Generate the core register interface

src/Device.tt

@@ -12,6 +12,11 @@
 var publicRegisters = DeviceMetadata.Registers.Where(register => register.Value.Visibility == RegisterVisibility.Public).ToList();
 var deviceRegisters = DeviceMetadata.Registers;
 var deviceName = DeviceMetadata.Device;
+var isApplicationDevice = DeviceMetadata.IsApplicationDevice;
+#>
+<#
+if (isApplicationDevice)
+{
 #>
 using Bonsai;
 using Bonsai.Harp;
@@ -21,9 +26,25 @@ using System.ComponentModel;
 using System.Linq;
 using System.Reactive.Linq;
 using System.Xml.Serialization;
+<#
+}
+else
+{
+#>
+using Bonsai.Harp;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+<#
+} // isApplicationDevice
+#>
 
 namespace <#= Namespace #>
 {
+<#
+if (isApplicationDevice)
+{
+#>
     /// <summary>
     /// Generates events and processes commands for the <#= deviceName #> device connected
     /// at the specified serial port.
@@ -53,6 +74,19 @@ namespace <#= Namespace #>
             (Bonsai.Harp.Device.RegisterMap.ToDictionary(entry => entry.Key, entry => entry.Value))
         {
 <#
+}
+else
+{
+#>
+    public partial class Device
+    {
+        /// <summary>
+        /// Gets a read-only mapping from address to register type.
+        /// </summary>
+        public static IReadOnlyDictionary<int, Type> RegisterMap { get; } = new Dictionary<int, Type>
+        {
+<#
+} // isApplicationDevice
 int registerIndex = 0;
 foreach (var register in deviceRegisters)
 {
@@ -62,6 +96,10 @@ foreach (var register in deviceRegisters)
 }
 #>
         };
+<#
+if (isApplicationDevice)
+{
+#>
 
         /// <summary>
         /// Gets the contents of the metadata file describing the <see cref="<#= deviceName #>"/>
@@ -76,7 +114,14 @@ foreach (var register in deviceRegisters)
             using var streamReader = new System.IO.StreamReader(metadataStream);
             return streamReader.ReadToEnd();
         }
+<#
+} // isApplicationDevice
+#>
     }
+<#
+if (isApplicationDevice)
+{
+#>
 
     /// <summary>
     /// Represents an operator that returns the contents of the metadata file
@@ -388,6 +433,8 @@ foreach (var register in publicRegisters)
         string INamedElement.Name => $"{nameof(<#= deviceName #>)}.{GetElementDisplayName(Register)}";
     }
 <#
+} // deviceRegisters.Count > 0
+} // isApplicationDevice
 foreach (var registerMetadata in deviceRegisters)
 {
     var register = registerMetadata.Value;
@@ -647,6 +694,8 @@ if (isPrivate)
     }
 <#
 }
+if (isApplicationDevice && deviceRegisters.Count > 0)
+{
 #>
 
     /// <summary>
@@ -691,6 +740,7 @@ foreach (var register in publicRegisters)
         string INamedElement.Name => $"{nameof(<#= deviceName #>)}.{GetElementDisplayName(Payload)}";
     }
 <#
+} // isApplicationDevice && deviceRegisters.Count > 0
 foreach (var registerMetadata in publicRegisters)
 {
     var register = registerMetadata.Value;
@@ -824,9 +874,6 @@ foreach (var registerMetadata in publicRegisters)
 }
 #>
 <#
-} // deviceRegisters.Count > 0
-#>
-<#
 var payloadTypes = new HashSet<string>();
 foreach (var registerMetadata in deviceRegisters)
 {

src/Interface.cs

@@ -54,6 +54,12 @@ public class DeviceMetadata
     /// Specifies the collection of group masks available to be used with the different registers.
     /// </summary>
     public Dictionary<string, GroupMaskInfo> GroupMasks = [];
+
+    /// <summary>
+    /// Gets a value indicating whether the metadata describes an application device.
+    /// </summary>
+    [YamlIgnore]
+    public bool IsApplicationDevice => !string.IsNullOrEmpty(Device);
 }
 
 /// <summary>

src/InterfaceGenerator.cs

@@ -12,6 +12,7 @@ public sealed class InterfaceGenerator
     readonly Device _deviceTemplate = new();
     readonly AsyncDevice _asyncDeviceTemplate = new();
     readonly CompilerErrorCollection errors = [];
+    readonly bool isApplicationDevice;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="InterfaceGenerator"/> class with the
@@ -28,6 +29,7 @@ public InterfaceGenerator(DeviceMetadata deviceMetadata, string ns)
         };
         _deviceTemplate.Initialize(InterfaceImplementation.DeviceFileName, errors, session);
         _asyncDeviceTemplate.Initialize(InterfaceImplementation.AsyncDeviceFileName, errors, session);
+        isApplicationDevice = deviceMetadata.IsApplicationDevice;
     }
 
     /// <summary>
@@ -41,7 +43,7 @@ public InterfaceGenerator(DeviceMetadata deviceMetadata, string ns)
     /// <returns>The generated device interface implementation.</returns>
     public InterfaceImplementation GenerateImplementation() =>
         new(Device: _deviceTemplate.TransformText(),
-            AsyncDevice: _asyncDeviceTemplate.TransformText());
+            AsyncDevice: isApplicationDevice ? _asyncDeviceTemplate.TransformText() : string.Empty);
 }
 
 /// <summary>
@@ -72,7 +74,8 @@ public record struct InterfaceImplementation(string Device, string AsyncDevice)
     public readonly IEnumerator<KeyValuePair<string, string>> GetEnumerator()
     {
         yield return new(DeviceFileName, Device);
-        yield return new(AsyncDeviceFileName, AsyncDevice);
+        if (!string.IsNullOrEmpty(AsyncDevice))
+            yield return new(AsyncDeviceFileName, AsyncDevice);
     }
 
     readonly IEnumerator IEnumerable.GetEnumerator()

src/Python.cs

@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using Bonsai.Harp;
 
 namespace Harp.Generators;
@@ -77,7 +76,6 @@ internal sealed class PythonRegister
 
 internal static partial class TemplateHelper
 {
-    const int CoreRegisterAddressLimit = 32;
     const string CoreMetadataResourceName = "Harp.Generators.core.yml";
 
     static readonly Dictionary<string, string> PrimitiveNumpyTypes = new()
@@ -215,7 +213,7 @@ public static PythonModule BuildPythonModule(DeviceMetadata deviceMetadata)
             BuildPythonRegister(module, registerMetadata.Key, registerMetadata.Value, deviceMetadata);
 
         module.ProtocolImports.Add("RegisterBase");
-        module.IsApplicationDevice = deviceMetadata.Registers.Values.All(register => register.Address >= CoreRegisterAddressLimit);
+        module.IsApplicationDevice = deviceMetadata.IsApplicationDevice;
         return module;
     }
 

src/core.yml

@@ -1,6 +1,5 @@
 # yaml-language-server: $schema=https://harp-tech.org/draft-02/schema/registers.json
 description: The core register set every Harp device carries, and its address space.
-device: Tests
 registers:
   WhoAmI:
     address: 0