Files
swift-mirror/stdlib/private/OSLog/OSLogStringAlignment.swift
Ravi Kandhadai 7c9ddca1d4 [os log][stdlib/private] Enable precision and alignment values to be dynamic.
The format specifier constructed by the os log implementation uses '*' for
width and precision, and passes those values to the os_log ABIs as additional
arguments of the message. (The precision/alignment arguments have the
type: count).

Update tests to handle this change.
2020-02-25 15:11:48 -08:00

90 lines
2.9 KiB
Swift

//===----------------- OSLogStringAlignment.swift -------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
// This file defines types and functions for specifying alignment of the
// interpolations passed to the os log APIs.
@frozen
public enum OSLogCollectionBound {
case start
case end
}
@frozen
public struct OSLogStringAlignment {
/// Minimum number of characters to be displayed. If the value to be printed
/// is shorter than this number, the result is padded with spaces. The value
/// is not truncated even if the result is larger.This value need not be a
/// compile-time constant, and is therefore an autoclosure.
public var minimumColumnWidth: (() -> Int)?
/// This captures right/left alignment.
public var anchor: OSLogCollectionBound
/// - Parameters:
/// - minimumColumnWidth: Minimum number of characters to be displayed. If the value to be
/// printed is shorter than this number, the result is padded with spaces. The value is not truncated
/// even if the result is larger.
/// - anchor: Use `.end` for right alignment and `.start` for left.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
internal init(
minimumColumnWidth: (() -> Int)? = nil,
anchor: OSLogCollectionBound = .end
) {
self.minimumColumnWidth = minimumColumnWidth
self.anchor = anchor
}
/// Right alignment formatter.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
public static var right: OSLogStringAlignment {
OSLogStringAlignment(anchor: .end)
}
/// Left alignment formatter.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
public static var left: OSLogStringAlignment {
OSLogStringAlignment(anchor: .start)
}
/// Use default alignment, which is right alignment.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
public static var none: OSLogStringAlignment { .right }
/// Right align and display at least`columns` characters.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
public static func right(
columns: @escaping @autoclosure () -> Int
) -> OSLogStringAlignment {
OSLogStringAlignment(minimumColumnWidth: columns, anchor: .end)
}
/// Left align and display at least`columns` characters.
@_semantics("constant_evaluable")
@inlinable
@_optimize(none)
public static func left(
columns: @escaping @autoclosure () -> Int
) -> OSLogStringAlignment {
OSLogStringAlignment(minimumColumnWidth: columns, anchor: .start)
}
}