Merge datatype/language into node

This moves closer to the sord API, and is more convenient in most cases.

3 files changed, 42 insertions, 14 deletions

diff --git a/include/serd/node.h b/include/serd/node.h
index b95891c9..4aa4ec0a 100644
--- a/include/serd/node.h
+++ b/include/serd/node.h
@@ -84,8 +84,10 @@ typedef enum {
 
 /// Node flags, which ORed together make a #SerdNodeFlags
 typedef enum {
-  SERD_HAS_NEWLINE = 1U << 0U, ///< Contains line breaks ('\\n' or '\\r')
-  SERD_HAS_QUOTE   = 1U << 1U, ///< Contains quotes ('"')
+  SERD_HAS_NEWLINE  = 1U << 0U, ///< Contains line breaks ('\\n' or '\\r')
+  SERD_HAS_QUOTE    = 1U << 1U, ///< Contains quotes ('"')
+  SERD_HAS_DATATYPE = 1U << 2U, ///< Literal node has datatype
+  SERD_HAS_LANGUAGE = 1U << 3U, ///< Literal node has language
 } SerdNodeFlag;
 
 /// Bitwise OR of #SerdNodeFlag values
@@ -112,6 +114,17 @@ serd_new_substring(SerdNodeType              type,
                    size_t                    len);
 
 /**
+   Create a new literal node from `str`.
+
+   Either `datatype` or `lang` can be given, but not both, unless `datatype` is
+   rdf:langString in which case it is ignored.
+*/
+SERD_API SerdNode* SERD_ALLOCATED
+serd_new_literal(const char* SERD_NONNULL  str,
+                 const char* SERD_NULLABLE datatype,
+                 const char* SERD_NULLABLE lang);
+
+/**
    Create a new URI node from a parsed URI.
 */
 SERD_API SerdNode* SERD_ALLOCATED
@@ -228,6 +241,26 @@ SERD_API SerdURIView
 serd_node_uri_view(const SerdNode* SERD_NONNULL node);
 
 /**
+   Return the optional datatype of a literal node.
+
+   The datatype, if present, is always a URI, typically something like
+   <http://www.w3.org/2001/XMLSchema#boolean>.
+*/
+SERD_PURE_API const SerdNode* SERD_NULLABLE
+serd_node_datatype(const SerdNode* SERD_NONNULL node);
+
+/**
+   Return the optional language tag of a literal node.
+
+   The language tag, if present, is a well-formed BCP 47 (RFC 4647) language
+   tag like "en-ca".  Note that these must be handled case-insensitively, for
+   example, the common form "en-CA" is valid, but lowercase is considered
+   canonical here.
+*/
+SERD_PURE_API const SerdNode* SERD_NULLABLE
+serd_node_language(const SerdNode* SERD_NONNULL node);
+
+/**
    @}
    @defgroup serd_node_operators Operators
    @{
diff --git a/include/serd/sink.h b/include/serd/sink.h
index 97b47a2f..702197d5 100644
--- a/include/serd/sink.h
+++ b/include/serd/sink.h
@@ -39,15 +39,12 @@ typedef SerdStatus (*SerdPrefixFunc)(void* SERD_NULLABLE          handle,
 
    Called for every RDF statement in the serialisation.
 */
-typedef SerdStatus (*SerdStatementFunc)(
-  void* SERD_NULLABLE           handle,
-  SerdStatementFlags            flags,
-  const SerdNode* SERD_NULLABLE graph,
-  const SerdNode* SERD_NONNULL  subject,
-  const SerdNode* SERD_NONNULL  predicate,
-  const SerdNode* SERD_NONNULL  object,
-  const SerdNode* SERD_NULLABLE object_datatype,
-  const SerdNode* SERD_NULLABLE object_lang);
+typedef SerdStatus (*SerdStatementFunc)(void* SERD_NULLABLE           handle,
+                                        SerdStatementFlags            flags,
+                                        const SerdNode* SERD_NULLABLE graph,
+                                        const SerdNode* SERD_NONNULL  subject,
+                                        const SerdNode* SERD_NONNULL  predicate,
+                                        const SerdNode* SERD_NONNULL  object);
 
 /**
    Sink function for anonymous node end markers.
diff --git a/include/serd/writer.h b/include/serd/writer.h
index 66c3d338..3327c1b9 100644
--- a/include/serd/writer.h
+++ b/include/serd/writer.h
@@ -139,9 +139,7 @@ serd_writer_write_statement(SerdWriter* SERD_NONNULL      writer,
                             const SerdNode* SERD_NULLABLE graph,
                             const SerdNode* SERD_NONNULL  subject,
                             const SerdNode* SERD_NONNULL  predicate,
-                            const SerdNode* SERD_NONNULL  object,
-                            const SerdNode* SERD_NULLABLE datatype,
-                            const SerdNode* SERD_NULLABLE lang);
+                            const SerdNode* SERD_NONNULL  object);
 
 /**
    Mark the end of an anonymous node's description.