[Swift-devel] Interesting observation when running Swift

[Mihael Hategan]

Swift doesn't monitor the file system.
Data driven doesn't mean that it does magic in the background. It means
that you have to express data dependencies in the code.

On Tue, 2007-04-10 at 11:47 -0500, Tiberiu Stef-Praun wrote:
> I have a workflow along these lines:
> 
> // this one generates outputsStage1[]
> stage1()
> // this one merges the stage1 outputs
> stage2(outputsStage1[])
> 
> note that it is not outputsStage1=stage1()
> 
> Since the outputsStage1 files were not generated yet, I expected that
> Karajan waited for them to be created before running stage2, but that
> was not the case: stage2 was executed when the workflow started (and
> it failed) and caused the workflow to fail.
> 
> I know how to fix the workflow, that is not the issue. The issue is
> that I expected the workflow to be data-driven, but it seems to be
> code driven. Explanation: it attempted to execute a section even if
> its input files were not available.
> 
> Correct me if I am wrong.
> Tibi
>