public static IObservable <TResult> Parse <TSource, TResult>( this IObservable <TSource> source, Func <ObservableParserQueryContext <TSource, TSource, IObservableParser <TSource, TSource> >, ObservableParserQueryContext <TSource, TSource, IObservableParser <TSource, TResult> > > grammarSelector) { Contract.Requires(source != null); Contract.Requires(grammarSelector != null); Contract.Ensures(Contract.Result <IObservable <TResult> >() != null); var parser = new InlineObservableParser <TSource, TResult>(); var proxyParser = (IObservableParser <TSource, TSource>)parser; // The proxy allows the grammar author to use base methods such as Success and Failure // while still allowing type inference to work correctly; i.e., the Parse method is unavailable // and thus the type of the proxy is based solely on TSource, without requiring TResult to // be in an input position in grammarSelector. var context = new ObservableParserQueryContext <TSource, TSource, IObservableParser <TSource, TSource> >( proxyParser, parser.Next); var grammar = grammarSelector(context); Contract.Assume(grammar != null); IObservableParser <TSource, TResult> start = grammar.Value; Contract.Assume(start != null); // enableBranchOptimizations must be false: See the comments in the first interactive Rxx.Parsers.Linq.Parser.Parse method for details. return(parser.Parse(source.ToCursor(forwardOnly: true, enableBranchOptimizations: false), start)); }
/// <summary> /// Enables defining in-line parser grammars using LINQ. /// </summary> /// <typeparam name="TParseSource">The type of the original source elements.</typeparam> /// <typeparam name="TParseResult">The type of the elements that are originally generated from parsing the source elements.</typeparam> /// <typeparam name="TSource">The type of the source elements; typically, this will be an anonymous compiler-generated type.</typeparam> /// <typeparam name="TResult">The type of the elements that are generated from parsing the source elements.</typeparam> /// <param name="source">The parser query context to be projected.</param> /// <param name="selector">A function that projects the current result of the query context.</param> /// <returns>A new query context that is the projection of the specified query context using the specified <paramref name="selector"/>.</returns> public static ObservableParserQueryContext <TParseSource, TParseResult, TResult> Select <TParseSource, TParseResult, TSource, TResult>( this ObservableParserQueryContext <TParseSource, TParseResult, TSource> source, Func <TSource, TResult> selector) { Contract.Requires(source != null); Contract.Requires(selector != null); Contract.Ensures(Contract.Result <ObservableParserQueryContext <TParseSource, TParseResult, TResult> >() != null); return(new ObservableParserQueryContext <TParseSource, TParseResult, TResult>( source.Parser, selector(source.Value))); }