Re: pgbench - allow backslash continuations in \set expressions

On Wed, Jan 11, 2017 at 5:39 PM, Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> wrote:
>
> Hello,
>
>>> The attached patch adds backslash-return (well newline really)
>>> continuations
>>> to all pgbench backslash-commands.
>>>
>>> The attached test uses continuations on all such commands (sleep set
>>> setshell and shell).
>>>
>>> I think that adding continuations to psql should be a distinct patch.
>
>
>> The patch does not apply on the latest head, I guess this requires
>> rebasing since yours is posted in December.
>
>
> Strange. Here is a new version and a test for all known backslash-commands
> in pgbench.
>
> sh> git br test master
> sh> git apply ~/pgbench-continuation-3.patch
> # ok
> sh> git diff
> # ok
> sh> cd src/bin/pgbench
> sh> make
> sh> ./pgbench -t 1 -f SQL/cont.sql
> starting vacuum...end.
> debug(script=0,command=1): int 0
> debug(script=0,command=2): int 1
> debug(script=0,command=4): int 2
> 3
> debug(script=0,command=8): int 4
> transaction type: SQL/cont.sql
>
>> Again, it is giving trailing whitespace errors (as I reported for the
>> earlier version), plus it does not apply with git apply,
>
>
> It does above with the attached version.

It still gives me whitespace errors with git apply,

/Users/edb/Downloads/pgbench-continuation-3.patch:31: trailing whitespace.
continuation \\{newline}
/Users/edb/Downloads/pgbench-continuation-3.patch:39: trailing whitespace.
{continuation} { /* ignore */ }
/Users/edb/Downloads/pgbench-continuation-3.patch:40: trailing whitespace.
/Users/edb/Downloads/pgbench-continuation-3.patch:48: trailing whitespace.
{continuation} { /* ignore */ }
/Users/edb/Downloads/pgbench-continuation-3.patch:49: trailing whitespace.

error: patch failed: doc/src/sgml/ref/pgbench.sgml:810
error: doc/src/sgml/ref/pgbench.sgml: patch does not apply
error: patch failed: src/bin/pgbench/exprscan.l:65
error: src/bin/pgbench/exprscan.l: patch does not apply

Looks like an editor issue, I used awk '{ sub("\r$", ""); print }'
patch1 > patch2 to clean it and it was applying then.

>> hopefully that would be fixed once rebased. Other than that, I observed
>> that if after backslash space is there, then the command fails.
>
>
> Yes, this is expected.
>
>> I think it should be something like if after backslash some spaces are
>> there, followed by end-of-line then it should ignore these spaces and read
>> next line, atleast with this new meaning of backslash.
>
>
> Hmmm. This is not the behavior of backslash continuation in bash or python,
> I do not think that this is desirable to have a different behavior.
>
Okay, seems sensible.
>> Otherwise, it should be mentioned in the docs that backslash should not be
>> followed by space.
>
>
> I'm not sure. Doc says that continuation is "backslash-return", it cannot be
> more explicit. If it must say what it is not, where should it stop?
>
> --
> Fabien.

Please post the clean version and I'll mark it as ready for committer then.

--
Regards,
Rafia Sabih
EnterpriseDB: http://www.enterprisedb.com/