Add SERD_READ_EXACT_BLANKS flag

This allows suppressing the blank node ID clashing mechanism to read blank IDs
exactly as they appear in the input, even if they match the scheme used to
generate blank node IDs internally.

2 files changed, 4 insertions, 3 deletions

diff --git a/include/serd/serd.h b/include/serd/serd.h
index b125bb3d..f3402dd1 100644
--- a/include/serd/serd.h
+++ b/include/serd/serd.h
@@ -304,8 +304,9 @@ typedef struct {
 
 /// Reader options
 typedef enum {
-  SERD_READ_LAX       = 1u << 0u, ///< Tolerate invalid input where possible
-  SERD_READ_VARIABLES = 1u << 1u  ///< Support variable nodes
+  SERD_READ_LAX          = 1u << 0u, ///< Tolerate invalid input where possible
+  SERD_READ_VARIABLES    = 1u << 1u, ///< Support variable nodes
+  SERD_READ_EXACT_BLANKS = 1u << 2u, ///< Allow clashes with generated blanks
 } SerdReaderFlag;
 
 /// Bitwise OR of SerdReaderFlag values
diff --git a/src/n3.c b/src/n3.c
index 1ae98a56..6036bc7f 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -1043,7 +1043,7 @@ read_BLANK_NODE_LABEL(SerdReader* reader, SerdNode** dest, bool* ate_dot)
     *ate_dot = true;
   }
 
-  if (fancy_syntax(reader)) {
+  if (fancy_syntax(reader) && !(reader->flags & SERD_READ_EXACT_BLANKS)) {
     if (is_digit(buf[reader->bprefix_len + 1])) {
       if ((buf[reader->bprefix_len]) == 'b') {
         buf[reader->bprefix_len] = 'B'; // Prevent clash