mirror of
https://github.com/apple/swift-argument-parser.git
synced 2026-06-06 20:18:23 +00:00
Nate Cook
a76f59f446
When deriving input from a non-interactive source, send the prompts to a null output stream rather than to stdout.
54 lines
1.4 KiB
Swift
54 lines
1.4 KiB
Swift
//===----------------------------------------------------------*- swift -*-===//
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//
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// This source file is part of the Swift Argument Parser open source project
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//
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// Copyright (c) 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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//
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//===----------------------------------------------------------------------===//
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/// Ask the user to confirm the prompt.
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///
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/// ```swift
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/// guard
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/// check("Are you sure you want to delete all?")
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/// else { return }
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/// print("---DELETE---")
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/// ```
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///
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/// The above code will generate the following dialog:
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///
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/// ```
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/// Are you sure you want to delete all?
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/// ? Please enter [y]es or [n]o: y
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/// ---DELETE---
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/// ```
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/// - Parameters:
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/// - prompt: The message to display.
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/// - getInput: Get input from the user's typing or other ways.
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/// - Returns: The user decision.
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internal func check<Target: TextOutputStream>(
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_ prompt: String,
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to output: inout Target,
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getInput: () -> String? = { readLine() }
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) -> Bool {
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print(prompt, to: &output)
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while true {
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print("? Please enter [y]es or [n]o: ", terminator: "", to: &output)
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let input = getInput()?
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.trimmingCharacters(in: .whitespaces)
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.lowercased()
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?? ""
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switch input {
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case "y", "yes": return true
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case "n", "no": return false
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default: continue
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}
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}
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}
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