53 lines
2.3 KiB
Swift
53 lines
2.3 KiB
Swift
//
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// DuckDB
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// https://github.com/duckdb/duckdb-swift
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//
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// Copyright © 2018-2024 Stichting DuckDB Foundation
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to
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// deal in the Software without restriction, including without limitation the
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// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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// sell copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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// IN THE SOFTWARE.
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public struct CodingUserInfoKeys {
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/// This key is set on the `userInfo` dictionary of the `Decoder` that is
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/// used when transforming data into a `Decodable`. The value is the ``LogicalType``
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/// of the element being decoded. This can be used to implement dynamic decoding
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/// behavior based on the underlying database type.
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///
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/// For example:
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/// ```swift
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/// struct DynamicDecodable: Decodable {
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/// init(from decoder: Decoder) throws {
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/// guard let logicalType = decoder.userInfo[CodingUserInfoKeys.logicalType] as? LogicalType else {
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/// throw Error.expectedLogicalType
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/// }
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/// switch logicalType.dataType {
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/// case .list:
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/// let unkeyedContainer = try decoder.unkeyedContainer()
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/// ...
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/// case .map, .struct:
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/// let keyedContainer = try decoder.container(keyedBy: AnyCodingKey.self)
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/// ...
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/// }
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/// }
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/// }
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///
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/// let column = result[0].cast(to: DynamicDecodable.self)
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/// ```
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public static let logicalTypeCodingUserInfoKey = CodingUserInfoKey(rawValue: "logicalType")!
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}
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