Files
swift-mirror/stdlib/public/core/FloatingPointParsing.swift.gyb
Karoy Lorentey 6d255658ca Merge pull request #39994 from lorentey/adopt-availability-macros
[stdlib] Adopt availability macros
2021-11-01 14:45:33 -07:00

231 lines
7.5 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2019 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
//
//===----------------------------------------------------------------------===//
import SwiftShims
%{
allFloatBits = [16, 32, 64, 80]
def floatName(bits):
if bits == 16:
return 'Float16'
if bits == 32:
return 'Float'
if bits == 64:
return 'Double'
if bits == 80:
return 'Float80'
cFuncSuffix2 = {16: 'f16', 32: 'f', 64: 'd', 80: 'ld'}
}%
/// Returns `true` if isspace(u) would return nonzero when the current
/// locale is the C locale; otherwise, returns false.
@inlinable // FIXME(sil-serialize-all)
internal func _isspace_clocale(_ u: UTF16.CodeUnit) -> Bool {
return "\t\n\u{b}\u{c}\r ".utf16.contains(u)
}
% for bits in allFloatBits:
% Self = floatName(bits)
% if bits == 80:
#if !(os(Windows) || os(Android)) && (arch(i386) || arch(x86_64))
% elif bits == 16:
#if !((os(macOS) || targetEnvironment(macCatalyst)) && arch(x86_64))
% end
%if bits == 16:
@available(SwiftStdlib 5.3, *)
%end
extension ${Self}: LosslessStringConvertible {
/// Creates a new instance from the given string.
///
/// The string passed as `text` can represent a real number in decimal or
/// hexadecimal format or can be in a special format representing infinity
/// or NaN ("not a number"). If `text` is not in a recognized format,
/// the optional initializer will fail and return `nil`.
///
/// The `text` string consists of an optional
/// plus or minus sign character (`+` or `-`)
/// followed by one of the following:
///
/// - A *decimal string* contains a significand consisting of one
/// or more decimal digits that may include a decimal point:
///
/// let c = ${Self}("-1.0")
/// // c == -1.0
///
/// let d = ${Self}("28.375")
/// // d == 28.375
///
/// A decimal string may also include an exponent following the
/// significand, indicating the power of 10 by which the significand should
/// be multiplied. If included, the exponent is separated by a single
/// character, `e` or `E`, and consists of an optional plus or minus sign
/// character and a sequence of decimal digits.
///
/// let e = ${Self}("2837.5e-2")
/// // e == 28.375
///
/// - A *hexadecimal string* contains a significand consisting of
/// `0X` or `0x` followed by one or more hexadecimal digits that may
/// include a decimal point.
///
/// let f = ${Self}("0x1c.6")
/// // f == 28.375
///
/// A hexadecimal string may also include an exponent
/// indicating the power of 2 by which the significand should
/// be multiplied. If included, the exponent is separated by a single
/// character, `p` or `P`, and consists of an optional plus or minus sign
/// character and a sequence of decimal digits.
///
/// let g = ${Self}("0x1.c6p4")
/// // g == 28.375
///
/// - The input strings `"inf"` or `"infinity"` (case insensitive)
/// are converted to an infinite result:
///
/// let i = ${Self}("inf")
/// // i == ${Self}.infinity
///
/// let j = ${Self}("-Infinity")
/// // j == -${Self}.infinity
///
/// - An input string of `"nan"` (case insensitive) is converted
/// into a *NaN* value:
///
/// let n = ${Self}("-nan")
/// // n?.isNaN == true
/// // n?.sign == .minus
///
/// A NaN string may also include a payload in parentheses following the
/// `"nan"` keyword. The payload consists of a sequence of decimal digits,
/// or the characters `0X` or `0x` followed by a sequence of hexadecimal
/// digits. If the payload contains any other characters, it is ignored.
/// If the value of the payload is larger than can be stored as the
/// payload of a `${Self}.nan`, the least significant bits are used.
///
/// let p = ${Self}("nan(0x10)")
/// // p?.isNaN == true
/// // String(p!) == "nan(0x10)"
///
/// A string in any other format than those described above
/// or containing additional characters
/// results in a `nil` value. For example, the following conversions
/// result in `nil`:
///
/// ${Self}(" 5.0") // Includes whitespace
/// ${Self}("±2.0") // Invalid character
/// ${Self}("0x1.25e4") // Incorrect exponent format
///
/// A decimal or hexadecimal string is converted to a `${Self}`
/// instance using the IEEE 754 roundTiesToEven (default) rounding
/// attribute.
/// Values with absolute value smaller than `${Self}.leastNonzeroMagnitude`
/// are rounded to plus or minus zero.
/// Values with absolute value larger than `${Self}.greatestFiniteMagnitude`
/// are rounded to plus or minus infinity.
///
/// let y = ${Self}("1.23e-9999")
/// // y == 0.0
/// // y?.sign == .plus
///
/// let z = ${Self}("-7.89e-7206")
/// // z == -0.0
/// // z?.sign == .minus
///
/// let r = ${Self}("1.23e17802")
/// // r == ${Self}.infinity
///
/// let s = ${Self}("-7.89e7206")
/// // s == ${Self}.-infinity
///
/// - Note: Prior to Swift 5.4, a decimal or
/// hexadecimal input string whose value was too large to represent
/// as a finite `${Self}` instance returned `nil` instead of
/// `${Self}.infinity`.
///
/// - Parameter text: An input string to convert to a `${Self}?` instance.
///
@inlinable
public init?<S: StringProtocol>(_ text: S) {
%if bits == 16:
self.init(Substring(text))
%else:
if #available(macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0, *) { //SwiftStdlib 5.3
self.init(Substring(text))
} else {
self = 0.0
let success = withUnsafeMutablePointer(to: &self) { p -> Bool in
text.withCString { chars -> Bool in
switch chars[0] {
case 9, 10, 11, 12, 13, 32:
return false // Reject leading whitespace
case 0:
return false // Reject empty string
default:
break
}
let endPtr = _swift_stdlib_strto${cFuncSuffix2[bits]}_clocale(chars, p)
// Succeed only if endPtr points to end of C string
return endPtr != nil && endPtr![0] == 0
}
}
if !success {
return nil
}
}
%end
}
// Caveat: This implementation used to be inlineable.
// In particular, we still have to export
// _swift_stdlib_strtoXYZ_clocale()
// as ABI to support old compiled code that still requires it.
@available(SwiftStdlib 5.3, *)
public init?(_ text: Substring) {
self = 0.0
let success = withUnsafeMutablePointer(to: &self) { p -> Bool in
text.withCString { chars -> Bool in
switch chars[0] {
case 9, 10, 11, 12, 13, 32:
return false // Reject leading whitespace
case 0:
return false // Reject empty string
default:
break
}
let endPtr = _swift_stdlib_strto${cFuncSuffix2[bits]}_clocale(chars, p)
// Succeed only if endPtr points to end of C string
return endPtr != nil && endPtr![0] == 0
}
}
if !success {
return nil
}
}
}
% if bits in [16,80]:
#endif
% end
% end
// ${'Local Variables'}:
// eval: (read-only-mode 1)
// End: