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hummingbird-docc/Sources/HummingbirdDocC/Internal/Extensions/String+Helpers.swift
T
javier 1382f33ae6 Added (first version of) sample Hummingbird app. (#4)
This PR contains the work done to:
* Implemented a basic `Hummingbird` application in which to integrate the `HummingbirdDocC` library.
* Added the *ArgumentParser* package dependency to the `Package.swift` file;
* Added a new *sample* target to the `Package.swift` file;
* Added library and documentation tasks to the `Makefile` file.

Reviewed-on: #4
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>
2025-09-30 15:38:12 +00:00

47 lines
1.3 KiB
Swift

// ===----------------------------------------------------------------------===
//
// This source file is part of the Hummingbird DocC Middleware open source project
//
// Copyright (c) 2025 Röck+Cöde VoF. and the Hummingbird DocC Middleware project authors
// Licensed under the EUPL 1.2 or later.
//
// See LICENSE for license information
// See CONTRIBUTORS for the list of Hummingbird DocC Middleware project authors
//
// ===----------------------------------------------------------------------===
import RegexBuilder
extension String {
/// Subtracts a prefix from a string.
/// - Parameters:
/// - prefix: A prefix to remove from a string.
/// - Returns: A new string with a prefix removed, if any.
func subtract(
_ prefix: String
) -> String? {
let reference = Reference(String.self)
let pattern = Regex {
prefix
Optionally {
Capture(as: reference) {
OneOrMore(.anyNonNewline)
} transform: { output in
String(output)
}
}
}
guard let matches = self.prefixMatch(of: pattern) else {
return nil
}
guard let subtracted = matches.output.1 else {
return .empty
}
return subtracted
}
}