1 files changed, 51 insertions, 0 deletions
diff --git a/asciidoc/attrs.py b/asciidoc/attrs.py
new file mode 100644
index 0000000..f61b62b
--- /dev/null
+++ b/asciidoc/attrs.py
@@ -0,0 +1,51 @@
+import re
+import typing
+
+from .utils import get_args, get_kwargs
+
+
+def parse_attributes(attrs: str, output_dict: typing.Dict) -> None:
+    """Update a dictionary with name/value attributes from the attrs string.
+    The attrs string is a comma separated list of values and keyword name=value
+    pairs. Values must precede keywords and are named '1','2'... The entire
+    attributes list is named '0'. If keywords are specified string values must
+    be quoted. Examples:
+
+    attrs: ''
+    output_dict: {}
+
+    attrs: 'hello,world'
+    output_dict: {'2': 'world', '0': 'hello,world', '1': 'hello'}
+
+    attrs: '"hello", planet="earth"'
+    output_dict: {'planet': 'earth', '0': '"hello", planet="earth"', '1': 'hello'}
+    """
+    if not attrs:
+        return
+    output_dict['0'] = attrs
+    # Replace line separators with spaces so line spanning works.
+    s = re.sub(r'\s', ' ', attrs)
+    d = {}
+    try:
+        d.update(get_args(s))
+        d.update(get_kwargs(s))
+        for v in list(d.values()):
+            if not (isinstance(v, str)
+                    or isinstance(v, int) or isinstance(v, float) or v is None):
+                raise Exception
+    except Exception:
+        s = s.replace('"', '\\"')
+        s = s.split(',')
+        s = ['"' + x.strip() + '"' for x in s]
+        s = ','.join(s)
+        try:
+            d = {}
+            d.update(get_args(s))
+            d.update(get_kwargs(s))
+        except Exception:
+            return  # If there's a syntax error leave with {0}=attrs.
+        for k in list(d.keys()):  # Drop any empty positional arguments.
+            if d[k] == '':
+                del d[k]
+    output_dict.update(d)
+    assert len(d) > 0