5.1 Introduction to documentation work (LilyPond Contributor’s Guide)

### 5.1 Introduction to documentation work

Our documentation tries to adhere to our documentation policy (see Documentation policy). This policy contains a few items which may seem odd. One policy in particular is often questioned by potential contributors: we do not repeat material in the Notation Reference, and instead provide links to the “definitive” presentation of that information. Some people point out, with good reason, that this makes the documentation harder to read: if we repeated certain information in relevant places, readers would be less likely to miss that information.

That reasoning is sound, but we have two counter-arguments. First, the Notation Reference – one of five manuals for users to read – is already over 900 pages long. If we repeated material, we would easily need a few hundred pages more! Second, and much more importantly, LilyPond is an evolving project. New features are added, bugs are fixed, and bugs are discovered and documented. If features are discussed in multiple places, the documentation team must find every instance. Since the manual is so large, it is impossible for one person to have the location of every piece of information memorized, so any attempt to update the documentation will invariably omit a few places. This second concern is not at all theoretical; the documentation used to be plagued with inconsistent information.

If the documentation were targeted for a specific version – say, LilyPond 2.24.1 – and we had unlimited resources to spend on documentation, then we could avoid this second problem. However, since LilyPond evolves (and that is a very good thing!), and since we have quite limited resources, this policy remains in place.

A few other policies (such as avoiding the use of tweaks in the main portion of Notation Reference chapters 1 and 2) may also seem counter-intuitive, but they also stem from attempting to find the most effective use of limited documentation help.

Before undertaking any large documentation work, contributors are encouraged to contact the lilypond-devel@gnu.org mailing list.

#### LilyPond Contributor’s Guide v2.26.0 (stable-branch).

- 1 Introduction to contributing
  - 1.1 Help us
  - 1.2 Overview of work flow
  - 1.3 Summary for experienced developers
  - 1.4 Mentors
- 2 Quick start
  - 2.1 LilyDev
    - Installing LilyDev in VirtualBox
    - Configuring LilyDev in VirtualBox
  - 2.2 Compiling with LilyDev
  - 2.3 Now start work!
- 3 Working with source code
  - 3.1 Setting up
    - 3.1.1 Installing Git
    - 3.1.2 Creating a GitLab account and setting up SSH
    - 3.1.3 Cloning and forking the repository
    - 3.1.4 Configuring Git
  - 3.2 Git cheat sheet
  - 3.3 Lifecycle of a merge request
    - 3.3.1 Uploading a patch for review
    - 3.3.2 Automated testing
    - 3.3.3 Patch countdown
    - 3.3.4 Merging to master
    - 3.3.5 Abandoned patches
  - 3.4 Writing good commit messages
  - 3.5 Commit access
  - 3.6 Further Git documentation resources
  - 3.7 Repository directory structure
- 4 Compiling
  - 4.1 Overview of compiling
  - 4.2 Requirements
    - 4.2.1 Requirements for running LilyPond
    - 4.2.2 Requirements for compiling LilyPond
      - Fedora
      - Linux Mint
      - OpenSUSE
      - Ubuntu
      - Other
    - 4.2.3 Requirements for building documentation
  - 4.3 Getting the source code
  - 4.4 Configuring `make`
    - 4.4.1 Build modes
    - 4.4.2 Running `autogen.sh`
    - 4.4.3 Running `configure`
      - Configuration options
      - Checking build dependencies
      - Configuring target directories
  - 4.5 Compiling LilyPond
    - 4.5.1 Using `make`
    - 4.5.2 Saving time with the `-j` option
    - 4.5.3 Useful `make` variables
  - 4.6 Post-compilation options
    - 4.6.1 Installing LilyPond from a local build
    - 4.6.2 Generating documentation
      - Documentation editor’s edit/compile cycle
      - Building documentation
      - Building a single document
      - Saving time with `CPU_COUNT`
      - Installing documentation
      - Building documentation without compiling
    - 4.6.3 Testing LilyPond binary
  - 4.7 Problems
  - 4.8 Concurrent stable and development versions
    - 4.8.1 Replacing the notation fonts in development versions
  - 4.9 Build system
- 5 Documentation work
  - 5.1 Introduction to documentation work
  - 5.2 `\version` in documentation files
  - 5.3 Documentation suggestions
  - 5.4 Texinfo introduction and usage policy
    - 5.4.1 Texinfo introduction
    - 5.4.2 Documentation files
    - 5.4.3 Sectioning commands
    - 5.4.4 Menus
    - 5.4.5 LilyPond formatting
    - 5.4.6 Text formatting
    - 5.4.7 Syntax survey
      - Comments
      - Cross-references
      - External links
      - Fixed-width font
      - Indexing
      - Lists
      - Special characters
      - Miscellany
    - 5.4.8 Other text concerns
  - 5.5 Documentation policy
    - 5.5.1 Books
    - 5.5.2 Section organization
    - 5.5.3 Checking cross-references
    - 5.5.4 General writing
    - 5.5.5 Technical writing style
  - 5.6 Tips for writing documentation
    - 5.6.1 Working on subsections
    - 5.6.2 Searching
  - 5.7 Scripts to ease documentation work
    - 5.7.1 Building only one section of the documentation
    - 5.7.2 Updating documentation with `convert-ly`
  - 5.8 Documentation strings in the Internals Reference
  - 5.9 Translating the documentation
    - 5.9.1 Getting started with documentation translation
      - Translation requirements
      - Which documentation can be translated
      - Starting translation in a new language
    - 5.9.2 Documentation translation details
      - Files to be translated
      - Translating the website and other Texinfo documentation
      - Adding a Texinfo manual
    - 5.9.3 Documentation translation maintenance
      - Check state of translation
      - Updating documentation translation
      - Updating translation committishes
      - Maintaining without updating translations
    - 5.9.4 Technical background
- 6 Website work
  - 6.1 Introduction to website work
  - 6.2 Uploading website
  - 6.3 Debugging website and docs locally
  - 6.4 Translating the website
- 7 LilyPond Wiki work
  - 7.1 Introduction to the LilyPond Wiki
  - 7.2 Adding and editing snippets
  - 7.3 Snippet administration
  - 7.4 The `makelsr.pl` script
  - 7.5 LilyPond Wiki to Git
- 8 Issues
  - 8.1 Introduction to issues
  - 8.2 Triaging bugs
  - 8.3 Issue classification
  - 8.4 Adding issues to the tracker
- 9 Regression tests
  - 9.1 Introduction to regression tests
  - 9.2 Precompiled regression tests
  - 9.3 Compiling regression tests
  - 9.4 Regtest comparison
  - 9.5 Pixel-based regtest comparison
  - 9.6 Finding the cause of a regression
  - 9.7 MusicXML tests
- 10 Programming work
  - 10.1 Overview of LilyPond architecture
  - 10.2 LilyPond programming languages
  - 10.3 Programming without compiling
  - 10.4 Finding functions
  - 10.5 Code style
    - 10.5.1 Languages
    - 10.5.2 Filenames
    - 10.5.3 Code formatting
    - 10.5.4 Naming Conventions
    - 10.5.5 Broken code
    - 10.5.6 Code comments
    - 10.5.7 Handling errors
    - 10.5.8 Localization
  - 10.6 Warnings, Errors, Progress and Debug Output
  - 10.7 Debugging LilyPond
    - 10.7.1 Debugging overview
    - 10.7.2 Debugging C++ code
    - 10.7.3 Debugging Scheme code
    - 10.7.4 Debugging scoring algorithms
    - 10.7.5 Debugging skylines
  - 10.8 Tracing object relationships
  - 10.9 Tracing processing time
  - 10.10 Adding or modifying features
    - 10.10.1 Write the code
    - 10.10.2 Write regression tests
    - 10.10.3 Write convert-ly rule
    - 10.10.4 Automatically update documentation
    - 10.10.5 Manually update documentation
    - 10.10.6 Edit changes.tely
    - 10.10.7 Verify successful build
    - 10.10.8 Verify regression tests
    - 10.10.9 Post patch for comments
    - 10.10.10 Push patch
    - 10.10.11 Closing the issues
  - 10.11 Iterator tutorial
  - 10.12 Engraver tutorial
    - 10.12.1 Useful methods for information processing
    - 10.12.2 Translation process
    - 10.12.3 Listening to music events
    - 10.12.4 Acknowledging grobs
    - 10.12.5 Engraver declaration/documentation
  - 10.13 Callback tutorial
  - 10.14 Understanding pure properties
    - 10.14.1 Purity in LilyPond
    - 10.14.2 Writing a pure function
    - 10.14.3 How purity is defined and stored
    - 10.14.4 Where purity is used
    - 10.14.5 Case studies
    - 10.14.6 Debugging tips
  - 10.15 LilyPond scoping
  - 10.16 Regular expressions
  - 10.17 Scheme->C interface
    - 10.17.1 Comparison
    - 10.17.2 Conversion
  - 10.18 Garbage collection for dummies
  - 10.19 LilyPond miscellany
    - 10.19.1 Spacing algorithms
    - 10.19.2 Info from Han-Wen email
    - 10.19.3 Music functions and Guile debugging
    - 10.19.4 Articulations on EventChord
- 11 Release work
  - 11.1 Development phases
  - 11.2 Release checklist
  - 11.3 Major release checklist
- 12 Modifying the Emmentaler font
  - 12.1 Overview of the Emmentaler font
  - 12.2 Font creation tools
  - 12.3 Adding a new font section
  - 12.4 Adding a new glyph
  - 12.5 Building the changed font
  - 12.6 METAFONT formatting rules
- 13 Administrative policies
  - 13.1 LilyPond is GNU Software
  - 13.2 Environment variables
  - 13.3 Performing yearly copyright update (“grand-replace”)
- Appendix A GNU Free Documentation License