Handle LDKStr traits and nested array return types

Author: arik-so

bindings/LDK/Bindings.swift

@@ -4539,10 +4539,10 @@ withUnsafePointer(to: htlc.cOpaqueStruct!) { (htlcPointer: UnsafePointer<LDKHTLC
 		return UnsafePointer<UInt8>(dataMutablePointer)
 	}
 
-	public class func new_LDKStr(string: String) -> LDKStr {
-		let nativeType = Self.string_to_unsafe_uint8_pointer(string: string)
-		return LDKStr(chars: nativeType, len: UInt(string.count), chars_is_owned: false)
-	}
+	public class func new_LDKStr(string: String, chars_is_owned: Bool = false) -> LDKStr {
+        let nativeType = Self.string_to_unsafe_uint8_pointer(string: string)
+        return LDKStr(chars: nativeType, len: UInt(string.count), chars_is_owned: chars_is_owned)
+    }
 
     public class func createInvoiceFromChannelManager(channelManager: ChannelManager, keysManager: KeysInterface, network: LDKCurrency, amountMsat: UInt64?, description: String) -> Result_InvoiceSignOrCreationErrorZ {
 		let nativeKeysManager = keysManager.cOpaqueStruct!

src/conversion_helper.py

@@ -372,28 +372,37 @@ def prepare_return_value(cls, return_type, is_clone_method=False, is_trait_insta
 		if rust_return_type is not None and rust_return_type.startswith('LDK') and return_type_string.startswith('['):
 			return_prefix = f'Bindings.{rust_return_type}_to_array(nativeType: '
 			return_suffix = ')'
-			map_suffix = ''
+			individual_map_suffix = ''
 			if (rust_return_type.startswith('LDKCVec_') or rust_return_type == 'LDKTransaction') and is_raw_property_getter:
 				return_suffix = ', deallocate: false)'
-				map_suffix = '.dangle()'
+				individual_map_suffix = '.dangle()'
 
 			if TypeParsingRegeces.WRAPPER_TYPE_ARRAY_BRACKET_REGEX.search(return_type_string) and not is_trait_callback:
 				# replace the last [ with [LDK (in case
 				constructor_type = return_type_string.lstrip('[').rstrip(']')
 				# native_return_type_string = TypeParsingRegeces.WRAPPER_TYPE_ARRAY_BRACKET_REGEX.sub('[LDK', return_type_string)
 				# native_return_type_string = return_type_string.replace('LDKResult_', 'LDKCResult_').replace('LDKTuple_', 'LDKCTuple_').replace('LDKVec_', 'LDKCVec_')
 
+				wrapper_depth = int((len(return_type_string) - len(constructor_type)) / 2)
+
 				if constructor_type == 'Txid':
 					return_suffix += f'''
 					.map {{ (bytes) in
 						   Bindings.LDKThirtyTwoBytes_to_array(nativeType: bytes)
 					}}
 				'''
 				else:
+
+					map_prefix = f'''.map {{ (cOpaqueStruct) in 
+						cOpaqueStruct''' * (wrapper_depth-1)
+					
+					map_suffix = '}' * wrapper_depth
+					
 					return_suffix += f'''
+						{map_prefix}
 						.map {{ (cOpaqueStruct) in
-							{constructor_type}(pointer: cOpaqueStruct){map_suffix}
-						}}
+							{constructor_type}(pointer: cOpaqueStruct){individual_map_suffix}
+						{map_suffix}
 					'''
 
 

src/generators/trait_generator.py

@@ -176,6 +176,12 @@ def generate_trait(self, struct_name, struct_details):
 				swift_default_return = 'return 0'
 			if swift_return_type.startswith('Bool'):
 				swift_default_return = 'return false'
+			if swift_raw_return_type == 'String' and swift_return_type == 'String':
+				return_conversion_prefix = f'Bindings.new_LDKStr(string: '
+				return_conversion_suffix = ', chars_is_owned: true)'
+				swift_raw_return_type = 'LDKStr'
+				swift_default_return = ''
+				is_default_return_error = True
 			if swift_return_type.startswith('UnsafeMutableRawPointer'):
 				swift_raw_return_type += '?'
 				swift_default_return = 'return UnsafeMutableRawPointer(bitPattern: 0)!'

templates/BindingsTemplate.swift

@@ -346,10 +346,10 @@ public class Bindings {
 		return UnsafePointer<UInt8>(dataMutablePointer)
 	}
 
-	public class func new_LDKStr(string: String) -> LDKStr {
-		let nativeType = Self.string_to_unsafe_uint8_pointer(string: string)
-		return LDKStr(chars: nativeType, len: UInt(string.count), chars_is_owned: false)
-	}
+	public class func new_LDKStr(string: String, chars_is_owned: Bool = false) -> LDKStr {
+        let nativeType = Self.string_to_unsafe_uint8_pointer(string: string)
+        return LDKStr(chars: nativeType, len: UInt(string.count), chars_is_owned: chars_is_owned)
+    }
 
     public class func createInvoiceFromChannelManager(channelManager: ChannelManager, keysManager: KeysInterface, network: LDKCurrency, amountMsat: UInt64?, description: String) -> Result_InvoiceSignOrCreationErrorZ {
 		let nativeKeysManager = keysManager.cOpaqueStruct!