in src/main/java/org/apache/sling/pipes/PipeBindings.java [193:209]
private int processMatcher(int start, String expr, StringBuilder expression, Matcher matcher) {
if (matcher.start() > start) {
if (expression.length() == 0) {
expression.append("'");
}
expression.append(expr, start, matcher.start());
}
if (expression.length() > 0) {
expression.append("' + ");
}
expression.append(matcher.group(1));
start = matcher.end();
if (start < expr.length()) {
expression.append(" + '");
}
return start;
}