in src/main/org/apache/ant/props/stringops/ReplaceOperation.java [42:49]
protected final Object evaluate(String[] groups, PropertyHelper propertyHelper) {
Object value = propertyHelper.getProperty(groups[1]);
int replaceOption = "//".equals(groups[2]) ? Regexp.REPLACE_ALL : Regexp.REPLACE_FIRST;
StringBuffer sb = new StringBuffer(groups[3]);
convertToRegex(sb);
return value == null ? null : createRegexp(sb.toString(), propertyHelper.getProject())
.substitute(value.toString(), groups[4], replaceOption);
}