add setup.py && update README.md

sphinxcontrib/d2lang/__init__.py

@@ -0,0 +1,20 @@
+from sphinx.application import Sphinx
+
+from .d2lang import D2langDirective
+
+from typing import Any, Dict, List, Tuple
+
+from shutil import which
+
+__version__ = (0, 0, 1)
+
+def setup(application: Sphinx) -> Dict[str, Any]:
+    """
+    setup extension.
+    """
+    if which('d2'):
+        application.add_directive('d2lang', D2langDirective)
+        return {"version": __version__, "parallel_read_safe": True}
+    else:
+        print("d2 binary not found in $PATH")
+        raise

sphinxcontrib/d2lang/d2lang.py

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+from docutils import nodes
+
+from docutils.parsers.rst import Directive, directives
+from sphinx.util.docutils import SphinxDirective
+
+from shutil import which
+from pathlib import Path
+import shlex
+import subprocess
+import tempfile
+import uuid
+
+class D2langDirective(SphinxDirective):
+    required_arguments = 0
+    has_content = True
+    optional_arguments = 3
+    option_spec = {
+        'layout': directives.unchanged_required,
+        'filename': directives.unchanged_required,
+    }
+    def run(self):
+        d2_bin = which('d2')
+        srcdir = self.state.document.settings.env.srcdir
+        diag_source = self.content
+        if 'filename' in self.options:
+            output_fname = self.options.get('filename')
+        else:
+            output_fname = "d2lang_svg/" + str(uuid.uuid4()) + ".svg"
+        if 'layout' in self.options:
+            layout = self.options.get('layout')
+        else:
+            layout = 'dagre'
+        if self.arguments:
+            path = Path(srcdir + '/' + self.arguments[0])
+            if path.is_file():
+                build_svg(
+                    srcdir + '/' + self.arguments[0],
+                    srcdir,
+                    output_fname,
+                    layout
+                )
+            else:
+                raise
+        else:
+            with tempfile.NamedTemporaryFile() as fp:
+                for line in self.content.data:
+                    fp.write(bytes(line,'utf-8'))
+                    fp.write(bytes('\n','utf-8'))
+                fp.seek(0)
+                build_svg(fp.name, srcdir, output_fname, layout)
+        image_node = nodes.image(uri=output_fname)
+        return [image_node]
+
+def build_svg(diag_src, out_dir, filename, layout):
+    d2_bin = which('d2')
+    cmd_line = '%s -l %s %s %s' % (d2_bin, layout, diag_src, out_dir + "/" + filename)
+    args = shlex.split(cmd_line)
+    subprocess.run(args)
+    return True

sphinxcontrib/requirements.txt

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+sphinx
+docutils