make rust example nicer

Author: molpopgen

examples/json_metadata.rs

@@ -13,45 +13,39 @@ struct IndividualMetadata {
 }
 
 fn main() {
-    let ts = make_treeseq();
+    let ts = make_treeseq().unwrap();
     ts.dump("with_json_metadata.trees", 0).unwrap();
 }
 
-fn make_tables() -> tskit::TableCollection {
-    let mut tables = tskit::TableCollection::new(100.0).unwrap();
-    let pop0 = tables.add_population().unwrap();
-    let ind0 = tables
-        .add_individual_with_metadata(
-            0,
-            None,
-            None,
-            &IndividualMetadata {
-                name: "Jerome".to_string(),
-                phenotypes: vec![0, 1, 2, 0],
-            },
-        )
-        .unwrap();
-    let node0 = tables
-        .add_node(tskit::NodeFlags::new_sample(), 0.0, pop0, ind0)
-        .unwrap();
-    let site0 = tables.add_site(50.0, Some("A".as_bytes())).unwrap();
-    let _ = tables
-        .add_mutation_with_metadata(
-            site0,
-            node0,
-            tskit::MutationId::NULL,
-            1.0,
-            Some("G".as_bytes()),
-            &MutationMetadata {
-                effect_size: -1e-3,
-                dominance: 0.1,
-            },
-        )
-        .unwrap();
-    tables.build_index().unwrap();
-    tables
+fn make_tables() -> anyhow::Result<tskit::TableCollection> {
+    let mut tables = tskit::TableCollection::new(100.0)?;
+    let pop0 = tables.add_population()?;
+    let ind0 = tables.add_individual_with_metadata(
+        0,
+        None,
+        None,
+        &IndividualMetadata {
+            name: "Jerome".to_string(),
+            phenotypes: vec![0, 1, 2, 0],
+        },
+    )?;
+    let node0 = tables.add_node(tskit::NodeFlags::new_sample(), 0.0, pop0, ind0)?;
+    let site0 = tables.add_site(50.0, Some("A".as_bytes()))?;
+    let _ = tables.add_mutation_with_metadata(
+        site0,
+        node0,
+        tskit::MutationId::NULL,
+        1.0,
+        Some("G".as_bytes()),
+        &MutationMetadata {
+            effect_size: -1e-3,
+            dominance: 0.1,
+        },
+    )?;
+    tables.build_index()?;
+    Ok(tables)
 }
 
-fn make_treeseq() -> tskit::TreeSequence {
-    make_tables().tree_sequence(0).unwrap()
+fn make_treeseq() -> anyhow::Result<tskit::TreeSequence> {
+    Ok(make_tables()?.tree_sequence(0)?)
 }