Org reader: support Pandocs citation extension

Citations are defined via the "normal citation" syntax used in markdown,
with the sole difference that newlines are not allowed between "[...]".
This is for consistency, as org-mode generally disallows newlines
between square brackets.

The extension is turned on by default and can be turned off via the
default syntax-extension mechanism, i.e. by specifying "org-citation" as
the input format.
Move `citeKey` from Readers.Markdown into Parsing

The function can be used by other readers, so it is made accessible for
all parsers.

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/Tests/Readers/Org.hs b/tests/Tests/Readers/Org.hs
index 4ef7a7731..ca97ba348 100644
--- a/tests/Tests/Readers/Org.hs
+++ b/tests/Tests/Readers/Org.hs
@@ -225,6 +225,28 @@ tests =
                              ]
                            )
                            "echo 'Hello, World'")
+
+      , "Citation" =:
+          "[@nonexistent]" =?>
+          let citation = Citation
+                         { citationId = "nonexistent"
+                         , citationPrefix = []
+                         , citationSuffix = []
+                         , citationMode = NormalCitation
+                         , citationNoteNum = 0
+                         , citationHash = 0}
+          in (para $ cite [citation] "[@nonexistent]")
+
+      , "Citation containing text" =:
+          "[see @item1 p. 34-35]" =?>
+          let citation = Citation
+                         { citationId = "item1"
+                         , citationPrefix = [Str "see"]
+                         , citationSuffix = [Space ,Str "p.",Space,Str "34-35"]
+                         , citationMode = NormalCitation
+                         , citationNoteNum = 0
+                         , citationHash = 0}
+          in (para $ cite [citation] "[see @item1 p. 34-35]")
       ]
 
   , testGroup "Meta Information" $