stanfordnlp/CoreNLP · error · IllegalArgumentException

Invalid interval

Error message

Invalid interval: ${a},${b}

What it means

Interval's protected constructor validates that endpoint a does not compare greater than endpoint b. Passing endpoints in the wrong order throws IllegalArgumentException with both endpoints in the message.

Solutions

1. Ensure a <= b per the element's natural ordering before constructing
2. Normalize with Interval.toInterval(a,b) or the ordered factory, which returns null / reorders for invalid inputs rather than throwing
3. Check the compareTo implementation of your endpoint type for correctness

Example fix

// before
Interval<Integer> iv = new Interval<>(5, 2); // throws
// after
Interval<Integer> iv = (5 <= 2) ? new Interval<>(5, 2) : new Interval<>(2, 5);

if (a.compareTo(b) > 0) { E tmp = a; a = b; b = tmp; }

boolean validInterval(Comparable<?> a, Comparable<?> b) { return a.compareTo(b) <= 0; }

try { Interval<E> iv = new Interval<>(a, b, flags); } catch (IllegalArgumentException e) { /* swap or reject endpoints */ }

When it happens

Trigger: Constructing an Interval (directly via the protected constructor or subclasses/relative-interval paths) where a.compareTo(b) > 0, i.e. start after end.

Common situations: Swapped arguments when creating spans; computing endpoints dynamically (e.g. min/max of token offsets) and getting them reversed; using custom Comparables whose compareTo is inconsistent.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Attempt to open file with null name
• Bad arguments: " + x + " and " + lambda
• Collection elements must be Files or Strings
• conditionalLogProbGivenFirst requires of one less than…
• conditionalLogProbGivenNext requires given one less than…

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/aea22052247ebd1f. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/util/Interval.java:330

   */
  public static final int REL_FLAGS_INTERVAL_UNKNOWN = 0x00770000;

  public static final int REL_FLAGS_INTERVAL_ALMOST_SAME = 0x01000000;
  public static final int REL_FLAGS_INTERVAL_ALMOST_BEFORE = 0x01000000;
  public static final int REL_FLAGS_INTERVAL_ALMOST_AFTER = 0x01000000;

//  public final static int REL_FLAGS_INTERVAL_ALMOST_OVERLAP = 0x10000000;
//  public final static int REL_FLAGS_INTERVAL_ALMOST_INSIDE = 0x20000000;
//  public final static int REL_FLAGS_INTERVAL_ALMOST_CONTAIN = 0x40000000;

  public static final int REL_FLAGS_INTERVAL_FUZZY = 0x80000000;

  protected Interval(E a, E b, int flags) {
    super(a,b);
    this.flags = flags;
    int comp = a.compareTo(b);
    if (comp > 0) {
      throw new IllegalArgumentException("Invalid interval: " + a + "," + b);
    }
  }

  /**
   * Create an interval with the specified endpoints in the specified order.
   * Returns null if a does not come before b (invalid interval).
   *
   * @param a start endpoints
   * @param b end endpoint
   * @param <E> type of the interval endpoints
   * @return Interval with endpoints in specified order, null if a does not come before b
   */
  public static <E extends Comparable<E>> Interval<E> toInterval(E a, E b) {
    return toInterval(a,b,0);
  }

  /**
   * Create an interval with the specified endpoints in the specified order,

View on GitHub (pinned to 1b7edd19c4)