PackageManager history

• Before 2018: Install new packages by hand
  • download, extract, autoconf, configure, make
• PackageManager started in GAP Days Fall 2018
• PackageManager 1.6.2 released yesterday

Current functionality

• Install/remove packages in one line
• Handles dependencies
• Compiles automatically
• Allows multiple sources
  • Package name
  • Archive URL
  • Version control repo
  • PackageInfo.g file

Current problems

1. Uses rudimentary package list
2. Distracting function names
3. Messy system of options/interactivity

Problem 1. Package list

• Current package list: a csv file of package names with links to PackageInfo files
  • Only retrieves latest released version
  • Need to download to discover dependencies
  • No central check for new versions

New package list

• Plan: start using gap-system/PackageDistro
  • Structured json with all data from PackageInfo files
  • Accepted after careful checking
  • latest as well as a version for each GAP release
• Advantages:
  • Single resource (110kB) with all required info
  • Can be cached
  • Stability
  • Trivial to track release for a GAP version

Problem 2. Function names

• PackageManager provides InstallPackage, which dispatches to:
  • InstallPackageFromName
  • InstallPackageFromHg
  • InstallPackageFromArchive
  • InstallPackageFromInfo
  • InstallPackageFromGit
• Each has its own argument-checking, options and bugs
• These all call each other internally
• We also have UpdatePackage which does the same thing

Simpler function names

• InstallPackageFrom* are already deprecated for users
• Make UpdatePackage a synonym
• Use InstallPackage for everything

Problem 3. Options/interactivity

Some use of interactivity

gap> UpdatePackage("io");
#I  io version 4.6.0 will be installed, replacing 4.5.4
#I  Saved archive to /tmp/tm7r5Ug7/io-4.6.0.tar.gz
Remove old version of io at /home/user/.gap/pkg/io-4.5.4 ? [y/N] y
true

Some use of options

InstallPackage("digraphs" : keepDirectory);

Some use of optional parameters

InstallPackage("example", true);

Some use of global variables

PKGMAN_SetCustomPackageDir("~/Desktop/gap/pkg");

New options records

• Introduce cascading system of options records
• On calling a function, behaviour is determined by:
  1. Options record passed to function
  2. Global options record configurable by user
  3. Default options

gap> SetPackageManagerOption("distroVersion", "latest");
gap> SetPackageManagerOption("interactive", false);
gap> InstallPackage("semigroups", rec(version := "5.6.0"));

• Some behaviour interactive by default
  • Option to disable interactivity entirely

How does that sound?

• Work has started in dev-2.0 branch
• Not too late to change decisions

PackageManager

• How to use: https://gap-packages.github.io/PackageManager/
• Suggestions: https://github.com/gap-packages/PackageManager/issues
• Contributions: https://github.com/gap-packages/PackageManager/pulls
• Talk to me after!