Question

Good day,

I would like to know if that’s possible using RegExp and if so, how.

Here is the problem:

In a string, I have multiple pattern that correspond to colors:

{r for dark red
{R for bright red
{G for bright green
{W for white
{* for black
... and so on...

Sometimes the data I’m parsing contains lot of useless color changes
Example:

{r{Gthis text is finally green

The {r is totally useless there. It wouldn’t if the string was {rSomething {Gthis text is finally green

I would like a way to match every {<color references> that is right before any other {<color references> and leaves the last one in place.

{r{Gthis text is green -> {Gthis text is green
That text is {R{rdark red -> That text is {rdark red

Is that an easy way to do that?

I am aware that this problem is really particular and will probably never help anyone else.

But help would be really appreciate.

Thank you!

PS: The codes is used in Javascript so if possible, I would like a solution working in Javascript.

Edit:

I must be able to do {Y{r{Gthis te{*xt {Y{yis green and get {Gthis te{*xt {yis green

Answer 1

Here’s a method that works. It works like this:

1. Search for one or more color codes follow by another color code.
2. A color code is considered a { followed by any other single character except a {. If there are only a specified set of color codes that you want to allow or there are more characters that are not allowable color codes, then those could also be added to the regex, but you didn’t specify that additional info.
3. The regex for a single color code is this: \{[^\{]. This is a { followed by any single character that is not a {. If you want it to only be alpha characters, it could be changed to this: \{[a-zA-Z].
4. Replace the multiple consecutive color codes with the last color code using the sub-matches from the match.
5. This technique will remove all but the last color code even when there are more than two color codes in a row.
6. This technique will not remove things that don’t look like valid color codes like {{.

This works for any character in the color code since you looked like you had a long list of valid single character codes. But, it protects against {{ which it will not treat as a color code.

var str = "{r{G{ythis text is finally green";
var result = str.replace(/(\{[^\{])+(\{[^\{])/g, "$2");

or to allow just alpha characters to be a color code character, it would be this:

var result = str.replace(/(\{[a-zA-Z])+(\{[a-zA-Z])/g, "$2");

You can see a test fiddle here: http://jsfiddle.net/jfriend00/jNXUz/