From 182dca56c87d0a3f3da153956cad9229f4fc9088 Mon Sep 17 00:00:00 2001
From: Keith Alcock <github@keithalcock.com>
Date: Fri, 8 May 2026 08:57:46 -0700
Subject: [PATCH] Use ai.lum.common.Interval

This is an alternative strategy, more compatible with the original.
---
 build.sbt                                     |   5 +-
 .../scala/ai/lum/nxmlreader/Interval.scala    | 100 ------------------
 .../ai/lum/nxmlreader/NxmlDocument.scala      |   1 +
 .../ai/lum/nxmlreader/standoff/Tree.scala     |   2 +-
 4 files changed, 5 insertions(+), 103 deletions(-)
 delete mode 100644 src/main/scala/ai/lum/nxmlreader/Interval.scala

diff --git a/build.sbt b/build.sbt
index d83522f..a37ebbd 100644
--- a/build.sbt
+++ b/build.sbt
@@ -56,11 +56,12 @@ libraryDependencies ++= {
   }
 
   Seq(
+    "ai.lum"                 %% "common"                  % "0.2.1",
+    "org.scala-lang.modules" %% "scala-xml"               % scalaXmlVersion,
     // 3.2.20 of below depends on scala3-library 3.1.3, so use this one for cross-compilation.
     "org.scalatest"          %% "scalatest"               % "3.2.20" % "test",
     // 2.9.0 of below depends on scala3-library 3.1.3, so use this one for cross-compilation.
-    "org.scala-lang.modules" %% "scala-collection-compat" % "2.9.0" % "test",
-    "org.scala-lang.modules" %% "scala-xml"               % scalaXmlVersion
+    "org.scala-lang.modules" %% "scala-collection-compat" % "2.9.0" % "test"
   )
 }
 
diff --git a/src/main/scala/ai/lum/nxmlreader/Interval.scala b/src/main/scala/ai/lum/nxmlreader/Interval.scala
deleted file mode 100644
index 3d3c24a..0000000
--- a/src/main/scala/ai/lum/nxmlreader/Interval.scala
+++ /dev/null
@@ -1,100 +0,0 @@
-package ai.lum.nxmlreader
-
-class Interval private (val start: Int, val end: Int) extends Ordered[Interval] {
-
-  override def toString: String = {
-    if (isEmpty) "{}"
-    else if (length == 1) s"{$start}"
-    else s"[$start, $end)"
-  }
-
-  // Since Intervals will be used as keys in a map,
-  // both equals and hashCode are necessary.
-  override def equals(that: Any): Boolean = that match {
-    case that: Interval => that.canEqual(this) && {
-      if (this.isEmpty) that.isEmpty
-      else {
-        // Since this is not empty, it will not match
-        // an empty that.
-        this.start == that.start &&
-        this.end == that.end
-      }
-    }
-    case _ => false
-  }
-
-  def canEqual(that: Any): Boolean = that.isInstanceOf[Interval]
-
-  override def hashCode: Int = {
-    start * 23 + end
-  }
-
-  def length = end - start
-
-  def isEmpty: Boolean = length <= 0
-
-  def intersects(that: Interval): Boolean = {
-    if (this.isEmpty || that.isEmpty)
-      false
-    else if (this.start < that.start)
-      this.end > that.start
-    else if (that.start < this.start)
-      that.end > this.start
-    else
-      true
-  }
-
-  def borders(that: Interval): Boolean = {
-    if (this.isEmpty || that.isEmpty) false
-    else {
-      this.start == that.end ||
-      that.start == this.end
-    }
-  }
-
-  override def compare(that: Interval): Int = {
-    if (this.start > that.start) 1
-    else if (this.start < that.start) -1
-    else this.length - that.length
-  }
-
-  def union(that: Interval): Interval = {
-    if (this.isEmpty) that
-    else if (that.isEmpty) this
-    else {
-      require(this.borders(that) || this.intersects(that))
-      Interval.open(
-        math.min(this.start, that.start),
-        math.max(this.end,   that.end)
-      )
-    }
-  }
-}
-
-object Interval {
-  val emptyInterval = new Interval(0, 0)
-
-  def apply(start: Int, end: Int): Interval = {
-    require(start <= end, s"end < start: $end < $start")
-    if (start < end) new Interval(start, end)
-    else emptyInterval
-  }
-
-  def singleton(i: Int): Interval = apply(i, i + 1)
-
-  def open(start: Int, end: Int): Interval = apply(start, end)
-
-  def ofLength(start: Int, length: Int): Interval = open(start, start + length)
-
-  def union(col: Seq[Interval]): Interval = {
-    val sorted = col.sorted
-
-    try {
-      sorted.reduceLeft(_.union(_))
-    }
-    catch {
-      case _: IllegalArgumentException =>
-        throw new IllegalArgumentException("gap in intervals: " + sorted)
-    }
-  }
-}
diff --git a/src/main/scala/ai/lum/nxmlreader/NxmlDocument.scala b/src/main/scala/ai/lum/nxmlreader/NxmlDocument.scala
index 30e1648..c42742c 100644
--- a/src/main/scala/ai/lum/nxmlreader/NxmlDocument.scala
+++ b/src/main/scala/ai/lum/nxmlreader/NxmlDocument.scala
@@ -1,5 +1,6 @@
 package ai.lum.nxmlreader
 
+import ai.lum.common.Interval
 import ai.lum.nxmlreader.standoff._
 
 import scala.annotation.tailrec
diff --git a/src/main/scala/ai/lum/nxmlreader/standoff/Tree.scala b/src/main/scala/ai/lum/nxmlreader/standoff/Tree.scala
index 2b7e426..316d824 100644
--- a/src/main/scala/ai/lum/nxmlreader/standoff/Tree.scala
+++ b/src/main/scala/ai/lum/nxmlreader/standoff/Tree.scala
@@ -1,6 +1,6 @@
 package ai.lum.nxmlreader.standoff
 
-import ai.lum.nxmlreader.Interval
+import ai.lum.common.Interval
 
 sealed trait Tree {