public void TestShiftReduceError()
{
INonTerminal <string> ifStatement = null;
try
{
// This configuration is not a valid LR1 parser. It contains shift reduce conflicts
// clasical dangling else case
var configurator = ParserFactory.Configure <string>();
var ident = configurator.CreateTerminal("[a-z]+");
ident.DebugName = "ident";
ifStatement = configurator.CreateNonTerminal();
ifStatement.DebugName = "ifStatement";
var statement = configurator.CreateNonTerminal();
statement.DebugName = "statement";
ifStatement.AddProduction("if", "\\(", ident, "\\)", "then", statement);
ifStatement.AddProduction("if", "\\(", ident, "\\)", "then", statement, "else", statement);
statement.AddProduction(ifStatement);
statement.AddProduction(ident, "=", ident);
configurator.LexerSettings.CreateLexer = false;
configurator.CreateParser();
Assert.Fail("No exception for ambiguous grammar");
}
catch (ShiftReduceConflictException <string> e)
{
Assert.AreEqual(ifStatement, e.ReduceSymbol);
Assert.AreEqual("else", e.ShiftSymbol.DebugName);
}
}
public void TestACalculator()
{
// This is a full on integration test that builds a parser and performs a simple calculation.
var configurator = ParserFactory.Configure <int>();
ITerminal <int> number = configurator.CreateTerminal("\\d+", int.Parse);
number.DebugName = "number";
INonTerminal <int> expr = configurator.CreateNonTerminal();
expr.DebugName = "expr";
INonTerminal <int> term = configurator.CreateNonTerminal();
term.DebugName = "term";
INonTerminal <int> factor = configurator.CreateNonTerminal();
factor.DebugName = "factor";
expr.AddProduction(expr, "+", term).SetReduceFunction(s => s[0] + s[2]);
expr.AddProduction(expr, "-", term).SetReduceFunction(s => s[0] - s[2]);
expr.AddProduction(term).SetReduceFunction(s => s[0]);
term.AddProduction(term, "*", factor).SetReduceFunction(s => s[0] * s[2]);
term.AddProduction(term, "/", factor).SetReduceFunction(s => s[0] / s[2]);
term.AddProduction(factor).SetReduceFunction(s => s[0]);
factor.AddProduction(number).SetReduceFunction(s => s[0]);
factor.AddProduction("(", expr, ")").SetReduceFunction(s => s[1]);
var parser = configurator.CreateParser();
int result = parser.Parse(new StringReader("2-2-5"));
Assert.AreEqual(-5, result);
}
public void TestCanMultiplyDefineTerminalStringsInConfiguration()
{
var configurator = ParserFactory.Configure <int>();
INonTerminal <int> nonTerminal = configurator.CreateNonTerminal();
nonTerminal.DebugName = "NonTerm";
nonTerminal.AddProduction("this", "is", "a", "string");
nonTerminal.AddProduction("this", "is", "a", "test");
var parser = configurator.CreateParser();
Assert.IsNotNull(parser);
}
public void TestReduceReduceConflict()
{
// Represents the grammar
//
// x := t | y
// t := "A"
// y := "A"
//
INonTerminal <object> y = null, t = null;
try
{
var configurator = ParserFactory.Configure <object>();
INonTerminal <object> x = configurator.CreateNonTerminal();
x.DebugName = "X";
t = configurator.CreateNonTerminal();
t.DebugName = "T";
y = configurator.CreateNonTerminal();
y.DebugName = "Y";
x.AddProduction(t);
x.AddProduction(y);
t.AddProduction("A");
y.AddProduction("A");
configurator.CreateParser();
Assert.Fail();
}
catch (ReduceReduceConflictException <object> e)
{
Assert.AreEqual(y, e.NewReduceSymbol);
Assert.AreEqual(t, e.PreviousReduceSymbol);
}
}
public static void AddReduceProduction <T>(this INonTerminal <T> symb, params object[] args) => symb.AddProduction(args).SetReduceToFirst();
public ProductionWrapper <TResult> Add()
{
return(new ProductionWrapper <TResult>(_nonTerminal.AddProduction()));
}
