/// <summary>Parses a sequence of Kaleidoscope source text into AST nodes</summary>
/// <param name="source">source sequence of expressions</param>
/// <param name="parser">Kaleidoscope parser stack to parse the input</param>
/// <param name="errorHandler">Handler for AST Generation errors</param>
/// <returns>Observable sequence of AST nodes</returns>
/// <remarks>
/// This explicitly swallows <see cref="CodeGeneratorException"/> that occur during parse by
/// calling the <paramref name="errorHandler"/> to report the error and
/// producing nothing. This allows for a more robust sequence as user input errors are
/// expected to occur and shouldn't stop the complete sequence.
/// </remarks>
public static IObservable <IAstNode> ParseWith(this IObservable <string> source
, IKaleidoscopeParser parser
, Action <CodeGeneratorException> errorHandler
)
{
return(from expression in source
let node = ParseAndReportErrors(expression, parser, errorHandler)
where node != null
select node);
}
private static IAstNode ParseAndReportErrors(string expression
, IKaleidoscopeParser parser
, Action <CodeGeneratorException> codeGeneratorExceptionHandler
)
{
try
{
return(parser.Parse(expression));
}
catch (CodeGeneratorException ex)
{
codeGeneratorExceptionHandler(ex);
return(null);
}
}
