Parsing escape characters

[Rachel Swailes]

Hi there

I am busy building a translator for the website here at work. I now have the strings that need to be translated, but I need to parse them to get them into a more user friendly format.

So I have the string
"'hello '. CATNAME . ' rachel\'s cat'"

For php, I need to keep the single quotes that mark the beginning and end of the php string.

So what I am doing is reading for every single quote to find the beginning and end of these strings. But the \' is also getting read as a plain '.

I thought about replacing all \ with \\ but I can't use the replaceAll function because it doesn't pick up the \ when they are used as escape characters

So enough rambling. And here is a plain question because if I know this I'm sure I can solve the problem.

If I have a string = "'hello '.CATNAME.' rachel\'s cat'";
How can I get it to be = "#hello #.CATNAME.# rachel\'s cat#";


Many kind regards and a wonderful weekend!
Cheers, Rachel

[Ray Stojonic]

declare an index
loop
  set index equal to the next instance of ' or -1, in which case end the loop
  if this is the first char or previous char was not a \ then
    replace the ' with a #
  end if
end loop

[ November 05, 2004: Message edited by: Ray Stojonic ]

[jefff willis]

You can try this.

I found that I couldn't do it in less that four steps.

package testing;
 
public class FilterQuote
{
 
  public FilterQuote()
  {
  }
 
  public static void main(String[] args)
  {
    FilterQuote fq = new FilterQuote();
 
    String s = "'hello '.CATNAME.' rachel\\'s cat'";
    String t = s.replaceAll("\\\\'", "__RACHEL__");
    String n = t.replaceAll("'", "#");
    String f = n.replaceAll("__RACHEL__", "\\\\'");
 
    System.out.println("s = " + s);
    System.out.println("t = " + t);
    System.out.println("n = " + n);
    System.out.println("f = " + f);
  }
}
 

s is the string, t is a temporary version of string, n is the befinnings of a new string, and f is the final string.

hack hack hack hack hack hack hack

[Ray Stojonic]

My pseudocode works just fine, but jefff got me thinking about how replaceAll is a regex savvy method, so:

"'hello '.CATNAME.' rachel\\'s cat'".replaceAll( "([^\\\\])'|^'", "$1#" );

output: #hello #.CATNAME.# rachel\'s cat#

[jefff willis]

Ray,

nice.

I spun my wheels trying to get the regex down and couldn't do it.

good job.

[Rachel Swailes]

Hi there.

I tried all except the regex one (I'm gonna play with that now.) But all of the solutions center around being able to find the \ and as I said before, when it's used as part of an escape char, myString.indexOf the \ will return a -1. So a solution based on finding this doesn't work.

Ok, going to play with the regex one now.

Cheers and thanks for the suggestions!!
Rachel

[Rachel Swailes]

OK, how bizarre is this. When I type
String a = "hello rachel\'s cat"

Java picks the escape char up as a string literal.

But when I read from a file, I can get the \. So problem solved since I am reading it from files!

Thanks to everyone for the suggestions!
Cheers,
Rachel