Add CompactVector usage example

CHANGELOG.md

@@ -51,3 +51,4 @@
 - Split inspection tests so each assertion stands alone.
 - Documented `WaveletMatrix` usage in `README.md`.
 - Moved README usage examples to runnable files in `examples/`.
+- Added `compact_vector` example showing construction and retrieval.

INVENTORY.md

@@ -5,7 +5,6 @@
 
 ## Desired Functionality
 - Provide more usage examples and documentation.
-- Add usage example demonstrating `CompactVector` construction and retrieval.
 - Evaluate additional succinct data structures to include.
 - Investigate alternative dense-select index strategies to replace removed `DArrayIndex`.
 

README.md

@@ -32,7 +32,8 @@ byte region to `Bytes::from_source`.
 
 ## Examples
 
-See the [examples](examples/) directory for runnable usage demos.
+See the [examples](examples/) directory for runnable usage demos, including
+`bit_vector`, `wavelet_matrix`, and `compact_vector`.
 
 ## Licensing
 

examples/compact_vector.rs

@@ -0,0 +1,13 @@
+use jerky::int_vectors::CompactVectorBuilder;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Build a vector storing integers within 3 bits each.
+    let mut builder = CompactVectorBuilder::new(3)?;
+    builder.extend([7, 2, 5])?;
+    let cv = builder.freeze();
+
+    assert_eq!(cv.len(), 3);
+    assert_eq!(cv.get_int(0), Some(7));
+    assert_eq!(cv.get_int(2), Some(5));
+    Ok(())
+}