need table-specific columns?

Author: molpopgen

src/lib.rs

@@ -83,7 +83,6 @@
 pub use sys::bindings;
 
 mod _macros; // Starts w/_ to be sorted at front by rustfmt!
-mod table_column;
 mod edge_differences;
 mod edge_table;
 pub mod error;
@@ -98,15 +97,14 @@ pub mod prelude;
 mod site_table;
 mod sys;
 mod table_collection;
+mod table_column;
 mod table_iterator;
 mod traits;
 mod trees;
 pub mod types;
 mod util;
 
-
 pub use edge_differences::*;
-pub use table_column::{TableColumn, MutableTableColumn};
 pub use edge_table::{EdgeTable, EdgeTableRow};
 pub use error::TskitError;
 pub use individual_table::{IndividualTable, IndividualTableRow};
@@ -119,6 +117,7 @@ pub use site_table::{SiteTable, SiteTableRow};
 pub use sys::flags::*;
 pub use sys::NodeTraversalOrder;
 pub use table_collection::TableCollection;
+pub use table_column::{MutableTableColumn, NodeTableColumn, TableColumn};
 pub use traits::IndividualLocation;
 pub use traits::IndividualParents;
 pub use trees::{Tree, TreeSequence};

src/node_table.rs

@@ -807,8 +807,8 @@ impl NodeTable {
         /// Get the population column as a slice
         => population, population_slice_raw, crate::sys::bindings::tsk_id_t);
 
-    pub fn individual_column(&self) -> crate::TableColumn<IndividualId> {
-        crate::table_column::new_table_column(self.individual_slice())
+    pub fn individual_column(&self) -> crate::table_column::NodeTableColumn<IndividualId> {
+        crate::table_column::NodeTableColumn::new(self.individual_slice())
     }
 
     pub fn population_column(&self) -> crate::TableColumn<PopulationId> {

src/table_column.rs

@@ -31,6 +31,47 @@ impl<T> MutableTableColumn<'_, T> {
     }
 }
 
+macro_rules! make_table_column {
+    ($name: ident, $index: ident) => {
+        /// Immutable view of a column
+        pub struct $name<'table, T>(&'table [T]);
+
+        impl<'table, T> $name<'table, T> {
+            pub(crate) fn new(column: &'table [T]) -> $name<'table, T> {
+                Self(column)
+            }
+
+            /// View the underlying slice
+            pub fn as_slice(&self) -> &[T] {
+                self.0
+            }
+        }
+
+        impl<T> std::ops::Index<usize> for $name<'_, T> {
+            type Output = T;
+            fn index(&self, index: usize) -> &Self::Output {
+                &self.0[index]
+            }
+        }
+
+        impl<T> std::ops::Index<crate::$index> for $name<'_, T> {
+            type Output = T;
+            fn index(&self, index: crate::$index) -> &Self::Output {
+                &self.0[usize::try_from(index).unwrap()]
+            }
+        }
+
+        impl<T> std::ops::Index<crate::SizeType> for $name<'_, T> {
+            type Output = T;
+            fn index(&self, index: crate::SizeType) -> &Self::Output {
+                &self.0[usize::try_from(index).unwrap()]
+            }
+        }
+    };
+}
+
+make_table_column!(NodeTableColumn, NodeId);
+
 // NOT part of tskit's public API
 pub fn new_table_column<T>(data: &[T]) -> TableColumn<'_, T> {
     TableColumn(data)