npm package: @microsoft/powerquery-parser
Description: A parser for the Power Query/M formula language.
Author: Microsoft
Latest version: 0.19.0

# powerquery-parser

[![Build Status](https://dev.azure.com/ms/powerquery-parser/_apis/build/status/microsoft.powerquery-parser?branchName=master)](https://dev.azure.com/ms/powerquery-parser/_build/latest?definitionId=134&branchName=master)

A parser for the [Power Query/M](https://docs.microsoft.com/en-us/power-query/) language, written in TypeScript. Designed to be consumed by other projects.

## How to use

The most common way to consume the project is to interact with the helper functions found in [taskUtils.ts](src/powerquery-parser/task/taskUtils.ts). There are all-in-one functions, such as `tryLexParse`, which does a full pass on a given document. There are also incremental functions, such as `tryLex` and `tryParse`, which perform one step at a time. Minimal code samples can be found in [example.ts](src/example.ts).

## Related projects

- [powerquery-formatter](https://github.com/microsoft/powerquery-formatter): A code formatter for Power Query which is bundled in the VSCode extension.
- [powerquery-language-services](https://github.com/microsoft/powerquery-language-services): A high level library that wraps the parser for external projects, such as the VSCode extension. Includes features such as Intellisense.
- [vscode-powerquery](https://github.com/microsoft/vscode-powerquery): The VSCode extension for Power Query language support.
- [vscode-powerquery-sdk](https://github.com/microsoft/vscode-powerquery-sdk): The VSCode extension for Power Query connector SDK.

## Things to note

### Parser

The parser started off as a naive recursive descent parser with limited backtracking. It mostly followed the [official specification](https://docs.microsoft.com/en-us/powerquery-m/power-query-m-language-specification) released in October 2016. Deviations from the specification should be marked down in [specification.md](specification.md). A combinatorial parser has since been added which uses the naive parser as its base.

### Style

This project uses [prettier](https://github.com/prettier/prettier) as the primary source of style enforcement. Additional style requirements are located in [style.md](style.md).

## How to build

- Install NodeJS
- `npm install`
- `npm run-script build`

## How to run tests

- Install NodeJS
- `npm install`
- `npm test`

## Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a
Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide
a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions
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This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.