Port Bug Report: string concatenation operator association problem

============================================================================
                        POSTGRESQL BUG REPORT TEMPLATE
============================================================================


Your name        : Leo Kim
Your email address    : cocoja@sarang.net

Category        : runtime: back-end: SQL
Severity        : non-critical

Summary: string concatenation operator association problem

System Configuration
--------------------
  Operating System   : FreeBSD 2.2.8

  PostgreSQL version : 6.4

  Compiler used      : egcs 2.91.5

Hardware:
---------
Pentium II 300MHz, 128MB RAM

Versions of other tools:
------------------------


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

Problem Description:
--------------------
The string concatenation operator || doesn't have any associativity like + or -.
That is I can't use it as 'a' || 'b' || 'c' || 'd'.
I had to use parenthesis to get the result as (('a' || 'b') || 'c') || 'd'. I don't believe there should be a
particularreason to deffer || operator from other binary operator. Is this a bug? Or any intention for it? 

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

Test Case:
----------
create table x (data text);
insert into x values ('a'||'b'||'c'||'d'); <- not working
insert into x values (((('a'||'b')||'c')||'d')); <- working

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

Solution:
---------


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