Expose .fail as the opposite of .ok

src/bin/run-emitter-test-suite.rs

@@ -47,7 +47,7 @@ pub(crate) unsafe fn unsafe_main(
 ) -> Result<(), Box<dyn Error>> {
     let mut emitter = MaybeUninit::<yaml_emitter_t>::uninit();
     let emitter = emitter.as_mut_ptr();
-    if !yaml_emitter_initialize(emitter).ok {
+    if yaml_emitter_initialize(emitter).fail {
         return Err("Could not initalize the emitter object".into());
     }
 
@@ -133,10 +133,10 @@ pub(crate) unsafe fn unsafe_main(
             break Err(format!("Unknown event: '{}'", CStr::from_ptr(line)).into());
         };
 
-        if !result.ok {
+        if result.fail {
             break Err("Memory error: Not enough memory for creating an event".into());
         }
-        if !yaml_emitter_emit(emitter, event).ok {
+        if yaml_emitter_emit(emitter, event).fail {
             break Err(match (*emitter).error {
                 YAML_MEMORY_ERROR => "Memory error: Not enough memory for emitting".into(),
                 YAML_WRITER_ERROR => {

src/bin/run-parser-test-suite.rs

@@ -40,7 +40,7 @@ pub(crate) unsafe fn unsafe_main(
 ) -> Result<(), Box<dyn Error>> {
     let mut parser = MaybeUninit::<yaml_parser_t>::uninit();
     let parser = parser.as_mut_ptr();
-    if !yaml_parser_initialize(parser).ok {
+    if yaml_parser_initialize(parser).fail {
         return Err("Could not initialize the parser object".into());
     }
 
@@ -66,7 +66,7 @@ pub(crate) unsafe fn unsafe_main(
     let mut event = MaybeUninit::<yaml_event_t>::uninit();
     let event = event.as_mut_ptr();
     loop {
-        if !yaml_parser_parse(parser, event).ok {
+        if yaml_parser_parse(parser, event).fail {
             let mut error = format!("Parse error: {}", CStr::from_ptr((*parser).problem));
             if (*parser).problem_mark.line != 0 || (*parser).problem_mark.column != 0 {
                 let _ = write!(

src/success.rs

@@ -1,3 +1,5 @@
+use core::ops::Deref;
+
 pub const OK: Success = Success { ok: true };
 pub const FAIL: Success = Success { ok: false };
 
@@ -6,6 +8,22 @@ pub struct Success {
     pub ok: bool,
 }
 
+pub struct Failure {
+    pub fail: bool,
+}
+
+impl Deref for Success {
+    type Target = Failure;
+
+    fn deref(&self) -> &Self::Target {
+        if self.ok {
+            &Failure { fail: false }
+        } else {
+            &Failure { fail: true }
+        }
+    }
+}
+
 pub struct Zero;
 
 impl PartialEq<Zero> for Success {