* Update trees API to use NodeId (#145)

* Add NULL_NODE_ID
* Add NULL_NODE_ID to prelude.rs

Author: molpopgen

src/_macros.rs

@@ -234,7 +234,7 @@ macro_rules! table_row_access {
 macro_rules! iterator_for_nodeiterator {
     ($ty: ty) => {
         impl Iterator for $ty {
-            type Item = $crate::tsk_id_t;
+            type Item = $crate::NodeId;
             fn next(&mut self) -> Option<Self::Item> {
                 self.next_node();
                 self.current_node()
@@ -246,7 +246,10 @@ macro_rules! iterator_for_nodeiterator {
 macro_rules! tree_array_slice {
     ($self: ident, $array: ident, $len: expr) => {
         unsafe {
-            std::slice::from_raw_parts((*$self.as_ptr()).$array as *const tsk_id_t, $len as usize)
+            std::slice::from_raw_parts(
+                (*$self.as_ptr()).$array as *const $crate::NodeId,
+                $len as usize,
+            )
         }
     };
 }

src/lib.rs

@@ -210,6 +210,9 @@ impl_id_traits!(EdgeId);
 /// "Null" identifier value.
 pub const TSK_NULL: tsk_id_t = -1;
 
+/// "Null" identifier value for [``NodeId``]
+pub const NULL_NODE_ID: NodeId = NodeId(-1);
+
 pub use edge_table::{EdgeTable, EdgeTableRow};
 pub use error::TskitError;
 pub use flags::*;

src/prelude.rs

@@ -6,6 +6,7 @@ pub use crate::tsk_size_t;
 pub use crate::NodeListGenerator;
 pub use crate::TableAccess;
 pub use crate::TskitTypeAccess;
+pub use crate::NULL_NODE_ID;
 pub use crate::TSK_NODE_IS_SAMPLE;
 pub use crate::TSK_NULL;
 pub use streaming_iterator::DoubleEndedStreamingIterator;

src/test_simplification.rs

@@ -39,7 +39,7 @@ mod tests {
         assert!(idmap_option.is_some());
         let idmap = idmap_option.unwrap();
         for &i in samples {
-            assert_ne!(idmap[i as usize], TSK_NULL);
+            assert_ne!(idmap[usize::from(i)], TSK_NULL);
         }
     }
 }