Hl7.Cql.Elm

Introduction

This is NCQA's and Firely's official support SDK for working with CQL on the Microsoft .NET (dotnet) platform. It contains an engine for executing ELM, and/or turning the contents of an ELM file into a .NET assembly so it can be called statically.

Release notes

This is release version 2.1 of the engine. Earlier 1.x releases will be maintained with hotfixes, but will not receive new features.

The engine has been tested by running it against the current NCQA HEDIS measures and CMS measures. There is quite some variation in how CQL is written and interpreted, so it is likely at this early stage that there will be deviations from other engines currently available.

The releases notes at firely-cql-sdk/releases for each major version will document these changes and (major) issues we have encountered.

Getting Started

• Read how to get started with the Demo solution included in the repository.
• There is a great presentation on the engine from DevDays 2023.
• The CQL section in the .NET SDK documentation
• The CQL Engine Architecture document with background documentation on the design.
• The Toolkit Services Dependency Diagrams showing the internal dependencies of the CQL SDK toolkit services.

The presentation is a good place to start, but note that we have made some minor changes to the public surface, so the names of the classes in the presentation will differ from the examples in the Demo project itself.

Dependencies

The SDK has dependencies on the following key external packages:

Cql.Firely

• Hl7.Fhir.Base: Version 5.12.0 - Base classes and utilities for FHIR support
• Hl7.Fhir.R4: Firely SDK version - FHIR R4 POCOs and serialization support

Cql.Grammar

• Antlr4.Runtime.Standard: Version 4.13.1 - ANTLR4 runtime for CQL grammar parsing

Cql.Runtime

• Microsoft.Extensions.Logging.Debug: Version 8.0.0 - Debug logging provider
• Fhir.Metrics: Version 1.3.0 - FHIR units and metrics support

Cql.CqlToElm

• Microsoft.Extensions.Configuration: Version 9.0.3 - Configuration framework
• Microsoft.Extensions.DependencyInjection: Version 8.0.0 - Dependency injection container
• Microsoft.Extensions.Logging: Version 8.0.0 - Logging abstractions

CodeGeneration.NET

• Microsoft.CodeAnalysis.CSharp: Version 4.12.0 - Roslyn C# compiler APIs
• Microsoft.Extensions.Logging.Debug: Version 8.0.0 - Debug logging provider
• Microsoft.Extensions.Logging.Console: Version 8.0.1 - Console logging provider

Cql.Compiler

• Microsoft.Extensions.Logging.Abstractions: Version 8.0.1 - Logging abstractions
• Microsoft.Extensions.Logging.Debug: Version 8.0.0 - Debug logging provider

Elm

• Microsoft.CodeAnalysis.CSharp: Version 4.12.0 - Roslyn C# compiler APIs
• System.Text.Json: Version 8.0.5 - High-performance JSON serialization

Cql.Packaging

• Hl7.Fhir.R4: Firely SDK version - FHIR R4 POCOs and serialization support

PackagerCLI (cql-package tool)

• Microsoft.Extensions.Hosting: Version 8.0.0 - Generic host for .NET applications
• Microsoft.Extensions.Configuration: Version 9.0.3 - Configuration framework
• Microsoft.Extensions.Logging.Console: Version 8.0.1 - Console logging provider
• Serilog.Extensions.Logging: Version 9.0.1 - Serilog integration with Microsoft.Extensions.Logging
• Serilog.Sinks.File: Version 7.0.0 - Serilog file logging sink
• System.CommandLine: Version 2.0.0-beta4.22272.1 - Command-line argument parsing
• System.CommandLine.NamingConventionBinder: Version 2.0.0-beta4.22272.1 - Command-line binding support
• Hl7.Fhir.R4: Firely SDK version - FHIR R4 POCOs and serialization support

Dev Start

During development, pre-releases will appear on Firely's GitHub Package feed. To use these packages you must add https://nuget.pkg.github.com/FirelyTeam/index.json to your NuGet sources:

• Get a Personal Access token (PAT) from github.com with scope read:packages

• Next open a console on your machine and run dotnet nuget add source --name github --username <USERNAME> --password <PAT> https://nuget.pkg.github.com/FirelyTeam/index.json

USERNAME: your username on GitHub PAT: your Personal access token with at least the scope read:packages

Further information can be found in docs/getting-started.md.

Support

We actively monitor the issues coming in through the GitHub repository at https://github.com/FirelyTeam/firely-cql-sdk/issues. You are welcome to register your bugs and feature suggestions there. For questions and broader discussions, we use the .NET FHIR Implementers chat and CQL chat on Zulip.

Contributing

We are welcoming contributions!

If you want to participate in this project, we're using Git Flow for our branch management. Please submit PRs with changes against the develop branch.