// <postfix-exp> ::= <primary>
// | <postfix-exp> '(' <arg-list> ')'
// | <postfix-exp> '[' <expr> ']'
private static AstExpression ParsePostfix(TokenStream tks)
{
var si = tks.SourceInfo;
var save = tks.Index;
var expr = ParsePrimary(tks);
if (expr == null)
{
tks.Restore(save);
return(null);
}
Token tk;
while ((tk = tks.Accept(TokenType.Dot, TokenType.LParen, TokenType.LSquBracket)) != null)
{
switch (tk.Type)
{
case TokenType.Dot:
var memberIdent = tks.Expect(TokenType.Ident).StringValue;
expr = new AstMemberAccess(si, expr, memberIdent);
break;
case TokenType.LParen:
expr = new AstCall(si, expr, ParseExpressionList(tks));
tks.Expect(TokenType.RParen);
break;
case TokenType.LSquBracket:
tks.ThrowIfTokenIs(TokenType.RSquBracket);
expr = new AstIndex(si, expr, ParseExpressionList(tks));
tks.Expect(TokenType.RSquBracket);
break;
}
}
return(expr);
}
private void CompileIndex(AstIndex node, Syt syt, StringBuilder sb)
{
CompileRecursive(node.exprLeft, syt, sb);
CompileRecursive(node.exprRight, syt, sb);
sb.AppendLine("add");
sb.AppendLine("pop pointer 1");
sb.AppendLine("push that 0");
}
private AstExpr ParseRef()
{
AstExpr varRef = new AstVarRef {StName = Expect(Ktoken.Id).St};
if (Accept(Ktoken.Lbracket))
{
var astIndex = new AstIndex { exprLeft = varRef, exprRight = ParseExpr() };
Expect(Ktoken.Rbracket);
return astIndex;
}
if (Accept(Ktoken.Dot))
{
var varRefRight = new AstVarRef { StName = Expect(Ktoken.Id).St };
varRef = new AstDot { varLeft = (AstVarRef)varRef, varRight = varRefRight };
}
if (FCurrent(Ktoken.Lparen))
return new AstCall { exprFunc = varRef, rgexprParam = ParseArgumentList().ToArray() };
return varRef;
}
