# Functions
ParseType returns the canonical package type given a string key.
# Constants
Apache Ant (https://ant.apache.org).
Bazel (https://bazel.build/).
Bower (https://bower.io).
Buck (https://buckbuild.com).
Carthage (https://github.com/Carthage/Carthage).
Clojure (https://clojure.org).
Cocoapods (https://cocoapods.org).
Composer (https://getcomposer.org).
Debian (https://manpages.debian.org/stretch/dpkg/dpkg.1.en.html).
git.
dep (https://github.com/golang/dep), glide (https://github.com/Masterminds/glide), godep (https://github.com/tools/godep), govendor (experimental, https://github.com/kardianos/govendor), vndr (https://github.com/LK4D4/vndr), gomodules (https://github.com/golang/go/wiki/Modules).
Gradle (https://gradle.org).
Haskell with cabal-install (https://www.haskell.org/cabal/) or stack (https://www.haskellstack.org/).
Maven (https://maven.apache.org).
NPM (https://www.npmjs.com), Yarn (https://yarnpkg.com).
NuGet (https://www.nuget.org).
OkBuck (https://github.com/uber/okbuck).
Pip (https://pip.pypa.io), Pipenv (https://pipenv.readthedocs.io/en/latest/).
Unsupported languages.
RPM https://rpm.org/.
Bundler (https://bundler.io).
Cargo (https://github.com/rust-lang/cargo).
SBT (https://www.scala-sbt.org).
# Structs
An Author is a package author.
TODO: Implement file-level granularity?.
An ID uniquely identifies a package.
An Import is a combination of a (potentially unresolved) dependency target and the exact resolved pkg.ID of the dependency.
A Package represents a single package at a semantic level.
# Type aliases
A LicenseExpr is a raw string containing a SPDX-like license expression.
The Type of a Package indicates the ecosystem of the package.