Add numeric node construction and access API

1 files changed, 63 insertions, 1 deletions

diff --git a/src/node.c b/src/node.c
index db183fc0..f071fc97 100644
--- a/src/node.c
+++ b/src/node.c
@@ -276,6 +276,68 @@ serd_new_curie(const SerdStringView str)
   return serd_new_simple_node(SERD_CURIE, str);
 }
 
+ExessVariant
+serd_node_get_value_as(const SerdNode* const node,
+                       const ExessDatatype   value_type)
+{
+  const SerdNode* const datatype_node = serd_node_datatype(node);
+
+  const ExessDatatype node_type =
+    datatype_node ? exess_datatype_from_uri(serd_node_string(datatype_node))
+                  : EXESS_NOTHING;
+
+  if (!node_type) {
+    // No datatype, assume it matches and try reading the value directly
+    ExessVariant      v = exess_make_nothing(EXESS_SUCCESS);
+    const ExessResult r =
+      exess_read_variant(&v, value_type, serd_node_string(node));
+
+    return r.status ? exess_make_nothing(r.status) : v;
+  }
+
+  // Read the value from the node
+  ExessVariant      v = exess_make_nothing(EXESS_SUCCESS);
+  const ExessResult r =
+    exess_read_variant(&v, node_type, serd_node_string(node));
+
+  // Coerce value to the desired type if possible
+  return r.status ? exess_make_nothing(r.status)
+                  : exess_coerce(v, value_type, EXESS_REDUCE_PRECISION);
+}
+
+bool
+serd_get_boolean(const SerdNode* const node)
+{
+  const ExessVariant value = serd_node_get_value_as(node, EXESS_BOOLEAN);
+
+  return (value.datatype == EXESS_BOOLEAN) ? *exess_get_boolean(&value) : false;
+}
+
+double
+serd_get_double(const SerdNode* const node)
+{
+  const ExessVariant value = serd_node_get_value_as(node, EXESS_DOUBLE);
+
+  return (value.datatype == EXESS_DOUBLE) ? *exess_get_double(&value)
+                                          : (double)NAN;
+}
+
+float
+serd_get_float(const SerdNode* const node)
+{
+  const ExessVariant value = serd_node_get_value_as(node, EXESS_FLOAT);
+
+  return (value.datatype == EXESS_FLOAT) ? *exess_get_float(&value) : NAN;
+}
+
+int64_t
+serd_get_integer(const SerdNode* const node)
+{
+  const ExessVariant value = serd_node_get_value_as(node, EXESS_LONG);
+
+  return (value.datatype == EXESS_LONG) ? *exess_get_long(&value) : 0;
+}
+
 SerdNode*
 serd_node_copy(const SerdNode* node)
 {
@@ -585,7 +647,7 @@ serd_new_decimal(const double d, const SerdNode* const datatype)
 }
 
 SerdNode*
-serd_new_integer(int64_t i, const SerdNode* datatype)
+serd_new_integer(const int64_t i, const SerdNode* datatype)
 {
   const ExessVariant variant = exess_make_long(i);
   const size_t       len     = exess_write_variant(variant, 0, NULL).count;