//------------------------------------------------------------
/// <summary>
/// PrimaryExpression:
/// Identifier # ScopeRootIdentExpression
/// | "." Identifier # NamespaceRootIdentExpression
/// | ConstantLiteral
/// | "(" Expression ")"
/// </summary>
/// <returns></returns>
IExpression parsePrimaryExpression()
{
IExpression expr = null;
if (currentToken().Value == Token.Kind.Identifier)
{
expr = new RootIdentExpression(new Identifier(currentToken()), false);
nextToken();
}
else if (currentToken().Value == Token.Kind.OpDot)
{
if (currentToken().Value != Token.Kind.Identifier)
{
setErrorKind(ErrorKind.PRIMARY_EXPRESSION_IDENTIFIER_EXPECTED);
return(null);
}
expr = new RootIdentExpression(new Identifier(currentToken()), true);
nextToken();
}
else if (isConstantLiteral(currentToken()))
{
expr = new ConstantLiteralExpression(currentToken());
nextToken();
}
else
{
// "("
if (!expectToken(Token.Kind.OpLParen, ErrorKind.PRIMARY_EXPRESSION_LPAREN_EXPECTED))
{
return(null);
}
// Expression
expr = parseExpression();
// ")"
if (!expectToken(Token.Kind.OpRParen, ErrorKind.PRIMARY_EXPRESSION_RPAREN_EXPECTED))
{
return(null);
}
}
return(expr);
}
//------------------------------------------------------------
// コンストラクタ。
public EvaluateNode(RootIdentExpression aExpr)
{
mExpr = aExpr;
}