{
  "description": "An expression that provides an alternative definition of the content of the value set (compose). There are two different ways to use this expression extension: If both an expression (this extension) and a compose element is present, the compose is understood to the make the same statement as the expression. If there is no compose, the expression is the only definition of the value set, and the value set can only be processed by a server that understands the expression syntax, the expression is computable.",
  "_filename": "StructureDefinition-valueset-expression.json",
  "package_name": "hl7.fhir.uv.extensions.r4",
  "date": "2020-12-28T16:55:11+11:00",
  "derivation": "constraint",
  "publisher": "HL7 International / Terminology Infrastructure",
  "fhirVersion": "5.0.0",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "VSExpression",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": "false",
  "resourceType": "StructureDefinition",
  "title": "ValueSet Expression",
  "package_version": "5.1.0-ballot1",
  "extension": [ {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode": "ti"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
    "valueInteger": 3
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
    "valueCode": "trial-use"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics",
    "valueCode": "can-bind"
  } ],
  "snapshot": {
    "element": [ {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension",
      "min": 0,
      "definition": "An expression that provides an alternative definition of the content of the value set (compose). There are two different ways to use this expression extension: If both an expression (this extension) and a compose element is present, the compose is understood to the make the same statement as the expression. If there is no compose, the expression is the only definition of the value set, and the value set can only be processed by a server that understands the expression syntax, the expression is computable.",
      "isModifier": false,
      "short": "An alternative computable expression of the value set content",
      "max": "1",
      "id": "Extension",
      "comment": "The expression may be a reference or the actual expression, and is expected to be in a computable format. Use the [rules-text extension](StructureDefinition-valueset-rules-text.html) for a non-computable expression of the value set definition (compose).",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Extension"
      }
    }, {
      "path": "Extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/valueset-expression",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.url",
      "comment": "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.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/R5/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "Expression"
      } ],
      "max": "1",
      "id": "Extension.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    } ]
  },
  "status": "active",
  "id": "e7b4ed5f-1f35-4d22-acfe-dd52b9ae2b89",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/valueset-expression",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1211",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "ValueSet"
  } ],
  "version": "5.1.0-ballot1",
  "differential": {
    "element": [ {
      "id": "Extension",
      "max": "1",
      "min": 0,
      "path": "Extension",
      "short": "An alternative computable expression of the value set content",
      "comment": "The expression may be a reference or the actual expression, and is expected to be in a computable format. Use the [rules-text extension](StructureDefinition-valueset-rules-text.html) for a non-computable expression of the value set definition (compose).",
      "definition": "An expression that provides an alternative definition of the content of the value set (compose). There are two different ways to use this expression extension: If both an expression (this extension) and a compose element is present, the compose is understood to the make the same statement as the expression. If there is no compose, the expression is the only definition of the value set, and the value set can only be processed by a server that understands the expression syntax, the expression is computable."
    }, {
      "id": "Extension.extension",
      "max": "0",
      "path": "Extension.extension"
    }, {
      "id": "Extension.url",
      "path": "Extension.url",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/valueset-expression"
    }, {
      "id": "Extension.value[x]",
      "min": 1,
      "path": "Extension.value[x]",
      "type": [ {
        "code": "Expression"
      } ]
    } ]
  },
  "contact": [ {
    "telecom": [ {
      "value": "http://www.hl7.org/Special/committees/Vocab",
      "system": "url"
    } ]
  } ],
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}