public GrammarResult Grammar()
{
GrammarResult result = new GrammarResult();
foreach (Production production in Compiler.Parser.Grammar.Instance)
{
ProductionModel productionModel = new ProductionModel {
Head = production.Identifier
};
production.ForEach(x =>
{
productionModel.SubProductions.Add(new SubProductionModel
{
Expressions = x.Select(y => new ExpressionModel
{
Name = y.ToString(),
IsNonTerminalExpression = y is NonTerminalExpressionDefinition
}).ToList()
});
});
result.Productions.Add(productionModel);
}
return(result);
}
public static SearchResult <T> FilterUsingAntlr <T>(
this IQueryable <T> query,
string queryString,
params Expression <Func <T, string> >[] properties)
{
if (query == null)
{
throw new ArgumentNullException("query");
}
if (properties == null)
{
throw new ArgumentNullException("properties");
}
if (properties.Length == 0)
{
throw new ArgumentException("At least one property is expected", "properties");
}
if (string.IsNullOrWhiteSpace(queryString))
{
return(new SearchResult <T>(query, Enumerable.Empty <string>()));
}
AntlrInputStream input = new AntlrInputStream(queryString);
SearchGrammarLexer lexer = new SearchGrammarLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
SearchGrammarParser parser = new SearchGrammarParser(tokens);
IParseTree parseTree = parser.prog();
var arg = Expression.Parameter(typeof(T), "p");
MemberExpression[] memberExpressions = new MemberExpression[properties.Length];
for (int i = 0; i < properties.Length; i++)
{
var propertyMemberExpression = properties[i].Body as MemberExpression;
if (propertyMemberExpression == null)
{
throw new ArgumentException(
"The " + i + "th property is invalid. Please provide property member expression like 'o => o.Name'",
"properties");
}
string propertyString = propertyMemberExpression.ToString();
string name = propertyString.Substring(propertyString.IndexOf('.') + 1);
memberExpressions[i] = Expression.Property(arg, name);
}
#if DEBUG
string treeText = new StringBuilderVisitor().Visit(parseTree);
System.Diagnostics.Trace.WriteLine(treeText);
#endif
GrammarResult searchResult = null;
try
{
ExpressionBuilderVisitor visitor = new ExpressionBuilderVisitor(memberExpressions);
searchResult = visitor.Visit(parseTree);
}
catch (InvalidSearchException)
{
string failedTreeText = new StringBuilderVisitor().Visit(parseTree);
System.Diagnostics.Trace.WriteLine("Failed to parse search grammar '" + queryString + "': \r\n" + failedTreeText);
throw;
}
var searchPredicate = Expression.Lambda <Func <T, bool> >(searchResult.Expression, arg);
return(new SearchResult <T>(query.Where(searchPredicate), searchResult.Terms));
}
