feat: add basic features

Add rendering of dot, plantuml, pikchr, roadmap, and raw SVG, from
fenced code blocks into SVG.

Sponsored-by: pep.foundation

1 files changed, 65 insertions, 0 deletions

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+# pandoc-filter-diagram -- render diagram markup in a Pandoc AST as SVG
+
+[Pandoc][] is a powerful tool for processing documents in various
+formats. It parses each of its supported input formats into an
+in-memory abstract syntax tree, and then renders any supported output
+format from such a tree. In between, it can run an arbitrary program
+to "filter" the tree, and the program can make any arbitrary changes
+to the tree.
+
+This Rust crate provides a library to render as SVG diagrams in
+various markup languages, embedded in Markdown as [fenced code blocks][]
+that are marked with the appropriate class.
+
+~~~~~~~~markdown
+# Example
+
+The following is a simplistic diagram using Graphviz dot language.
+
+~~~dot
+digraph "example" { thing -> other }
+~~~
+~~~~~~~~
+
+This crate also provides a command line program,
+`pandoc-filter-diagram`, which can be used with the Pandoc `--filter`
+command line option.
+
+## Languages
+
+The library supports the following languages:
+
+- [pikchr](https://pikchr.org/home/doc/trunk/homepage.md)
+- [Graphviz dot](https://graphviz.org/doc/info/lang.html)
+- [PlantUML](https://plantuml.com/)
+- [roadmap](https://gitlab.com/larswirzenius/roadmap)
+- [raw SVG](https://en.wikipedia.org/wiki/Scalable_Vector_Graphics)
+
+
+# Licence
+
+## The MIT License (MIT)
+
+Copyright 2019-2021  Lars Wirzenius, Daniel Silverstone
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+“Software”), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Fork this project to create your own MIT license that you can always
+link to.