TypeHelper.swift at master ⋅ ReSwift/ReSwift

//
//  TypeHelper.swift
//  ReSwift
//
//  Created by Benjamin Encz on 11/27/15.
//  Copyright © 2015 ReSwift Community. All rights reserved.
//

/**
 Method is only used internally in ReSwift to cast the generic `StateType` to a specific
 type expected by reducers / store subscribers.

 - parameter action: An action that will be passed to `handleAction`.
 - parameter state: A generic state type that will be casted to `SpecificStateType`.
 - parameter function: The `handleAction` method.
 - returns: A `StateType` from `handleAction` or the original `StateType` if it cannot be
            casted to `SpecificStateType`.
 */
@discardableResult
func withSpecificTypes<SpecificStateType, Action>(
        _ action: Action,
        state genericStateType: Any?,
        function: (_ action: Action, _ state: SpecificStateType?) -> SpecificStateType
    ) -> Any {
        guard let genericStateType = genericStateType else {
            return function(action, nil) as Any
        }

        guard let specificStateType = genericStateType as? SpecificStateType else {
            return genericStateType
        }

        return function(action, specificStateType) as Any
}

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1		//
2		// TypeHelper.swift
3		// ReSwift
4		//
5		// Created by Benjamin Encz on 11/27/15.
6		// Copyright © 2015 ReSwift Community. All rights reserved.
7		//
8
9		/**
10		Method is only used internally in ReSwift to cast the generic `StateType` to a specific
11		type expected by reducers / store subscribers.
12
13		- parameter action: An action that will be passed to `handleAction`.
14		- parameter state: A generic state type that will be casted to `SpecificStateType`.
15		- parameter function: The `handleAction` method.
16		- returns: A `StateType` from `handleAction` or the original `StateType` if it cannot be
17		casted to `SpecificStateType`.
18		*/
19		@discardableResult
20		func withSpecificTypes<SpecificStateType, Action>(
21		_ action: Action,
22		state genericStateType: Any?,
23		function: (_ action: Action, _ state: SpecificStateType?) -> SpecificStateType
24	5	) -> Any {
25	5	guard let genericStateType = genericStateType else {
26	5	return function(action, nil) as Any
27		}
28
29	5	guard let specificStateType = genericStateType as? SpecificStateType else {
30	5	return genericStateType
31		}
32
33	5	return function(action, specificStateType) as Any
34		}