git.r.bdr.sh - rbdr/map/blob - Map/MapParser/Strategies/EdgeParserStrategy.swift

   1 import Foundation
   2
   3 struct EdgeParserStrategy: MapParserStrategy {
   4   private let regex = MapParsingPatterns.edge
   5
   6   func canHandle(line: String) -> Bool {
   7     let range = NSRange(location: 0, length: line.utf16.count)
   8     let matches = regex.matches(in: String(line), options: [], range: range)
   9     return matches.count > 0 && matches[0].numberOfRanges == 4
  10   }
  11
  12   func handle(index: Int, line: String, vertices: [String: Vertex]) -> (Any.Type, Any) {
  13     let range = NSRange(location: 0, length: line.utf16.count)
  14     let matches = regex.matches(in: String(line), options: [], range: range)
  15
  16     let match = matches[0]
  17     let arrowhead = String(line[Range(match.range(at: 2), in: line)!]) == ">"
  18     let vertexA = String(line[Range(match.range(at: 1), in: line)!])
  19     let vertexB = String(line[Range(match.range(at: 3), in: line)!])
  20
  21     if let origin = vertices[vertexA] {
  22       if let destination = vertices[vertexB] {
  23         let edge = MapEdge(
  24           id: index, origin: origin.position, destination: destination.position,
  25           arrowhead: arrowhead)
  26         return (MapEdge.self, edge)
  27       }
  28     }
  29
  30     return (NSObject.self, NSObject())  // No matching object
  31   }
  32 }