expr_t parse_relat_expr(tokenizer_t t) {
char * filename = cur_tok(t).filename;
int line = cur_tok(t).line_num;
expr_t e = parse_add_expr(t);
while((cur_tok(t).kind==TOK_LT)|(cur_tok(t).kind==TOK_GT)|(cur_tok(t).kind==TOK_LE)|(cur_tok(t).kind==TOK_GE)) {
op_kind_t op = parse_relat_oper(t);
expr_t e0 = parse_add_expr(t);
e = mk_expr_bin_op(filename, line, op, e, e0);
}
return e;
}
// order_rest := ... (< | <= | > | >=) add_expr (order_rest)
Expr*
parse_order_rest(Parser& p, Token_stream& ts, Token const* tok, Expr* e1)
{
if (Expr* e2 = parse_add_expr(p, ts)) {
if (Token const* t = ts.next()) {
// keep parsing the 'rest' while we still have a valid operator
if (t->kind() == less_tok
|| t->kind() == less_eq_tok
|| t->kind() == great_tok
|| t->kind() == great_eq_tok)
return parse_order_rest(p, ts, ts.advance(), p.on_binary(tok, e1, e2));
else
return p.on_binary(tok, e1, e2);
}
return p.on_binary(tok, e1, e2);
}
error("Expected expression after logical-or expr: ");
print(e1);
print(tok);
print("\n");
return nullptr;
}
expr_t parse_relat_expr(tokenizer_t t){
expr_t expr_left, expr_right;
expr_left = parse_add_expr(t);
struct token tok = cur_tok(t);
// relational-operator
while(tok.kind == TOK_LT || tok.kind == TOK_GT || tok.kind == TOK_LE || tok.kind == TOK_GE){
eat_it(t, TOK_ANY); // なんでも食べる
expr_right = parse_add_expr(t);
op_kind_t op_kind;
if(tok.kind == TOK_LT) op_kind = op_kind_lt;
if(tok.kind == TOK_GT) op_kind = op_kind_gt;
if(tok.kind == TOK_LE) op_kind = op_kind_le;
if(tok.kind == TOK_GE) op_kind = op_kind_ge;
expr_left = mk_expr_bin_op(t->filename, t->line,
op_kind, expr_left, expr_right); // left にたたんでいく
tok = cur_tok(t);
}
return expr_left;
// struct token tok = cur_tok(t);
// expr_list_t list = mk_expr_list();
// expr_list_add(list, parse_add_expr(t));
// while(1)
// {
// if(tok.kind == TOK_LT || tok.kind == TOK_GT || tok.kind == TOK_LE || tok.kind == TOK_GE)
// {
// eat_it(t, TOK_ANY); // なんでも食べる
// expr_list_add(list, parse_add_expr(t));
// }
// else break;
// }
// expr_t expr = ;
}
// order_expr := order_expr (< | <= | > | >=) add_expr
// add_expr
//
// order_expr := add_expr (order_rest)
Expr*
parse_order_expr(Parser& p, Token_stream& ts)
{
if (Expr* e1 = parse_add_expr(p, ts)) {
if (Token const* tok = ts.next()) {
switch (tok->kind()) {
// advance past the operator and move to parse the 'rest' of the expr
case less_tok:
case less_eq_tok:
case great_tok:
case great_eq_tok:
return parse_order_rest(p, ts, ts.advance(), e1);
default:
return e1;
}
}
return e1;
}
return nullptr;
}
