//------------------------------------------------------------
/// <summary>
/// PostfixExpression:
/// PrimaryExpression (PostfixOperator)*
///
/// PostfixOperator:
/// "++"
/// | "--"
/// | IndexExpression
/// | FunctionCallExpression
/// | "." Identifier # ChildIdentExpression
/// </summary>
/// <returns></returns>
IExpression parsePostfixExpression()
{
IExpression firstExpr = parsePrimaryExpression();
while (firstExpr != null)
{
PostfixExpression.OpKind opKind = PostfixExpression.OpKind.Unknown;
// OpTokenがある式
Token opToken = currentToken();
if (currentToken().Value == Token.Kind.OpPlusPlus)
{// "++"
opKind = PostfixExpression.OpKind.Inc;
nextToken();
}
else if (currentToken().Value == Token.Kind.OpMinusMinus)
{// "--"
opKind = PostfixExpression.OpKind.Dec;
nextToken();
}
if (opKind != PostfixExpression.OpKind.Unknown)
{
firstExpr = new PostfixExpression(opToken, opKind, firstExpr);
}
// OpTokenがない式
if (currentToken().Value == Token.Kind.OpLBracket)
{// IndexExpression
IndexExpression expr = parseIndexExpression();
if (expr == null)
{
return(null);
}
return(new PostfixExpression(firstExpr, expr));
}
else if (currentToken().Value == Token.Kind.OpLParen)
{// FunctionCallExpression
FunctionCallExpression expr = parseFunctionCallExpression();
if (expr == null)
{
return(null);
}
return(new PostfixExpression(firstExpr, expr));
}
else if (currentToken().Value == Token.Kind.OpDot)
{// ChildIdentExpression
nextToken();
if (currentToken().Value != Token.Kind.Identifier)
{
setErrorKind(ErrorKind.POSTFIX_EXPRESSION_IDENTIFIER_EXPECTED);
return(null);
}
ChildIdentExpression expr = new ChildIdentExpression(new Identifier(currentToken()));
nextToken();
return(new PostfixExpression(firstExpr, expr));
}
else
{
return(firstExpr);
}
}
return(firstExpr);
}
//------------------------------------------------------------
// ChildIdentのコンストラクタ。
public PostfixExpression(IExpression aFirstExpr, ChildIdentExpression aChildIdentExpr)
{
mExprKind = ExprKind.ChildIdentExpr;
mFirstExpr = aFirstExpr;
mChildIdentExpr = aChildIdentExpr;
}