Add GeoArrow types.

.github/workflows/pull_request.yml

@@ -28,7 +28,7 @@ jobs:
     uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
     with:
       macos_exclude_xcode_versions: "[{\"xcode_version\": \"16.0\"}, {\"xcode_version\": \"16.1\"}, {\"xcode_version\": \"16.2\"}, {\"xcode_version\": \"16.3\"}]"
-      linux_exclude_swift_versions: "[{\"swift_version\": \"5.9\"}, {\"swift_version\": \"5.10\"}, {\"swift_version\": \"6.0\"}, {\"swift_version\": \"6.1\"}, {\"swift_version\": \"nightly-main\"}, {\"swift_version\": \"nightly-6.1\"}]"
+      linux_exclude_swift_versions: "[{\"swift_version\": \"5.9\"}, {\"swift_version\": \"5.10\"}, {\"swift_version\": \"6.0\"}, {\"swift_version\": \"6.1\"}, {\"swift_version\": \"nightly-main\"}, {\"swift_version\": \"nightly-6.1\"}, {\"swift_version\": \"nightly-6.3\"}]"
       windows_exclude_swift_versions: "[{\"swift_version\": \"5.9\"}, {\"swift_version\": \"6.0\"}, {\"swift_version\": \"6.1\"}, {\"swift_version\": \"nightly\"}, {\"swift_version\": \"nightly-6.1\"}]"
       enable_macos_checks: false
       enable_windows_checks: false

Package.swift

@@ -29,7 +29,7 @@ let package = Package(
   dependencies: [
     .package(
       url: "https://github.com/google/flatbuffers.git",
-      exact: "25.2.10"
+      exact: "25.12.19"
     ),
     .package(
       url: "https://github.com/apple/swift-atomics.git",

README.md

@@ -6,9 +6,9 @@ The in-memory contiguous buffers allow constant-time random access to large, str
 
 ## Project status:
 
-IPC serialization / deserialization has been tested against the Arrow integration testing JSON files, using the following strategy:
+IPC deserialization has been tested against the Arrow integration testing JSON files (gold test files), using the following strategy:
 
-1. Read the [Arrow cpp21 generated files](https://github.com/apache/arrow-testing/tree/master/data/arrow-ipc-stream/integration/cpp-21.0.0) into memory.
+1. Read the Arrow integration test files into memory.
 2. Encode the results to Codable & Equatable structs that can read and write the [test data format.](https://arrow.apache.org/docs/format/Integration.html#json-test-data-format).
 3. Read the test JSON into the same Codable & Equatable struct and compare with the deserialized results,using Swift equality. This 
 
@@ -125,7 +125,7 @@ typealias ArrowArrayUtf8 = ArrowArrayVariable<
   FixedWidthBufferIPC<Int32>,
   VariableLengthBufferIPC<String>
 >
-``
+```
 
 ## Relationship to Arrow-Swift
 

Scripts/flatc/Dockerfile

@@ -10,7 +10,7 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/*
 
 # Build FlatBuffers from source (ARM-compatible)
-ENV FLATBUFFERS_VERSION=25.9.23
+ENV FLATBUFFERS_VERSION=25.12.19
 RUN git clone --depth 1 --branch v${FLATBUFFERS_VERSION} https://github.com/google/flatbuffers.git && \
     cd flatbuffers && \
     cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release . && \

Scripts/flatc/compile-flatbuffers.sh

@@ -1,2 +1,2 @@
 #!/bin/bash
-container run -v "$(pwd)":/src flatc File.fbs
+container run -v "$(pwd)":/src flatc File.fbs Message.fbs Schema.fbs SparseTensor.fbs Tensor.fbs

Scripts/readArrowIPC.py

@@ -1,19 +1,20 @@
 # Useful for debugging IPC writing issues.
-import pyarrow as pa
 import sys
 
+import pyarrow as pa
+
 print(f"PyArrow version: {pa.__version__}")
 
 try:
     with open(sys.argv[1], 'rb') as f:
         reader = pa.ipc.open_file(f)
         print(f"Schema: {reader.schema}")
         print(f"Num batches: {reader.num_record_batches}")
-        
+
         for i in range(reader.num_record_batches):
             batch = reader.get_batch(i)
             print(f"Batch {i}: {batch.num_rows} rows, {batch.num_columns} columns")
-        
+
         print("✓ File read successfully")
 except Exception as e:
     print(f"✗ Error: {e}")

Sources/Arrow/Array/Array.swift

@@ -54,7 +54,7 @@ extension ArrowArrayBinaryView: StringArrayProtocol where ItemType == String {}
 /// A type which provides access to arrays of `Data`,  with opaque offset types.
 ///
 /// The underlying array may have fixed or variable-length items.
-protocol BinaryArrayProtocol: AnyArrowArrayProtocol {
+public protocol BinaryArrayProtocol: AnyArrowArrayProtocol {
   subscript(index: Int) -> Data? { get }
 }
 extension ArrowArrayFixedSizeBinary: BinaryArrayProtocol {}

Sources/Arrow/Array/ArrowColumn.swift

@@ -14,7 +14,7 @@
 // limitations under the License.
 
 public class ArrowColumn {
-  let dataHolder: any ChunkedArrayProtocol
+  public let dataHolder: any ChunkedArrayProtocol
   public let field: ArrowField
   public var length: Int { self.dataHolder.length }
   public var nullCount: Int { self.dataHolder.nullCount }

Sources/Arrow/ArrowError.swift

@@ -21,7 +21,7 @@ public struct ArrowError: Error {
     case outOfBounds(index: Int64)
     case arrayHasNoElements
     case unknownError(String)
-    case notImplemented
+    case notImplemented(String)
     case ioError(String)
     case invalid(String)
   }

Sources/Arrow/ArrowType.swift

@@ -645,7 +645,7 @@ extension ArrowType {
   @inlinable
   public var isVariable: Bool {
     switch self {
-    case .binary, .utf8: true
+    case .binary, .utf8, .largeBinary, .largeUtf8: true
     default: false
     }
   }
@@ -963,7 +963,7 @@ extension ArrowType {
       case .list(let field):
         return "+l" + (try field.type.cDataFormatId)
       default:
-        throw .init(.notImplemented)
+        throw .init(.notImplemented("cData not implmented for \(self)."))
       }
     }
   }
@@ -1033,6 +1033,6 @@ extension ArrowType {
     } else if from == "u" {
       return .utf8
     }
-    throw .init(.notImplemented)
+    throw .init(.notImplemented("cData not implmented for \(self)."))
   }
 }

Sources/Arrow/Buffer/BinaryView.swift

@@ -91,7 +91,7 @@
     return view
   }
 
-  /// Create a referenced view (for length > 12) - trivial!
+  /// Create a referenced view (for length > 12) .
   public static func referenced(
     length: Int32,
     prefix: UInt32,
@@ -107,7 +107,6 @@
     view.words[1] = Int32(bitPattern: prefix)
     view.words[2] = bufferIndex
     view.words[3] = offset
-
     return view
   }
 }

Sources/Arrow/Extensions.swift

@@ -0,0 +1,39 @@
+// Copyright 2026 The Columnar Swift Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+extension ArrowField {
+
+  /// Return the GeoArrow extension type if set, else returns nil.
+  public var geoArrowType: GeoArrowType? {
+    metadata["ARROW:extension:name"].flatMap { GeoArrowType(rawValue: $0) }
+  }
+}
+
+/// The GeoArrow types.
+///
+/// Use these in conjunction with a column's `ArrowType` to interpret a geometry column. There are
+/// multiple possible memory layouts for each type.
+public enum GeoArrowType: String {
+  case point = "geoarrow.point"
+  case linestring = "geoarrow.linestring"
+  case polygon = "geoarrow.polygon"
+  case multipoint = "geoarrow.multipoint"
+  case multilinestring = "geoarrow.multilinestring"
+  case multipolygon = "geoarrow.multipolygon"
+  case geometry = "geoarrow.geometry"
+  case geometrycollection = "geoarrow.geometrycollection"
+  case box = "geoarrow.box"
+  case wkb = "geoarrow.wkb"
+  case wkt = "geoarrow.wkt"
+}