Definitions

accessModifier

Controls the visibility of a definition. Public definitions are accessible from other libraries; private definitions are only accessible within the library in which they are defined. Defaults to public when omitted.

codeDefinition

Declares a named code from a previously declared code system. An optional display clause provides a human-readable label for the code.

codeId

The code value within a code system, expressed as a string literal. Combined with a codesystemIdentifier it uniquely identifies a clinical concept code, such as a SNOMED CT or LOINC code.

codeIdentifier

A reference to a code definition, optionally qualified with a library identifier. Used in concept definitions to list the codes that compose the concept.

codesystemDefinition

Declares a named reference to an external code system identified by a URI. An optional version specifier pins the code system to a particular release.

codesystemId

The URI that uniquely identifies a code system, expressed as a string literal. Typically a FHIR canonical URL such as 'http://snomed.info/sct'.

codesystemIdentifier

A reference to a code system definition, optionally qualified with a library identifier. Used in valueset definitions and code definitions to reference a declared code system.

codesystems

An optional clause in a valueset definition that restricts value set membership to codes from a specific set of code systems. When present, only codes from the listed code systems are considered in scope.

conceptDefinition

Declares a named concept composed of one or more previously declared codes. An optional display clause provides a human-readable label for the concept.

includeDefinition

Imports another CQL library into the current library. The optional version clause pins the included library, and the optional called clause provides a local alias for accessing its public members.

libraryDefinition

Declares the name and optional version of the CQL library. The qualified identifier may include a namespace qualifier separated by dots.

libraryIdentifier

The local alias of an included library used to qualify a reference. Matches the local name assigned by a called clause in an include definition, or the library's own name if no alias was given.

localIdentifier

A local alias assigned to an imported library or model via the called clause. It provides a short name used to qualify identifiers from that library within the current library.

parameterDefinition

Declares a named parameter that can be supplied externally when a library is evaluated. Parameters may optionally declare an access modifier, a type, and a default expression.

usingDefinition

Imports a data model into the library. The optional version clause pins the model to a specific version, and the optional called clause provides a local alias for the model name.

valuesetDefinition

Declares a named reference to a value set identified by a URI. Optionally specifies a version and restricts the code systems from which codes are drawn.

valuesetId

The URI that uniquely identifies a value set, expressed as a string literal. Typically a FHIR canonical URL such as 'http://cts.nlm.nih.gov/fhir/ValueSet/...'.

versionSpecifier

A version string used to pin a library, model, code system, or value set to a specific version. Expressed as a string literal following the version keyword.