| 1 | using System.Collections.Concurrent; |
| 2 | using Eto.Parse; |
| 3 | using Eto.Parse.Parsers; |
| 4 | |
| 5 | namespace CascadeIDE.Services.Presentation; |
| 6 | |
| 7 | /// <summary> |
| 8 | /// Внутренняя грамматика одного экрана <c>( … )</c> через <see cref="Eto.Parse"/> (Fluent API, семантика как в EBNF ADR 0017). |
| 9 | /// Внешний уровень (несколько <c>(screen)</c>, разделители между экранами) — по-прежнему в <see cref="PresentationParser"/>. |
| 10 | /// </summary> |
| 11 | internal static class PresentationInnerEtoGrammar |
| 12 | { |
| 13 | private static readonly ConcurrentDictionary<PresentationGrammarTokens, Grammar> Cache = new(); |
| 14 | |
| 15 | /// <summary>Собирает грамматику «якорь с опциональным весом», повторённую через <see cref="PresentationGrammarTokens.ZoneSeparator"/>.</summary> |
| 16 | public static Grammar GetOrCreate(PresentationGrammarTokens grammar) |
| 17 | { |
| 18 | return Cache.GetOrAdd(grammar, Build); |
| 19 | } |
| 20 | |
| 21 | private static Grammar Build(PresentationGrammarTokens g) |
| 22 | { |
| 23 | var zoneSep = Terminals.Literal(g.ZoneSeparator); |
| 24 | var anchor = BuildAnchorChoice(g).Named("anchor"); |
| 25 | |
| 26 | var digit = Terminals.Digit; |
| 27 | var intPart = digit.Repeat(1); |
| 28 | var frac = Terminals.Literal(".").Then(digit.Repeat(1)); |
| 29 | var weight = intPart.Then(frac.Optional()).Named("weight"); |
| 30 | |
| 31 | var weighted = weight.Optional().Then(anchor).Named("slot"); |
| 32 | |
| 33 | var inner = weighted.Then(new RepeatParser(zoneSep.Then(weighted), 0)); |
| 34 | |
| 35 | var rule = inner.Then(Terminals.End); |
| 36 | // Без CharacterSetAlternations: иначе Eto.Parse 1.6.0 схлопывает P|F|M в один CharSet и падает в CharSetTerminal.Test. |
| 37 | return new Grammar(rule) |
| 38 | { |
| 39 | CaseSensitive = true, |
| 40 | EnableMatchEvents = false, |
| 41 | Optimizations = GrammarOptimizations.All & ~GrammarOptimizations.CharacterSetAlternations, |
| 42 | }; |
| 43 | } |
| 44 | |
| 45 | /// <summary>Длинные литералы первыми, затем односимвольные (как <see cref="PresentationParser"/>).</summary> |
| 46 | private static Parser BuildAnchorChoice(PresentationGrammarTokens g) |
| 47 | { |
| 48 | var pairs = new (string Token, PresentationAnchorKind K)[] |
| 49 | { |
| 50 | (g.PfdZoneIdentifier, PresentationAnchorKind.Pfd), |
| 51 | (g.ForwardZoneIdentifier, PresentationAnchorKind.Forward), |
| 52 | (g.MfdZoneIdentifier, PresentationAnchorKind.Mfd), |
| 53 | }; |
| 54 | |
| 55 | Array.Sort(pairs, static (a, b) => b.Token.Length.CompareTo(a.Token.Length)); |
| 56 | |
| 57 | Parser? chain = null; |
| 58 | foreach (var (token, _) in pairs) |
| 59 | { |
| 60 | if (token.Length == 0) |
| 61 | continue; |
| 62 | |
| 63 | Parser p = token.Length == 1 |
| 64 | ? Terminals.Set(char.ToUpperInvariant(token[0]), char.ToLowerInvariant(token[0])) |
| 65 | : Terminals.Literal(token); |
| 66 | |
| 67 | chain = chain is null ? p : chain.Or(p); |
| 68 | } |
| 69 | |
| 70 | return chain ?? Terminals.Set('\uFFFF'); |
| 71 | } |
| 72 | } |
| 73 | |