Small caps in Bracketed Spans (#3191)

* Markdown reader: modify bracketedSpan to check small caps

* MANUAL.txt: add description on the use of `bracketed_spans` in small cap

* Improve markdown readers: bracketedSpan function EXACTLY as spanHtml

MANUAL.txt

@@ -2736,6 +2736,10 @@ To write small caps, you can use an HTML span tag:
 (The semicolon is optional and there may be space after the
 colon.) This will work in all output formats that support small caps.
 
+Alternatively, you can also use the new `bracketed_spans` syntax:
+
+    [Small caps]{style="font-variant:small-caps;"}
+
 Math
 ----
 

man/pandoc.1

@@ -3388,6 +3388,14 @@ To write small caps, you can use an HTML span tag:
 .PP
 (The semicolon is optional and there may be space after the colon.) This
 will work in all output formats that support small caps.
+.PP
+Alternatively, you can also use the new \f[C]bracketed_spans\f[] syntax:
+.IP
+.nf
+\f[C]
+[Small\ caps]{style="font\-variant:small\-caps;"}
+\f[]
+.fi
 .SS Math
 .SS Extension: \f[C]tex_math_dollars\f[]
 .PP

src/Text/Pandoc/Readers/Markdown.hs

@@ -1764,7 +1764,13 @@ bracketedSpan = try $ do
   guardEnabled Ext_bracketed_spans
   (lab,_) <- reference
   attr <- attributes
-  return $ B.spanWith attr <$> lab
+  let (ident,classes,keyvals) = attr
+  case lookup "style" keyvals of
+       Just s | null ident && null classes &&
+            map toLower (filter (`notElem` " \t;") s) ==
+                 "font-variant:small-caps"
+         -> return $ B.smallcaps <$> lab
+       _ -> return $ B.spanWith attr <$> lab
 
 regLink :: (Attr -> String -> String -> Inlines -> Inlines)
         -> F Inlines -> MarkdownParser (F Inlines)