Use latest skylighting; ensure no duplicate ids on code lines.

The line identifiers are built using the code block's identifier
as a prefix. If the code block has null identifier, we use
"cb1", "cb2", etc.

Closes #4031.

pandoc.cabal

@@ -320,7 +320,7 @@ library
                  tagsoup >= 0.13.7 && < 0.15,
                  base64-bytestring >= 0.1 && < 1.1,
                  zlib >= 0.5 && < 0.7,
-                 skylighting >= 0.4.2 && <0.5,
+                 skylighting >= 0.4.3 && <0.5,
                  data-default >= 0.4 && < 0.8,
                  temporary >= 1.1 && < 1.3,
                  blaze-html >= 0.5 && < 0.10,

src/Text/Pandoc/Highlighting.hs

@@ -81,12 +81,15 @@ highlight :: SyntaxMap
           -> Attr   -- ^ Attributes of the CodeBlock
           -> String -- ^ Raw contents of the CodeBlock
           -> Either String a
-highlight syntaxmap formatter (_, classes, keyvals) rawCode =
+highlight syntaxmap formatter (ident, classes, keyvals) rawCode =
   let firstNum = fromMaybe 1 (safeRead (fromMaybe "1" $ lookup "startFrom" keyvals))
       fmtOpts = defaultFormatOpts{
                   startNumber = firstNum,
                   numberLines = any (`elem`
-                        ["number","numberLines", "number-lines"]) classes }
+                        ["number","numberLines", "number-lines"]) classes,
+                  lineIdPrefix = if null ident
+                                    then mempty
+                                    else T.pack (ident ++ "-") }
       tokenizeOpts = TokenizerConfig{ syntaxMap = syntaxmap
                                     , traceOutput = False }
       classes' = map T.pack classes

src/Text/Pandoc/Writers/HTML.hs

@@ -101,6 +101,7 @@ data WriterState = WriterState
     , stHtml5        :: Bool    -- ^ Use HTML5
     , stEPUBVersion  :: Maybe EPUBVersion -- ^ EPUB version if for epub
     , stSlideVariant :: HTMLSlideVariant
+    , stCodeBlockNum :: Int     -- ^ Number of code block
     }
 
 defaultWriterState :: WriterState
@@ -108,7 +109,8 @@ defaultWriterState = WriterState {stNotes= [], stMath = False, stQuotes = False,
                                   stHighlighting = False, stSecNum = [],
                                   stElement = False, stHtml5 = False,
                                   stEPUBVersion = Nothing,
-                                  stSlideVariant = NoSlides}
+                                  stSlideVariant = NoSlides,
+                                  stCodeBlockNum = 0}
 
 -- Helpers to render HTML with the appropriate function.
 
@@ -703,6 +705,12 @@ blockToHtml _ HorizontalRule = do
   html5 <- gets stHtml5
   return $ if html5 then H5.hr else H.hr
 blockToHtml opts (CodeBlock (id',classes,keyvals) rawCode) = do
+  id'' <- if null id'
+             then do
+               modify $ \st -> st{ stCodeBlockNum = stCodeBlockNum st + 1 }
+               codeblocknum <- gets stCodeBlockNum
+               return ("cb" ++ show codeblocknum)
+             else return id'
   let tolhs = isEnabled Ext_literate_haskell opts &&
                 any (\c -> map toLower c == "haskell") classes &&
                 any (\c -> map toLower c == "literate") classes
@@ -716,7 +724,7 @@ blockToHtml opts (CodeBlock (id',classes,keyvals) rawCode) = do
                     else rawCode
       hlCode   = if isJust (writerHighlightStyle opts)
                     then highlight (writerSyntaxMap opts) formatHtmlBlock
-                            (id',classes',keyvals) adjCode
+                            (id'',classes',keyvals) adjCode
                     else Left ""
   case hlCode of
          Left msg -> do
@@ -725,7 +733,7 @@ blockToHtml opts (CodeBlock (id',classes,keyvals) rawCode) = do
            addAttrs opts (id',classes,keyvals)
              $ H.pre $ H.code $ toHtml adjCode
          Right h -> modify (\st -> st{ stHighlighting = True }) >>
-                    addAttrs opts (id',[],keyvals) h
+                    addAttrs opts (id'',[],keyvals) h
 blockToHtml opts (BlockQuote blocks) = do
   -- in S5, treat list in blockquote specially
   -- if default is incremental, make it nonincremental;

stack.yaml

@@ -9,7 +9,7 @@ packages:
 extra-deps:
 - pandoc-types-1.17.2
 - hslua-0.9.2
-- skylighting-0.4.2
+- skylighting-0.4.3
 - cmark-gfm-0.1.1
 - QuickCheck-2.10.0.1
 - tasty-quickcheck-0.9.1

test/lhs-test.html

@@ -72,9 +72,9 @@ code span.in { color: #60a0b0; font-weight: bold; font-style: italic; } /* Infor
 <h1 id="lhs-test">lhs test</h1>
 <p><code>unsplit</code> is an arrow that takes a pair of values and combines them to
 return a single value:</p>
-<pre class="sourceCode literate haskell"><code class="sourceCode haskell"><div class="sourceLine" id="1" href="#1" data-line-number="1"><span class="ot">unsplit ::</span> (<span class="dt">Arrow</span> a) <span class="ot">=&gt;</span> (b <span class="ot">-&gt;</span> c <span class="ot">-&gt;</span> d) <span class="ot">-&gt;</span> a (b, c) d</div>
+<pre class="sourceCode literate haskell" id="cb1"><code class="sourceCode haskell"><div class="sourceLine" id="cb1-1" data-line-number="cb1-1"><span class="ot">unsplit ::</span> (<span class="dt">Arrow</span> a) <span class="ot">=&gt;</span> (b <span class="ot">-&gt;</span> c <span class="ot">-&gt;</span> d) <span class="ot">-&gt;</span> a (b, c) d</div>
-<div class="sourceLine" id="2" href="#2" data-line-number="2">unsplit <span class="fu">=</span> arr <span class="fu">.</span> uncurry</div>
+<div class="sourceLine" id="cb1-2" data-line-number="cb1-2">unsplit <span class="fu">=</span> arr <span class="fu">.</span> uncurry</div>
-<div class="sourceLine" id="3" href="#3" data-line-number="3">          <span class="co">-- arr (\op (x,y) -&gt; x `op` y)</span></div></code></pre>
+<div class="sourceLine" id="cb1-3" data-line-number="cb1-3">          <span class="co">-- arr (\op (x,y) -&gt; x `op` y)</span></div></code></pre>
 <p><code>(***)</code> combines two arrows into a new arrow by running the two arrows on a
 pair of values (one arrow on the first item of the pair and one arrow on the
 second item of the pair).</p>

test/lhs-test.html+lhs

@@ -72,9 +72,9 @@ code span.in { color: #60a0b0; font-weight: bold; font-style: italic; } /* Infor
 <h1 id="lhs-test">lhs test</h1>
 <p><code>unsplit</code> is an arrow that takes a pair of values and combines them to
 return a single value:</p>
-<pre class="sourceCode literate literatehaskell"><code class="sourceCode literatehaskell"><div class="sourceLine" id="1" href="#1" data-line-number="1"><span class="ot">&gt; unsplit ::</span> (<span class="dt">Arrow</span> a) <span class="ot">=&gt;</span> (b <span class="ot">-&gt;</span> c <span class="ot">-&gt;</span> d) <span class="ot">-&gt;</span> a (b, c) d</div>
+<pre class="sourceCode literate literatehaskell" id="cb1"><code class="sourceCode literatehaskell"><div class="sourceLine" id="cb1-1" data-line-number="cb1-1"><span class="ot">&gt; unsplit ::</span> (<span class="dt">Arrow</span> a) <span class="ot">=&gt;</span> (b <span class="ot">-&gt;</span> c <span class="ot">-&gt;</span> d) <span class="ot">-&gt;</span> a (b, c) d</div>
-<div class="sourceLine" id="2" href="#2" data-line-number="2"><span class="ot">&gt;</span> unsplit <span class="fu">=</span> arr <span class="fu">.</span> uncurry</div>
+<div class="sourceLine" id="cb1-2" data-line-number="cb1-2"><span class="ot">&gt;</span> unsplit <span class="fu">=</span> arr <span class="fu">.</span> uncurry</div>
-<div class="sourceLine" id="3" href="#3" data-line-number="3"><span class="ot">&gt;</span>           <span class="co">-- arr (\op (x,y) -&gt; x `op` y)</span></div></code></pre>
+<div class="sourceLine" id="cb1-3" data-line-number="cb1-3"><span class="ot">&gt;</span>           <span class="co">-- arr (\op (x,y) -&gt; x `op` y)</span></div></code></pre>
 <p><code>(***)</code> combines two arrows into a new arrow by running the two arrows on a
 pair of values (one arrow on the first item of the pair and one arrow on the
 second item of the pair).</p>