SwiftyMarkdownForked/Sources/SwiftyMarkdown/String+SwiftyMarkdown.swift

//
//  String+SwiftyMarkdown.swift
//  SwiftyMarkdown
//
//  Created by Simon Fairbairn on 08/12/2019.
//  Copyright © 2019 Voyage Travel Apps. All rights reserved.
//

import Foundation

/// Some helper functions based on this:
/// https://stackoverflow.com/questions/32305891/index-of-a-substring-in-a-string-with-swift/32306142#32306142
extension StringProtocol {
    func index<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> Index? {
        range(of: string, options: options)?.lowerBound
    }
    func endIndex<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> Index? {
        range(of: string, options: options)?.upperBound
    }
    func indices<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Index] {
        var indices: [Index] = []
        var startIndex = self.startIndex
        while startIndex < endIndex,
            let range = self[startIndex...]
                .range(of: string, options: options) {
                indices.append(range.lowerBound)
                startIndex = range.lowerBound < range.upperBound ? range.upperBound :
                    index(range.lowerBound, offsetBy: 1, limitedBy: endIndex) ?? endIndex
        }
        return indices
    }
	func ranges<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Range<String.Index>] {
        var result: [Range<Index>] = []
        var startIndex = self.startIndex
        while startIndex < endIndex,
            let range = self[startIndex...]
                .range(of: string, options: options) {
                result.append(range)
                startIndex = range.lowerBound < range.upperBound ? range.upperBound :
                    index(range.lowerBound, offsetBy: 1, limitedBy: endIndex) ?? endIndex
        }
        return result
    }
}