Files
gp4/Sources/P4/Support.swift
T
Will Hawkins 995abcc470 Add License Information
Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
2026-01-23 23:51:49 -05:00

73 lines
2.1 KiB
Swift

// p4rse, Copyright 2026, Will Hawkins
//
// This file is part of p4rse.
// This file is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
public struct Error: Equatable {
public private(set) var msg: String
public init(withMessage msg: String) {
self.msg = msg
}
}
public struct Nothing: CustomStringConvertible {
public var description: String {
return "Nothing"
}
public init() {}
}
public enum Result<T>: Equatable, CustomStringConvertible {
case Ok(T)
case Error(Error)
public static func == (lhs: Result, rhs: Result) -> Bool {
switch (lhs, rhs) {
case (Ok, Ok):
return true
case (Error(let le), Error(let re)):
return le.msg == re.msg
default:
return false
}
}
public func error() -> Error? {
if case Result.Error(let e) = self {
return e
}
return nil
}
public var description: String {
switch self {
case Result.Error(let e):
return e.msg
case Result.Ok(let o):
return "\(o)"
}
}
}
@freestanding(expression) public macro RequireOkResult<T>(_: Result<T>) -> Bool =
#externalMacro(module: "P4Macros", type: "RequireResult")
@freestanding(expression) public macro RequireErrorResult<T>(_: Error, _: Result<T>) -> Bool =
#externalMacro(module: "P4Macros", type: "RequireErrorResult")
@freestanding(expression) public macro UseOkResult<T>(_: Result<T>) -> T =
#externalMacro(module: "P4Macros", type: "UseOkResult")