C99's brain-dead

[jacktby jacktby]

[image: 1664711612742.png]
can you explain this please?

what is brain-dead about C99 inline functions?

[jacktby jacktby]

Please explain what's c99 brain dead?

[jacktby jacktby]

 can you give me a link to study it?

How does pg parse 'select '(1,2)''

[jacktby jacktby]

I’m trying to add new grammar for my application. So I’m do research on gram.y.
I think it will make the '(1,2)' as " '(' a_expr ')' "; but I can’t find out 
something like
" a_expr ',' a_expr “, can you give me the details?

Failed to parse new syntax

[jacktby jacktby]

/*
*   similarity_search_expr is used for our multi-mode 
*   similarity_search, and we just use this for multi
*   cols search.
*/
similarity_search_expr: 
sub_search_expr '<' AexprConst {
$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $3, @2);
}
;
sub_search_expr:
'[' col_tuple_expr '~' AexprConst ']' {
$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~", $2, $4, @3);
}
;
col_tuple_expr:
columnref { $$ = $1;}
| '(' col_list_expr ')' { $$ = $2;}
;
col_list_expr:
columnref {
ResTarget* target = makeNode(ResTarget);
target->name = NULL;
target->indirection = NIL;
target->val = (Node *) $1;
target->location = @1;
$$ = list_make1(target);
}
| col_list_expr ',' columnref { $$ = lappend($1,$3);}
;
This is my new grammer.
But I get  below:
   postgres=# select * from t2 where [a ~ 1] < 0;
   ERROR:  syntax error at or near "~"
 LINE 1: select * from t2 where [a ~ 1] < 0;
It’s strange that it can’t parse ‘~’, I add it in the parser.

./configure doesn't make effect?

[jacktby jacktby]

I use “rm -rf /data”, the ‘/data’ is the prefix when I execute ./configure 
command firstly, but after I ‘rm’ it, and use the command again, I can’t get 
the /data content. Why?

Re: ./configure doesn't make effect?

[jacktby jacktby]

Sorry, I make a mistake, I should make install. That’s my fault

> 2023年9月5日 20:08，Jeremy Garniaux  写道：
> 
> Hi, 
> 
> The command you described:
> 
> Le 05/09/2023 à 13:41, jacktby jacktby a écrit :
>> rm -rf /data
> has for effect to remove the /data directory and all its content. See: 
> https://explainshell.com/explain?cmd=rm+-rf+%2Fdata 
> 
> It explains why you don't get the /data content.
> 
> Jeremy
> 
> Jeremy Garniaux
> https://mapper.fr <https://mapper.fr/>

How to make a map in pg kernel?

[jacktby jacktby]

Hi, I’m writing some kernel codes in pg15, and now I need to make a map struct, 
I know c-lang doesn’t support this, so does pg support an internal struct? 
Hopefully your replies.