// a persistent map using a clever combination of persisting and logging

// and with case-insensitive keys

// (well, only logging as of now)

// Note: don't put in static initializer (programID not set yet)

static class PersistentCIMap<B> extends AbstractMap<S, B> {

  new Map<S, B> m;

  File file;

  PersistentCIMap(S fileName) {

    this(getProgramFile(fileName));

  }

  PersistentCIMap(S progID, S fileName) {

    this(getProgramFile(progID, fileName));

  }

  *(File *file) {

    for (S s : scanLog(file)) pcall {

      L l = cast unstructure(s);

      if (eq(l.get(0), "add"))

        m.put(toLowerCase((S) l.get(1)), (B) l.get(2));

      else if (eq(l.get(0), "remove"))

        m.remove(toLowerCase((S) l.get(1)));

      else

        print("Unknown command in log: " + l.get(0));

    }

  }

  // just delegates

  public int size() {

    ret m.size();

  }

  public B get(O a) {

    ret m.get(toLowerCase((S) a));

  }

  public boolean containsKey(O a) {

    ret m.containsKey(toLowerCase((S) a));

  }

  // TODO: calling remove() in the iterator will have unpersisted

  // effects.

  public Set<Map.Entry<S, B>> entrySet() {

    ret m.entrySet();

  }

  // delegates with logging

  public B put(S a, B b) {

    a = toLowerCase(a);

    B c = m.get(a);

    if (neq(b, c)) {

      m.put(a, b);

      logQuoted(file, structure(litlist("add", a, b)));

    }

    ret c;

  }

  public B remove(O a) {

    a = toLowerCase((S) a);

    B result = m.remove(a);

    logQuoted(file, structure(litlist("remove", a)));

    ret result;

  }

}