@Immutable
    public static Memory stristr(String haystack, Memory needleV) {
        String needleLower;

        if (needleV.isString()) {
            needleLower = needleV.toString().toLowerCase();
        } else {
            char lower = Character.toLowerCase((char) needleV.toLong());

            needleLower = String.valueOf(lower);
        }

        String haystackLower = haystack.toLowerCase();

        int i = haystackLower.indexOf(needleLower);

        if (i >= 0) {
            return new StringMemory(haystack.substring(i));
        } else {
            return Memory.FALSE;
        }
    }
Parses the cslashes bitmap returning an actual bitmap.

@param charset the bitmap string

@return the actual bitmap
exts/jphp-zend-ext/src/main/java/org/develnext/jphp/zend/ext/standard/StringFunctions.java