Re: pg_get_triggerdef in pg_dump - Mailing list pgsql-hackers

Great.  I recommend using spaces rather than tabs for indenting in psql
and pg_dump.

---------------------------------------------------------------------------

Andreas Pflug wrote:
> 
> 
> Bruce Momjian wrote:
> 
> >OK, added to TODO:
> >
> >    Modify pg_get_triggerdef() to take a boolean to pretty-print,
> >    and use that as part of pg_dump along with psql
> >
> >Andreas, can you work on this?  I like the idea of removing extra
> >parens, and merging it into the existing code rather than into contrib
> >makes sense.
> >
> 
> Yes, I can. At the moment, I have a runnable contrib module, which 
> replaces all pg_get_xxxdef by pg_get_xxxdef2 functions. It's no problem 
> to apply that code back to the original ruleutils.c when the 
> isSimpleNode algorithm is reviewed independently and proved being correct.
> 
> For safety reasons, I can make this dependent on a bool pretty-print 
> parameter.
> 
> I also could implement line break and indentation formatting. I 
> implemented a keyword-based algorithm in pgAdmin3, and having the 
> original tree the job is obviously easier. Do we need any flexibility 
> about indent char (tab or space) and indentation size (2 chars)? The 
> pgAdmin3 algorithm uses 4 spaces, and tries to align keywords so they 
> line up nicely, and I'd prefer doing it this way again.
> 
>  SELECT foo
>    FROM bar b
>    JOIN chair c USING (thekeycol)
>   WHERE ...
>     
> 
> 
> Regards,
> 
> Andreas
> 
> /***************************************
>  * check if given node is simple.
>  *  false  : not simple
>  *  true   : simple in the context of parent node's type
>  ***************************************/
> 
> static bool isSimpleNode(Node *node, NodeTag parentNodeType)
> {
>     if (!node)
>     return true;
> 
>     switch (nodeTag(node))
>     {
>     // single words: always simple
>     case T_Var:
>     case T_Const:
>     case T_Param:
> 
>     // function-like: name(..) or name[..]
>     case T_ArrayRef:
>     case T_FuncExpr:
>     case T_ArrayExpr:
>     case T_CoalesceExpr:
>     case T_NullIfExpr:
>     case T_Aggref:
> 
>         // CASE keywords act as parentheses
>     case T_CaseExpr:
>         return true;
> 
>         // appears simple since . has top precedence, unless parent is T_FieldSelect itself!
>     case T_FieldSelect:
>         return (parentNodeType == T_FieldSelect ? false : true);
> 
> 
>         // maybe simple, check args
>     case T_CoerceToDomain:
>         return isSimpleNode((Node*) ((CoerceToDomain*)node)->arg, T_CoerceToDomain);
>     case T_RelabelType:
>         return isSimpleNode((Node*) ((RelabelType*)node)->arg, T_RelabelType);
> 
> 
>     // depends on parent node type; needs further checking
>     case T_SubLink:
>     case T_NullTest:
>     case T_BooleanTest:
>     case T_OpExpr:
>     case T_DistinctExpr:
>         if (parentNodeType == T_BoolExpr)
>         return true;
>         // else check the same as for T_BoolExpr; no break here!
>     case T_BoolExpr:
>         switch (parentNodeType)
>         {
>         case T_ArrayRef:
>         case T_FuncExpr:
>         case T_ArrayExpr:
>         case T_CoalesceExpr:
>         case T_NullIfExpr:
>         case T_Aggref:
>         case T_CaseExpr:
>             return true;
>         default:
>             break;
>         }
>         return false;
> 
>         // these are not completely implemented; so far, they're simple
>     case T_SubPlan:
>     case T_CoerceToDomainValue:
>         return true;
> 
>     default:
>         break;
>     }
>     // those we don't know: in dubio complexo
>     return false;
> }
> 
> 
> 
> 
> 
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--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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