/// <summary>
/// 評価用メソッド.
/// </summary>
/// <param name="context">コンテキストオブジェクト.</param>
public override void Interpret(EBNFContext context)
{
DebugLog(": RightExpression.Interpret()");
// 戻り値の準備
GeneratedExpression exp = ExpressionFactory.CreateField();
// 最初のトークンをチェック
Token <TokenType> token = context.Current;
CheckTokenExists(token);
CheckFirstToken(token);
bool loop = true;
while (loop)
{
DebugLog(": RightExpression: (" + token.Type + ")");
switch (token.Type)
{
case TokenType.String:
case TokenType.Name:
Token <TokenType> nextToken = token.Next;
if (nextToken != null && nextToken.Type == TokenType.Or)
{
GeneratedExpression orExp = ParseOr(context);
exp.AddExpression(orExp);
token = context.Current;
CheckTokenExists(token);
}
break;
}
if (token.IsLast)
{
//ThrowParseException(ErrorMessages.UnexpectedToken, token);
break;
}
switch (token.Type)
{
case TokenType.String:
exp.AddExpression(
ParseTerminal(context)
);
token = context.Next();
break;
case TokenType.Name:
exp.AddExpression(
ParseNonterminal(context, token.Text)
);
token = context.Next();
break;
case TokenType.OpenParen:
exp.AddExpression(
ParseGroup(context)
);
token = context.Current;
break;
case TokenType.OpenBrace:
exp.AddExpression(
ParseLoop(context)
);
token = context.Current;
break;
case TokenType.OpenBracket:
exp.AddExpression(
ParseOption(context)
);
token = context.Current;
break;
case TokenType.Comma:
CheckComma(token);
token = context.Next();
break;
case TokenType.Semicolon:
loop = false;
break;
default:
ThrowParseException(ErrorMessages.UnexpectedToken, token);
break;
}
CheckTokenExists(token);
if (token.IsLast)
{
break;
}
}
// 戻り値
context.PushExpression(exp);
}