From: William James <w_a_x_man@...>
Date: 2007-08-30T03:00:14+09:00
Subject: Re: gsub help

On Aug 28, 11:46 pm, Pe�a, Botp <b...@delmonte-phil.com> wrote:
> From: hurcan solter [mailto:hsol...@gmail.com]
> #   line.gsub!(/\s*([=]+)\s*/ ,' \1 ')
> #
> # But it applies every = on the line ofc, but I want to exclude
> # expressions between quotation marks ("sth=sth") or regexp (/sth=sth/).
>
> after reviewing WJames post (thanks james), i think you are not far to the solution. You just need to include the exceptions first, then gsub further to that. gsub accepts a block, so flexibility is unlimited, eg,
>
> > str
>
> => "/x==9/ { print \"x==9 and AWK is everywhere!\"; x=9 }"
>
> let's create our main regex sub and test if we can get back to the original str,
>
> > p str.gsub(/\S*\s*([=]+)\s*\S*/){|s| s }
>
> "/x==9/ { print \"x==9 and AWK is everywhere!\"; x=9 }"
> => nil
>
> ok. now let's view our captures. let's put some markers/tags.
>
> > p str.gsub(/\S*\s*([=]+)\s*\S*/){|s| "<<"+s+">>" }
>
> "<</x==9/>> { print <<\"x==9>> and AWK is everywhere!\"; <<x=9>> }"
> => nil
>
> ah, i think we're capturing right for this case of str
>
> now let's test the inner substitution. note the gsub inside the block. the expression gets simpler since we've already filtered thru the first/main regexp.
>
> > p str.gsub(/\S*\s*([=]+)\s*\S*/){|s| s.gsub(/(=+)/,' \1 ') }
>
> "/x == 9/ { print \"x == 9 and AWK is everywhere!\"; x = 9 }"
> => nil
>
> ok.
> now, let us combine that one w the first one (the noop), using an inline if (i'm assumming you want a one-liner) filtering thru the exception you want, ie, no ["\/]
>
> > p str.gsub(/\S*\s*([=]+)\s*\S*/){|s| s=~/["\/]/ ? s : s.gsub(/(=+)/,' \1 ') }
>
> "/x==9/ { print \"x==9 and AWK is everywhere!\"; x = 9 }"
> => nil


>> irb --prompt xmp
str='/x==9/ {print "so x=9 and AWK is everywhere!"; x=9 }'
    ==>"/x==9/ {print \"so x=9 and AWK is everywhere!\"; x=9 }"
str.gsub(/\S*\s*([=]+)\s*\S*/){|s|
s=~/["\/]/ ? s : s.gsub(/(=+)/,' \1 ') }
    ==>"/x==9/ {print \"so x = 9 and AWK is everywhere!\"; x = 9 }"