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Make importer protocol.

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This commit is contained in:
Sven Weidauer 2022-10-08 11:03:28 +02:00
parent e6f44f5be2
commit e28bee804f
4 changed files with 45 additions and 26 deletions
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213
Sources/LibMakeColors/Model/Scanner+ColorParser.swift
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@ -1,213 +0,0 @@
import Foundation
extension Scanner {
func color() -> Color? {
if string("#"), let digits = scanCharacters(from: .hex) {
switch digits.count {
case 3, 4: // rgb(a)
let digits = digits.chunks(size: 1)
.compactMap { UInt8($0, radix: 16) }
.map { $0 << 4 | $0 }
return Color(digits)
case 6, 8: // rrggbb(aa)
let digits = digits.chunks(size: 2).compactMap { UInt8($0, radix: 16) }
return Color(digits)
default:
return nil
}
}
if string("rgba"), let components = argumentList(4) {
return Color(components)
}
if string("rgb"), let components = argumentList(3) {
return Color(components)
}
if string("white"), let arguments = argumentList(min: 1, max: 2) {
return Color(white: arguments)
}
if string("hsva") {
return readHSV(alpha: true)
}
if string("hsv") {
return readHSV(alpha: false)
}
return nil
}
private func readHSV(alpha readAlpha: Bool) -> Color? {
guard
string("("),
let hue = degrees(),
string(","),
let saturation = component(),
string(","),
let value = component()
else { return nil }
let alpha: UInt8
if readAlpha {
guard
string(","),
let value = component()
else { return nil }
alpha = value
} else {
alpha = 0xFF
}
guard string(")") else { return nil }
return Color(hue: hue, saturation: saturation, value: value, alpha: alpha)
}
func degrees() -> Int? {
guard let int = scanInt() else { return nil }
if string("%") {
guard 0...100 ~= int else { return nil }
return (360 * int) / 100
} else if string("°") || string("deg") {
return int
} else {
guard 0...0xFF ~= int else { return nil }
return (360 * int) / 0xFF
}
}
func colorReference() -> String? {
guard string("@") else { return nil }
return name()
}
func name() -> String? {
guard let name = scanCharacters(from: .name), !name.isEmpty else {
return nil
}
return name
}
func colorDef() -> ColorDef? {
if let color = color() {
return .color(color)
}
if let ref = colorReference() {
return .reference(ref)
}
return nil
}
func colorLine() -> (String, ColorDef)? {
guard
let name = self.name(),
let def = colorDef(),
endOfLine()
else {
return nil
}
return (name, def)
}
func endOfLine() -> Bool {
guard isAtEnd || string("\n") else {
return false
}
_ = scanCharacters(from: .whitespacesAndNewlines)
return true
}
func colorList() throws -> [String: ColorDef] {
var result: [String: ColorDef] = [:]
while !isAtEnd {
guard let (name, def) = colorLine() else {
throw Errors.syntaxError
}
guard !result.keys.contains(name) else {
throw Errors.duplicateColor(name)
}
result[name] = def
}
return result
}
// swiftlint:disable:next discouraged_optional_collection
func argumentList(_ count: Int) -> [UInt8]? {
argumentList(min: count, max: count)
}
// swiftlint:disable:next discouraged_optional_collection
func argumentList(min: Int, max: Int? = nil) -> [UInt8]? {
let max = max ?? Int.max
guard
string("("),
let arguments = commaSeparated(),
string(")"),
(min...max) ~= arguments.count
else {
return nil
}
return arguments
}
// swiftlint:disable:next discouraged_optional_collection
func commaSeparated() -> [UInt8]? {
var result: [UInt8] = []
repeat {
guard let component = self.component() else {
return nil
}
result.append(component)
} while string(",")
return result
}
func component() -> UInt8? {
guard var int = scanInt() else {
return nil
}
if string("%") {
guard 0...100 ~= int else { return nil }
int = int * 0xFF / 100
}
return UInt8(exactly: int)
}
}
private extension Scanner {
func string(_ string: String) -> Bool {
scanString(string) != nil
}
}
private extension CharacterSet {
static let hex = CharacterSet(charactersIn: "0123456789abcdefABCDEF")
static let name = alphanumerics.union(CharacterSet(charactersIn: "_/"))
}
private extension Collection {
func chunks(size: Int) -> UnfoldSequence<Self.SubSequence, Self.Index> {
sequence(state: startIndex) { state -> SubSequence? in
guard state != endIndex else { return nil }
let next = index(state, offsetBy: size, limitedBy: endIndex) ?? endIndex
defer { state = next }
return self[state..<next]
}
}
}