[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[O] [babel] Noweb expansion, not noweb evaluation...
From: |
Sebastien Vauban |
Subject: |
[O] [babel] Noweb expansion, not noweb evaluation... |
Date: |
Mon, 31 Oct 2011 17:22:13 +0100 |
User-agent: |
Gnus/5.110018 (No Gnus v0.18) Emacs/24.0.50 (windows-nt) |
Hi Eric,
* Overview
In order to be able to create a big code from small chunks, I need to compose
with the *expanded* view of a block, instead of its *evaluated* result.
I don't see how to do that while keeping the small block *executable*.
* Use case
A use case could explain the need in a much clearer manner.
I have a SQL block that duplicates a row:
#+srcname: insert-duplicate-row-with-ID
#+begin_src sql :var table="order" :var column="ID" :var
source_value="'73-0007'" :var target_value="'73-0008'"
INSERT INTO $table
...
#+end_src
This block is executable, that is I can call it on the fly to make what I
mean. This is good.
Now, I wanna make use of that general "function" in a long stored procedure,
customized to duplicate a row in a large set of tables. Something like this:
#+begin_src sql :noweb yes
CREATE PROCEDURE clone_row_with_ID
@source_value varchar(16),
@target_value varchar(16)
AS
<<insert-duplicate-row-with-ID("table1", "column", "@source_value",
"@target_value")>>
<<insert-duplicate-row-with-ID("table2", "column", "@source_value",
"@target_value")>>
...
<<insert-duplicate-row-with-ID("tableN", "column", "@source_value",
"@target_value")>>
GO
#+end_src
But this does not work, as Babel replaces the Noweb call with the results of
its evaluation, not with the results of its *expansion*.
Is there a way to get it working?
* Workaround
A very ugly workaround which I see is that:
- the reference block prints out SQL code: for example, an AWK code printing
SQL statement.
- the general block calls Noweb, and receives the output of AWK's execution,
hence expanded SQL code.
But, then, the reference block is not executable anymore. Not really a
workaround, then...
Best regards,
Seb
--
Sebastien Vauban
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [O] [babel] Noweb expansion, not noweb evaluation...,
Sebastien Vauban <=