Package org.cqframework.cql.elm.execution

Class Subtract

  • All Implemented Interfaces:
    org.jvnet.jaxb2_commons.lang.Equals2, org.jvnet.jaxb2_commons.lang.HashCode2, org.jvnet.jaxb2_commons.lang.ToString2
    Direct Known Subclasses:
    SubtractEvaluator
    public class Subtract
extends BinaryExpression
implements org.jvnet.jaxb2_commons.lang.Equals2, org.jvnet.jaxb2_commons.lang.HashCode2, org.jvnet.jaxb2_commons.lang.ToString2
    The Subtract operator performs numeric subtraction of its arguments. When subtracting quantities, the dimensions of each quantity must be the same, but not necessarily the unit. For example, units of 'cm' and 'm' can be subtracted, but units of 'cm2' and 'cm' cannot. The unit of the result will be the most granular unit of either input. Attempting to operate on quantities with invalid units will result in a run-time error. The Subtract operator is defined for the Integer, Long, Decimal, and Quantity types. In addition, a time-valued Quantity can be subtracted from a Date, DateTime, or Time using this operator. For Date, DateTime, Time values, the operator returns the value of the first argument, decremented by the time-valued quantity, respecting variable length periods for calendar years and months. For Date values, the quantity unit must be one of years, months, weeks, or days. For DateTime values, the quantity unit must be one of years, months, weeks, days, hours, minutes, seconds, or milliseconds. For Time values, the quantity unit must be one of hours, minutes, seconds, or milliseconds. Note that as with any Date, Time, or DateTime operations, temporal units may be specified with either singular, plural, or UCUM units. However, to avoid the potential confusion of calendar-based date and time arithmetic with definite-duration date and time arithmetic, it is an error to attempt to subtract a definite-duration time-valued unit above days (and weeks), a calendar duration must be used. For precisions above seconds, any decimal portion of the time-valued quantity is ignored, since date/time arithmetic above seconds is performed with calendar duration semantics. For partial date/time values where the time-valued quantity is more precise than the partial date/time, the operation is performed by converting the time-based quantity to the highest specified granularity in the first argument (truncating any resulting decimal portion) and then subtracting it from the first argument. If either argument is null, the result is null. If the result of the operation cannot be represented, the result is null.

    Java class for Subtract complex type.

    The following schema fragment specifies the expected content contained within this class. 

     <complexType name="Subtract">
   <complexContent>
     <extension base="{urn:hl7-org:elm:r1}BinaryExpression">
     </extension>
   </complexContent>
 </complexType>