precision

<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="quantity-precision"/> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="fhir"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/quantity-precision"/> 
  <version value="5.0.0-ballot"/> 
  <name value="precision"/> 
  <status value="draft"/> 
  <experimental value="false"/> 
  <date value="2015-02-28"/> 
  <publisher value="Health Level Seven, Inc. - FHIR Core WG"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://hl7.org/special/committees/FHIR"/> 
    </telecom> 
  </contact> 
  <description value="Explicit precision of the number. This is the number of significant decimal places after
   the decimal point, irrespective of how many are actually present in the explicitly represented
   decimal."/> 
  <fhirVersion value="5.0.0-ballot"/> 
  <mapping> 
    <identity value="v2"/> 
    <uri value="http://hl7.org/v2"/> 
    <name value="HL7 v2 Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <kind value="complex-type"/> 
  <abstract value="false"/> 
  <context> 
    <type value="element"/> 
    <expression value="decimal"/> 
  </context> 
  <type value="Extension"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
  <derivation value="constraint"/> 
  <snapshot> 
    <element id="Extension">
      <path value="Extension"/> 
      <short value="Explicit precision (number of significant decimal places)"/> 
      <definition value="Explicit precision of the number. This is the number of significant decimal places after
       the decimal point, irrespective of how many are actually present in the explicitly represented
       decimal."/> 
      <comment value="The presence of this extension does not change conformance expectations with regard to
       rendering and calculations that use the number - these are still based on the raw decimal
       value. Applications that perform calculations SHALL ensure that this extension is removed
       or updated to the correct precision value if the number is changed. Applications should
       consider using the exponential form (e.g. 2.10e3) on the raw decimal to manage significant
       figures, but should be mindful of human display when doing so."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Extension.id">
      <path value="Extension.id"/> 
      <representation value="xmlAttr"/> 
      <short value="Unique id for inter-element referencing"/> 
      <definition value="Unique id for the element within a resource (for internal references). This may be any
       string value that does not contain spaces."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Element.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="id"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension">
      <path value="Extension.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <description value="Extensions are always sliced by (at least) url"/> 
        <rules value="open"/> 
      </slicing> 
      <short value="Extension"/> 
      <definition value="An Extension"/> 
      <min value="0"/> 
      <max value="0"/> 
      <base> 
        <path value="Element.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="Extension.url">
      <path value="Extension.url"/> 
      <representation value="xmlAttr"/> 
      <short value="identifies the meaning of the extension"/> 
      <definition value="Source of the definition for the extension code - a logical name or a URL."/> 
      <comment value="The definition may point directly to a computable or human-readable definition of the
       extensibility codes, or it may be a logical URI as declared in some other specification.
       The definition SHALL be a URI for the Structure Definition defining the extension."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.url"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="uri"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/quantity-precision"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/> 
      <short value="Value of extension"/> 
      <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensi
      bility.html) for a list)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.value[x]"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="integer"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="Extension">
      <path value="Extension"/> 
      <short value="Explicit precision (number of significant decimal places)"/> 
      <definition value="Explicit precision of the number. This is the number of significant decimal places after
       the decimal point, irrespective of how many are actually present in the explicitly represented
       decimal."/> 
      <comment value="The presence of this extension does not change conformance expectations with regard to
       rendering and calculations that use the number - these are still based on the raw decimal
       value. Applications that perform calculations SHALL ensure that this extension is removed
       or updated to the correct precision value if the number is changed. Applications should
       consider using the exponential form (e.g. 2.10e3) on the raw decimal to manage significant
       figures, but should be mindful of human display when doing so."/> 
      <min value="0"/> 
      <max value="1"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension">
      <path value="Extension.extension"/> 
      <max value="0"/> 
    </element> 
    <element id="Extension.url">
      <path value="Extension.url"/> 
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/quantity-precision"/> 
    </element> 
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/> 
      <min value="1"/> 
      <type> 
        <code value="integer"/> 
      </type> 
    </element> 
  </differential> 
</StructureDefinition>