1 files changed, 53 insertions, 0 deletions
diff --git a/src/library/scala/dbc/datatype/ApproximateNumeric.scala b/src/library/scala/dbc/datatype/ApproximateNumeric.scala
new file mode 100644
index 0000000000..d75da1eb50
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+++ b/src/library/scala/dbc/datatype/ApproximateNumeric.scala
@@ -0,0 +1,53 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2005, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+package scala.dbc.datatype;
+
+/** A type category for all SQL types that store varying-precision
+ * numbers.
+ */
+abstract class ApproximateNumeric[Type] (
+  override val nativeTypeId: DataType.Id
+) extends datatype.Numeric[Type](nativeTypeId) {
+
+  def isEquivalent(datatype: DataType) = datatype match {
+    case dt: ApproximateNumeric[Type] =>
+      (nativeTypeId == dt.nativeTypeId &&
+       precisionRadix == dt.precisionRadix &&
+       precision == dt.precision &&
+       signed == dt.signed)
+    case _ =>
+      false
+  }
+
+  def isSubtypeOf (datatype:DataType) = datatype match {
+    case dt:ApproximateNumeric[Type] =>
+      (nativeTypeId == dt.nativeTypeId &&
+       precisionRadix == dt.precisionRadix &&
+       precision <= dt.precision &&
+       signed == dt.signed)
+    case _ =>
+      false
+  }
+
+  /** A SQL-99 compliant string representation of the type.
+   *  <h3>Compatibility notice</h3> This method assumes that a real
+   *  uses 32 bits and a double 64. This is not defined in the
+   *  standard but is usually the case.
+   */
+  override def sqlString: java.lang.String = Tuple2(precisionRadix,precision) match {
+    case Tuple2(2,64) => "REAL"
+    case Tuple2(2,128) => "DOUBLE PRECISION"
+    case Tuple2(2,p) =>
+      throw exception.UnsupportedFeature("SQL-99 does not support an approximate numeric type with a binary defined precision other than 16, 32 and 64 bits");
+    case Tuple2(10,p) => "FLOAT (" + p.toString() + ")"
+    case Tuple2(pr,_) =>
+      throw exception.UnsupportedFeature("SQL-99 does not support the precision of an approximate numeric type to be defined in a radix other than 2 or 10");
+  }
+
+}