This module is an XIST namespace. It provides the processing instruction classes needed to create TOXIC functions and procedures via XIST. For more info about the TOXIC compiler see the module ``ll.toxicc``.


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class ``args``​(``ll.xist.xsc.ProcInst``):
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Specifies the arguments to be used by the generated function. For example:

   <?args
      key in integer,
      lang in varchar2
   ?>

for Oracle, or:

   <?args
      @key int,
      @lang varchar(10)
   ?>

for SQL Server. If ``args`` is used multiple times, the contents will be concatenated with a ``,`` inbetween.


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class ``vars``​(``ll.xist.xsc.ProcInst``):
==========================================

Specifies the local variables to be used by the function. For example:

   <?vars
      buffer varchar2(200) := 'foo';
      counter integer;
   ?>

for Oracle, or:

   <?vars
      declare @buffer varchar(200) := 'foo';
      declare @counter int;
   ?>

If ``vars`` is used multiple times, the contents will simple be concatenated. (Note that for SQL Server this could be done via a normal ``code`` PI too.)


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class ``code``​(``ll.xist.xsc.ProcInst``):
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A SQL code fragment that will be embedded literally in the generated function. For example:

   <?code select user into v_user from dual;?>

for Oracle, or:

   <?code set @user = user;?>

for SQL Server


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class ``expr``​(``ll.xist.xsc.ProcInst``):
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The data of an ``expr`` processing instruction must contain a SQL expression whose value will be embedded in the string returned by the generated function. This value will not be escaped in any way, so you can generate XML tags with ``expr`` PIs but you must make sure to generate the value in the encoding that the caller of the generated function expects.


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class ``proc``​(``ll.xist.xsc.ProcInst``):
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When this processing instruction is found in the source ``compile`` will not generate a function as a result, but a procedure. This procedure must have ``c_out`` as an "out" variable (of the appropriate type (see ``type``) where the output will be written to.


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class ``type``​(``ll.xist.xsc.ProcInst``):
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Can be used to specify the return type of the generated function/procedure. The default is ``clob`` for Oracle and ``varchar(max)`` for SQL Server.