Skip to content

Commit

Permalink
Fix parsing of newlines in engine responses (chesskit-app#14)
Browse files Browse the repository at this point in the history 
* If engine response contained a newline character (`\n`), parsing would
fail as the newline character would be included in the token.
* Parsing now strips out newlines when tokenizing the response.
  • Loading branch information
@pdil
pdil authored Apr 23, 2024
2 parents 5e3a3a5 + 6c78849 commit 7d01c84
Show file tree
Hide file tree
Showing 3 changed files with 88 additions and 88 deletions.
5 changes: 5 additions & 0 deletions CHANGELOG.md
View file
Original file line number Diff line number Diff line change
@@ -1,3 +1,8 @@
# [unreleased]

#### Bug Fixes
* Fix issue where engine responses containing a newline character would not be parsed correctly.

# ChessKitEngine 0.4.0
Released Monday, April 22, 2024.

Expand Down
125 changes: 54 additions & 71 deletions Sources/ChessKitEngine/EngineResponse/EngineResponseParser.swift
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,17 +4,17 @@
//

class EngineResponseParser {

private init() {}

static func parse(response: String) -> EngineResponse? {
let tokens = response.split(separator: " ").map(String.init)
let tokens = response.split { $0.isWhitespace || $0.isNewline } .map(String.init)
var iterator = tokens.makeIterator()

guard let command = iterator.next() else {
return nil
}

switch command {
case "id": return parseID(&iterator)
case "uciok": return .uciok
Expand All @@ -24,76 +24,76 @@ class EngineResponseParser {
default: return nil
}
}

// MARK: - Private

private static func parseID(_ iterator: inout IndexingIterator<[String]>) -> EngineResponse? {
switch iterator.next() {
case "name": return .id(.name(iterator.joined(separator: " ")))
case "author": return .id(.author(iterator.joined(separator: " ")))
default: return nil
}
}

private static func parseBestMove(_ iterator: inout IndexingIterator<[String]>) -> EngineResponse? {
guard let move = iterator.next() else { return nil }

var ponder: String?
if iterator.next() == "ponder" {
ponder = iterator.next()
}

return .bestmove(move: move, ponder: ponder)
}

private static func parseInfo(_ iterator: inout IndexingIterator<[String]>) -> EngineResponse? {
let arguments = EngineResponse.Info.Argument.allCases
// possible sub-arguments for <score> argument
let scoreSubArguments = ["cp", "mate"]

var info = EngineResponse.Info()
var score: EngineResponse.Info.Score?
var currLine: EngineResponse.Info.CurrLine?

var activeArg: String?
var activeScoreSubArg: String?
var multiArgCollection: [String] = []

var token = iterator.next()

while token != nil {

if let token,
activeArg == nil,
arguments.map(\.rawValue).contains(token) {

activeArg = token

} else if let token,
let active = activeArg,
arguments.map(\.rawValue).contains(token) {

// A new valid argument has been reached,
// set "in progress" structures accordingly
// and clean up / reset
if !multiArgCollection.isEmpty {
info[active] = map(multiArgCollection, for: active)
multiArgCollection = []
}

if currLine != nil {
info[active] = map(currLine, for: active)
currLine = nil
}

if score != nil {
info[active] = map(score, for: active)
score = nil
}

// Set active argument to the new token
activeArg = token

} else if let active = activeArg, let token {
if let type = EngineResponse.Info.Argument(rawValue: active)?.type {
switch type {
Expand All @@ -105,26 +105,26 @@ class EngineResponseParser {
case .string:
var stringTokens = [token]
var subtoken = iterator.next()

// consume rest of iterator for `string`
while subtoken != nil {
if let subtoken {
stringTokens.append(subtoken)
}

subtoken = iterator.next()
}

info[active] = stringTokens.joined(separator: " ")
case .score:
if score == nil {
score = .init()
}

if ["lowerbound", "upperbound"].contains(token) {
score?[token] = true
}

if scoreSubArguments.contains(token) {
activeScoreSubArg = token
} else if let activeScore = activeScoreSubArg {
Expand All @@ -136,7 +136,7 @@ class EngineResponseParser {
default:
break
}

activeScoreSubArg = nil
}
case .currentLine:
Expand All @@ -149,72 +149,55 @@ class EngineResponseParser {
}
}
}

token = iterator.next()
}

// populate any "in progress" structures that
// did not have a chance to be added to `info`
if let activeArg {
if !multiArgCollection.isEmpty {
info[activeArg] = map(multiArgCollection, for: activeArg)
}

if currLine != nil {
info[activeArg] = map(currLine, for: activeArg)
}

if score != nil {
info[activeArg] = map(score, for: activeArg)
}
}

return .info(info)
}

/// Maps `value` to appropriate type depending on `key`.
private static func map(_ value: Any?, for key: String) -> Any? {
guard let argument = EngineResponse.Info.Argument(rawValue: key),
let value else {
return nil
}

switch argument {
case .depth:
return Int(value as? String ?? "")
case .seldepth:
return Int(value as? String ?? "")
case .time:
return Int(value as? String ?? "")
case .nodes:
return Int(value as? String ?? "")
case .pv:
return value as? [String]
case .multipv:
return Int(value as? String ?? "")
case .score:
return value as? EngineResponse.Info.Score
case .currmove:
return value as? String
case .currmovenumber:
return Int(value as? String ?? "")
case .hashfull:
return Double(value as? String ?? "")
case .nps:
return Int(value as? String ?? "")
case .tbhits:
return Int(value as? String ?? "")
case .sbhits:
return Int(value as? String ?? "")
case .cpuload:
return Int(value as? String ?? "")
case .string:
return value as? String
case .refutation:
return value as? [String]
case .currline:
return value as? EngineResponse.Info.CurrLine
case .depth: return Int(value as? String ?? "")
case .seldepth: return Int(value as? String ?? "")
case .time: return Int(value as? String ?? "")
case .nodes: return Int(value as? String ?? "")
case .pv: return value as? [String]
case .multipv: return Int(value as? String ?? "")
case .score: return value as? EngineResponse.Info.Score
case .currmove: return value as? String
case .currmovenumber: return Int(value as? String ?? "")
case .hashfull: return Double(value as? String ?? "")
case .nps: return Int(value as? String ?? "")
case .tbhits: return Int(value as? String ?? "")
case .sbhits: return Int(value as? String ?? "")
case .cpuload: return Int(value as? String ?? "")
case .string: return value as? String
case .refutation: return value as? [String]
case .currline: return value as? EngineResponse.Info.CurrLine
}
}

}
Loading

0 comments on commit 7d01c84

Please sign in to comment.