digraph: refactor allpaths to print an adjacency list

Refactors allpaths to print an adjacency list from "from" to "to", instead of
just the nodes. This allows other tools like modgraphviz to print the subgraph.
For example, the following command:

    cd $GOPATH/src/cloud.google.com/go && \
    go mod graph | \
    digraph allpaths cloud.google.com/go golang.org/x/text@v0.3.2 | \
    modgraphviz | \
    dot -Tpng -o graph.png

Generates the following graph.png: https://user-images.githubusercontent.com/3584893/60481727-df0a8680-9c4b-11e9-8df9-c581d599edd1.png

Also splits out the allpaths tests into their own test, and adds many test
cases.

This is a breaking change. The previous behavior returned vertices; now it
returns edges. If you relied on the previous behavior, use:

    my-application | digraph allpaths <from> <to> | digraph nodes

Change-Id: I2eb7c377f5fe1e1e90c5b74eaa78d5211192bb2a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/184337
Reviewed-by: Alan Donovan <adonovan@google.com>
2 files changed
tree: 06c37bf0395641ddfc25ca1d4f9aaacfebfce0aa
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. go.mod
  21. go.sum
  22. LICENSE
  23. PATENTS
  24. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.