I need a editor in which I could customise highlighting so that it could highlight sentences in which bad programming style (I have my own rules for this) would be underlined. example "if(a==1)DoSomething();" would be underlined, and "if ( a == 1 ) DoSomething();" won't be underlined. Which text editor allows such customisation?
Why, Vim and Emacs of course. Both are very customizable - whether you're leaning more towards regex/Vimscript/Python/Ruby/Perl or ELISP will probably decide your favourite. ELISP is somewhat more structured, and Emacs highlighter is a bit better, but unless you've worked with LISP before, it will look like chaos. The first bunch of languages are probably more familiar to you (since they're rather mainstream nowadays). In either case, don't expect big results in an afternoon.