I'm not sure that regexes are the best solution here, but they seem logical enough; I'm just not sure how to actually implement this.

Basically, I want my user to be able to type in a method name and have it parsed for validity after each character input. I have defined a valid function format as a regex, and it is easy enough to test if the two match. The trouble is, I would like to be able to do a partial match, so as to let the user know, "So far, this is valid".

For example,

```
+(NSString *)thisIsAValid:(ObjectiveC *)method;

```

is a valid method. It can be matched by a simple regex string like

```
[\+-]\(w+\s*\*?\)\w+....etc...

```

. But I would love to be able to have that same regex string "match"

```
+(NSStr

```

(which I realize is sort of a backwards way of using regex). I would still not want the regex to match

```
Q)(NStr

```

Is there a way to implement something like this with standard regex functions, or would I have to do something more drastic?

Thanks so much! You guys are invaluable.

---

After further thinking, I suppose I could make my question a bit more clear (as well as a bit more succinct): Normally, one uses a regex to look for a pattern in text. I.e., how many times does "cat" or "cot" appear in this paragraph. I wish to do the opposite, look for a string "in" a regex. That is, how much of this string, starting from the beginning matches this regex. Ultimately, I would like to return the index at which the string ceases to match the regex in question.