// Parse a postfix expression.
//
// postfix-expression -> postfix-expression '(' argument-list ')'
// | postfix-expression '[' expression ']'
// | postfix-expression . identifier
// | primary-expression
Expr*
Parser::postfix_expr()
{
Expr* e1 = primary_expr();
while (true) {
// dot-expr
if (match_if(dot_tok)) {
Token tok = match(identifier_tok);
Expr* e2 = on_id(tok);
e1 = on_dot(e1, e2);
}
// call-expr
else if (match_if(lparen_tok)) {
Expr_seq args;
while (lookahead() != rparen_tok) {
args.push_back(expr());
if (match_if(comma_tok))
continue;
else
break;
}
match(rparen_tok);
e1 = on_call(e1, args);
}
// index-expr
else if (match_if(lbrack_tok)) {
Expr* e2 = expr();
match(rbrack_tok);
e1 = on_index(e1, e2);
}
// anything else
else {
break;
}
}
return e1;
}
static int unary_expr(ParserState* ps, Ast** expr) {
Ast* start = ps->curr;
if (curris(ps, OpSub) || curris(ps, OpNot)) {
if (curris(ps, OpSub))
ps->curr->t = OpNeg;
Ast* op = ps->curr;
step(ps);
if (unary_expr(ps, expr)) {
ast_next_to_first_child(op);
*expr = op;
}
else {
parerr(ps, "invlaid syntax");
}
return 1;
}
else if (primary_expr(ps, expr)) { return 1; }
ps->curr = start;
return 0;
}