Re: [netrexx-pipelines] SPECs Stage Update

[J L. T. <jlt...@ma...>]

	Wow!  Now I can hardly wait for the next release!  Thank you so much.

Leslie

On 2023-01-04 13:10:24 Jeff Hennick wrote:
>   I have made a major update to the SPEC stage (and expect it is the last
> for it for a while).  It will be in the next release of NetRexx.  It is
> currently available from SourceForge.  Since it uses the "stageExit"
> method, it can only be compiled into the full NetRexxC.jar.
>
> CMS Pipelines has built into the SPEC stage its own programming language.
> It is Rexx-like-but-not-quite-Rexx.  For NetRexx Pipelines, I did not --
> and recommend we do not -- attempt to duplicate it.  What we have built in,
> and I have used instead, is the worlds best scripting language: NetRexx. 
> This gives all the power, but with a somewhat different syntax, of the CMS
> version.  I have incorporated this into the "Conversion" phase, with the
> key word NETREXX (or NR) and a delimitedString containing the NetRexx
> source.  In running, this code is encapsulated in a method.  The data
> selected in the Input phase is available as the variable data.  And
> whatever is returned is passed to the Output phase of the stage.  (As a
> convenience, if the last statement is not RETURN, the statement "return
> data" is automatically added.)  So all of these pipes work the same (giving
> cba): pipe "literal abc | spec 1-* NR /return data.reverse/ 1 | cons"
> pipe "literal abc | spec 1-* NR @rev = data.reverse; return rev@ 1 | cons"
> pipe "literal abc | spec 1-* NR %data = data.reverse% 1 | cons"
> CMS also has COUNTERs.  Here in NetRexx, COUNTER is a class property and
> can be used as a full fledged NetRexx indexed variable, for example
> counter[3] or counter['gold'].  Counters are persistent for the life of the
> stage and shared across all NR invocations within a SPEC stage.  (CMS has a
> limited number of counters available, and suggests specifying the number
> needed in the SPEC options.  NetRexx has no such limitations and the
> COUNTERS option is ignored.) This NetRexx code can also use Identified
> Fields, below, similarly to counters.  The syntax is field["a"], for
> example.  Like CMS, fields are identified by a single letter, case
> sensitive, so up to 52 are available. DANGER:  Since the full power of
> NetRexx is available, you can get yourself in trouble!  Also, this code is
> three levels deep, and error messages may point to the wrong thing, at the
> "wrong time."  Debugging can be a bear.  You have been warned.
>
> These new Field Identifiers are are specified by a letter and colon before
> an input range. (There may be no blank between the letter and colon, there
> may be a space between the identifier and the range specifier.) The letter
> is any of the 52 a-zA-Z, and is case sensitive.
>
> Another new feature may make the sometimes dense options string a little
> easier to read.  Groups of Id-Input-Convert-Output may now have a
> non-functional comma separating them.  (At least at this time, the comma
> must have a BLANK after it, and optionally before it and must be in the
> right place.)
>
> This update now fully supports multiple output streams as well as inputs. 
> The output range of "." has been added, it is of use with Identified Fields
> and NR.  It causes no output from that input range.  Also,in NetRexx
> Pipelines only, an input range of "." gives a data field of "".  This may
> be of use with the new NETREXX converter phase.
>
> There are confirmation tests for (I think) all of the relevant options in
> the examples/pipes directory.
>
> The documentation is now:
>
>  
> .
> .
> =========
> Jeff

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