public void ParserShouldHandleSimpleExpressions()
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream("3*(5+2)"));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
parser.expression();
}
public CommonTree Parse(string expression)
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream(expression));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
return((CommonTree)parser.expression().Tree);
}
protected CommonTree Parse(string expression)
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream(expression));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
try
{
RuleReturnScope rule = parser.expression();
if (parser.HasError)
{
//modify by wsl to translate
//throw new EvaluationException(parser.ErrorMessage + " " + parser.ErrorPosition);
throw new EvaluationException("语法严重错误，系统无法解释计算公式表达式");
}
return(rule.Tree as CommonTree);
}
catch (EvaluationException)
{
throw;
}
catch (Exception e)
{
throw new EvaluationException(e.Message, e);
}
}
public void ParserShouldHandleTree()
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream(" 2 * (3 + 5)"));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
CommonTree tree = (CommonTree)parser.expression().Tree;
Console.WriteLine(tree.ToStringTree());
}
public void ParserShouldHandleTree()
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream(" 2 * (3 + 5)"));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
CommonTree tree = (CommonTree)parser.expression().Tree;
//Console.WriteLine(tree.ToStringTree());
//modify by wsl
Assert.AreEqual("(* 2 (+ 3 5))", tree.ToStringTree());
}
public void ParserShouldHandleBasExpressions()
{
ECalcLexer lexer = new ECalcLexer(new ANTLRStringStream("3*(5+2"));
ECalcParser parser = new ECalcParser(new CommonTokenStream(lexer));
try
{
parser.expression();
Assert.Fail();
}
catch (Exception e)
{
Console.Error.WriteLine("Parser exception: " + e.Message);
}
}