refactor: changed the behaviour of turn_into_cstr_c, it returns at le…

…ast ""
aiq · Jun 27, 2024 · e7b9efd · e7b9efd
1 parent bbff6c7
commit e7b9efd
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Showing 4 changed files with 20 additions and 17 deletions.
diff --git a/doc/clingo/io/cRecorder.adoc b/doc/clingo/io/cRecorder.adoc
@@ -616,7 +616,8 @@ char* turn_into_cstr_c( cRecorder rec[static 1] );
 
 Records if necessary a null character, moves the recorder to the beginning and
 returns the recorded memory as C string.
-Returns NULL if the function can not finish the memory with a null character.
+Returns an empty C string if the function can not finish the memory with a
+null character.
 
 .Example
 [source,c]

diff --git a/inc/clingo/io/cRecorder.h b/inc/clingo/io/cRecorder.h
@@ -122,12 +122,9 @@ CLINGO_API cPen recorder_pen_c( cRecorder rec[static 1] );
  mem
 *******************************************************************************/
 
-CLINGO_API
-bool alloc_recorder_mem_c( cRecorder rec[static 1], int64_t size );
-CLINGO_API
-bool realloc_recorder_mem_c( cRecorder rec[static 1], int64_t size );
-CLINGO_API
-void free_recorder_mem_c( cRecorder rec[static 1] );
+CLINGO_API bool alloc_recorder_mem_c( cRecorder rec[static 1], int64_t size );
+CLINGO_API bool realloc_recorder_mem_c( cRecorder rec[static 1], int64_t size );
+CLINGO_API void free_recorder_mem_c( cRecorder rec[static 1] );
 
 CLINGO_API
 inline int64_t recorder_cap_c( cRecorder const rec[static 1] )
@@ -195,6 +192,7 @@ inline void reset_recorder_c( cRecorder rec[static 1] )
 /*******************************************************************************
  recorded
 *******************************************************************************/
+
 CLINGO_API
 inline cBytes recorded_bytes_c( cRecorder const rec[static 1] )
 {

diff --git a/src/clingo/io/cRecorder.c b/src/clingo/io/cRecorder.c
@@ -275,16 +275,20 @@ void println_recorded_c( cRecorder rec[static 1] )
    putchar( '\n' );
 }
 
-char* turn_into_cstr_c( cRecorder rec[static 1] )
+static inline bool finish_cstr( cRecorder rec[static 1] )
 {
-   if ( recorder_cap_c( rec ) == 0 ) return NULL;
+   cChars recorded = recorded_chars_c( rec );
+   if ( not is_empty_c_( recorded ) and
+        last_c_( recorded ) == '\0' )
+      return true;
 
-   if ( not record_char_c( rec, '\0' ) )
-   {
-      char const* cstr = rec->mem;
-      --cstr;
-      if ( *cstr != '\0' ) return NULL;
-   }
+   return record_char_c( rec, '\0' );
+}
+
+char* turn_into_cstr_c( cRecorder rec[static 1] )
+{
+   if ( not finish_cstr( rec ) )
+      return "";
 
    reset_recorder_c( rec );
    return rec->mem;

diff --git a/test/clingo/io/cRecorder/turn_into_cstr.c b/test/clingo/io/cRecorder/turn_into_cstr.c
@@ -10,7 +10,7 @@ int main( void )
 
    rec = &null_recorder_c_();
    cstr = turn_into_cstr_c( rec );
-   expect_at_c_( cstr == NULL );
+   expect_eq_c_( strcmp( cstr, "" ) );
 
    rec = &recorder_c_( 4 );
    cstr = turn_into_cstr_c( rec );
@@ -30,7 +30,7 @@ int main( void )
 
    record_chars_c_( rec, "abcd" );
    cstr = turn_into_cstr_c( rec );
-   expect_at_c_( cstr == NULL );
+   expect_eq_c_( strcmp( cstr, "" ) );
 
    return finish_tap_c_();
 }