src/main/java/com/basistech/tclre/Compiler.java
private int newlacon(State begin, State end, int pos) {
        if (lacons.size() == 0) {
            // skip 0
            lacons.add(null);
        }
        Subre sub = new Subre((char)0, 0, begin, end);
        sub.subno = pos;
        lacons.add(sub);
        return lacons.size() - 1; // it's the index into the array, -1.
    }
private int newlacon(State begin, State end, int pos) {
        if (lacons.size() == 0) {
            // skip 0
            lacons.add(null);
        }
        Subre sub = new Subre((char)0, 0, begin, end);
        sub.subno = pos;
        lacons.add(sub);
        return lacons.size() - 1; // it's the index into the array, -1.
    }
newlacon - allocate a lookahead-constraint subRE

@return lacon number