1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
package Torello.Java;

import Torello.Java.Function.IntCharFunction;

class CharArrToStrReplFunc
{
    static String replace(
            final boolean                   ignoreCase,
            final String                    s,
            final char[]                    matchCharsInput,
            final IntCharFunction<String>   replaceFunction
        )
    {
        // Use a StringBuilder.  It is easier since the 'Replace Function' is going to be
        // *GENERATING* a new String each and every time there is a match.  This is essentially
        // what class StringBuilder was deigned for.

        StringBuilder sb = new StringBuilder();


        // If the case of the characters is being ignored, it is easier to just set them all
        // to lower-case right now.

        final char[] matchChars;

        if (ignoreCase)
        {
            matchChars = new char[matchCharsInput.length]; // matchCharsInput.clone();

            for (int i=0; i < matchChars.length; i++)
                matchChars[i] = Character.toLowerCase(matchCharsInput[i]);
        }

        else matchChars = matchCharsInput;


        // IMPORTANT: This entire method is "The Easy Way"  Here, we are just reusing Java's
        //            StringBuilder class to build the String, piece-by-piece.  It is
        //            unknown whether this is less efficient than working with a char[] array

        TOP:
        for (int i=0; i < s.length(); i++)
        {
            char c = ignoreCase ? Character.toLowerCase(s.charAt(i)) : s.charAt(i);

            for (int j=0; j < matchChars.length; j++)

                if (c == matchChars[j])
                { 
                    sb.append(replaceFunction.apply(i, c));
                    continue TOP;
                }

            sb.append(s.charAt(i));
        }

        return sb.toString();
    }
}