Package development process
Encyclopedia
A Software Package development process is a system for developing software packages
. Packages make it easier to reuse and share code, e.g., via a software repository
. A formal system for package checking can help expose bugs, thereby potentially making it easier to produce trustworty software (Chambers' prime directive). This in turn can help improve productivity for people who produce and use software.
or R
, bundled with documentation. For many programming languages, there are software repositories
where people share such packages.
For example, a Python
package combines documentation, code and initial set up and possibly examples that could be used as unit tests in a single file with a "py" extension.
By contrast, an R
package has documentation with examples in files separate from the code, possibly bundled with other material such as sample data sets and introductory vignettes. The source code for an R package is contained in a directory with a master "description" file and separate subdirectories for documentation, code, optional data sets suits for unit or regression testing, and perhaps others. A formal package compilation process
checks for errors of various types. This includes checking for syntax errors on both the documentation markup language and the code as well as comparing the arguments between documentation and code. Examples in the documentation are tested and produce error messages if they fail. This can be used as a primitive form of unit testing; more formal unit tests and regression testing
can be included. This can improve software development productivity by making it easier to find bugs as the code is being developed. In addition, the documentation makes it easier to share code with others. It also makes it easier for a developer to use code written months or even years earlier. Routine checks are made of packages contributed to the R software repository CRAN (the Comprehensive R Archive Network) and under development in companion open-source collaborative development web site, R-Forge . These checks compile the packages repeatedly on different platforms under different versions of the core R language. The results are made available to package maintainers. In this way, package contributors become aware of problems they might otherwise never encounter themselves, because they otherwise would not have easy access to those alternative test results.
An interesting research question would be to compare the quality of contributions to different software repositories
and try to relate that to features of the package development process, i.e., the degree of formality and enforcement of standards for documentation, code, and testing and to the rate of growth of usage of contributed software.
Software package (installation)
In package management systems, which are commonly used with Linux-based operating systems, a package is a specific piece of software which the system can install and uninstall....
. Packages make it easier to reuse and share code, e.g., via a software repository
Software repository
A software repository is a storage location from which software packages may be retrieved and installed on a computer.- Discussion :Many software publishers and other organizations maintain servers on the Internet for this purpose, either free of charge or for a subscription fee...
. A formal system for package checking can help expose bugs, thereby potentially making it easier to produce trustworty software (Chambers' prime directive). This in turn can help improve productivity for people who produce and use software.
Discussion
In this context, a package is a collection of functions written for use in a single language such as PythonPython (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
or R
R (programming language)
R is a programming language and software environment for statistical computing and graphics. The R language is widely used among statisticians for developing statistical software, and R is widely used for statistical software development and data analysis....
, bundled with documentation. For many programming languages, there are software repositories
Software repository
A software repository is a storage location from which software packages may be retrieved and installed on a computer.- Discussion :Many software publishers and other organizations maintain servers on the Internet for this purpose, either free of charge or for a subscription fee...
where people share such packages.
For example, a Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
package combines documentation, code and initial set up and possibly examples that could be used as unit tests in a single file with a "py" extension.
By contrast, an R
R (programming language)
R is a programming language and software environment for statistical computing and graphics. The R language is widely used among statisticians for developing statistical software, and R is widely used for statistical software development and data analysis....
package has documentation with examples in files separate from the code, possibly bundled with other material such as sample data sets and introductory vignettes. The source code for an R package is contained in a directory with a master "description" file and separate subdirectories for documentation, code, optional data sets suits for unit or regression testing, and perhaps others. A formal package compilation process
checks for errors of various types. This includes checking for syntax errors on both the documentation markup language and the code as well as comparing the arguments between documentation and code. Examples in the documentation are tested and produce error messages if they fail. This can be used as a primitive form of unit testing; more formal unit tests and regression testing
Regression testing
Regression testing is any type of software testing that seeks to uncover new errors, or regressions, in existing functionality after changes have been made to a system, such as functional enhancements, patches or configuration changes....
can be included. This can improve software development productivity by making it easier to find bugs as the code is being developed. In addition, the documentation makes it easier to share code with others. It also makes it easier for a developer to use code written months or even years earlier. Routine checks are made of packages contributed to the R software repository CRAN (the Comprehensive R Archive Network) and under development in companion open-source collaborative development web site, R-Forge . These checks compile the packages repeatedly on different platforms under different versions of the core R language. The results are made available to package maintainers. In this way, package contributors become aware of problems they might otherwise never encounter themselves, because they otherwise would not have easy access to those alternative test results.
An interesting research question would be to compare the quality of contributions to different software repositories
Software repository
A software repository is a storage location from which software packages may be retrieved and installed on a computer.- Discussion :Many software publishers and other organizations maintain servers on the Internet for this purpose, either free of charge or for a subscription fee...
and try to relate that to features of the package development process, i.e., the degree of formality and enforcement of standards for documentation, code, and testing and to the rate of growth of usage of contributed software.
See also
- Package management systemPackage management systemIn software, a package management system, also called package manager, is a collection of software tools to automate the process of installing, upgrading, configuring, and removing software packages for a computer's operating system in a consistent manner...
for combining software packages in different languages into an operating system. - Software repositorySoftware repositoryA software repository is a storage location from which software packages may be retrieved and installed on a computer.- Discussion :Many software publishers and other organizations maintain servers on the Internet for this purpose, either free of charge or for a subscription fee...
for collections of packages to share.