and > the second time for the substitute. So if you can make a quick > non-regex determination on the line like > > if (line[0] == 'a') > s/complexregex/replacement/ > endif > > it will be faster. But checking for regex containment like > > if line=~'complexregex' > s/complexregex/replacement/ > endif > > will just be slower. True (and I thought obvious) but '=~' or stridx() works my way even with long strings or simple regexps (without * ;). IMO usually worth to try. This is other way of :g/simpleregexp/s/complexregexp/replacement/ instead of :%s/complexregexp/replacement/ Sad truth about such optimizations is that they often take more time to implement than actual savings during execution :D m. ---------------------------------------------------- Wygraj nagrody za kupowanie prezentów - zobacz: http://klik.wp.pl/?adr=http%3A%2F%2Fcorto.www.wp.pl%2Fas%2Ftaniokonkurs.html&sid=935 -- You received this message from the "vim_use" maillist. For more information, visit http://www.vim.org/maillist.php
