doc: introduce a synopsis custom paragraph attribute

In order to follow the common manpage usage, the synopsis of the
commands needs to be heavily typeset. A first try was performed with
using native markup, but it turned out to make the document source
almost unreadable, difficult to write and prone to mistakes with
unwanted Asciidoc's role attributes.

In order to both simplify the writer's task and obtain a consistant
typesetting in the synopsis, a custom 'synopsis' paragraph type is
created and the backends of asciidoc and asciidoctor take in charge to
correctly add the required typesetting.

Signed-off-by: Jean-Noël Avila <[email protected]>

Documentation/asciidoc.conf

@@ -57,3 +57,15 @@ git-relative-html-prefix=
 [linkgit-inlinemacro]
 <a href="{git-relative-html-prefix}{target}.html">{target}{0?({0})}</a>
 endif::backend-xhtml11[]
+
+ifdef::backend-docbook[]
+ifdef::doctype-manpage[]
+[paradef-default]
+synopsis-style=template="verseparagraph",filter="sed -E 's!([\[ |()>]|^|\])([-=a-zA-Z0-9:+.]+)!\\1<literal>\\2</literal>!g;s!&lt;[-a-zA-Z0-9.]+&gt;!<emphasis>\\0</emphasis>!g'"
+endif::doctype-manpage[]
+endif::backend-docbook[]
+
+ifdef::backend-xhtml11[]
+[paradef-default]
+synopsis-style=template="verseparagraph",filter="sed -E 's!([\[ |()>]|^|\])([-=a-zA-Z0-9:+.]+)!\\1<code>\\2</code>!g;s!&lt;[-a-zA-Z0-9.]+&gt;!<em>\\0</em>!g'"
+endif::backend-xhtml11[]

Documentation/asciidoctor-extensions.rb

@@ -39,10 +39,27 @@ def process document, output
         output
       end
     end
+
+    class SynopsisBlock < Asciidoctor::Extensions::BlockProcessor
+
+      use_dsl
+      named :synopsis
+      parse_content_as :simple
+
+      def process parent, reader, attrs
+        outlines = reader.lines.map do |l|
+          l.gsub(/([\[\] |()>]|^)([-a-zA-Z0-9:+=.]+)/, '\\1{empty}`\\2`{empty}')
+           .gsub(/(<[-a-zA-Z0-9.]+>)/, '__\\1__')
+           .gsub(']', ']{empty}')
+        end
+        create_block parent, :verse, outlines, attrs
+      end
+    end
   end
 end
 
 Asciidoctor::Extensions.register do
   inline_macro Git::Documentation::LinkGitProcessor, :linkgit
+  block Git::Documentation::SynopsisBlock
   postprocessor Git::Documentation::DocumentPostProcessor
 end

t/t0450-txt-doc-vs-help.sh

@@ -56,17 +56,14 @@ txt_to_synopsis () {
 	fi &&
 	b2t="$(builtin_to_txt "$builtin")" &&
 	sed -n \
-		-e '/^\[verse\]$/,/^$/ {
-			/^$/d;
-			/^\[verse\]$/d;
-			s/_//g;
-			s/++//g;
-			s/`//g;
-			s/{litdd}/--/g;
-			s/'\''\(git[ a-z-]*\)'\''/\1/g;
-
-			p;
-		}' \
+                -E '/^\[(verse|synopsis)\]$/,/^$/ {
+                        /^$/d;
+                        /^\[(verse|synopsis)\]$/d;
+                        s/\{litdd\}/--/g;
+                        s/'\''(git[ a-z-]*)'\''/\1/g;
+
+                        p;
+                }' \
 		<"$b2t" >"$out" &&
 	echo "$out"
 }