[Swift-devel] Re: Swift Error!

[andrewj at uchicago.edu]

Mike,

  Thanks for the insight.  You are right.  I do need to attack
this piece-wise. I guess I was hoping to get lucky! I think it
is just the time constraint that is scarring me.  

Here goes it!

Thanks,
Andrew

>
>Andrew, due to Swift's highly parallel nature, debugging is
stil tricky.
>
>Ben and Mihael may have other suggestions, but I used the
debug function 
>  (coded as "myapp") in the example I sent you, to print various 
>variable values and to confirm that various functions were
entered and 
>exited.
>
>Ive got a lot of notes to write up (and userguid text to
suggest) 
>related to this, but in the meantime we need to give you a clear 
>understanding of how variables and expression evaluation
works in swift.
>
>In a nutshell:
>
>- every statement in a function is evaluated in
data-dependency order, 
>not in source-code order
>- variable instances can only be set once
>- expressions, including function calls, that consume values
wait until 
>the value is set
>- references to arrays as objects (ie by using one n a
foreach) block 
>until the array is set ("closed")
>- arrays are closed only when they are returned as the result
of a 
>procedure (note: not "array members" = the entire array)
>- print() does not currently wait for its arguments to close
(it will 
>soon: this is a deficiency)
>
>(All - please correct/extend this as needed. I will try to
write text 
>and examples of each of these points for the
userguide/tutorials but 
>please dont wait for me if you get the urge).
>
>Until you get the hang of this "data flow" model, writing
even simple 
>code can be tricky.
>
>Whats worse is that we dont yet have the ability to a)
include line 
>numbers in errors once you are out of the swift parser) and
b) its hard 
>to tell what you are hanging on when the whole script hangs.
>
>Thats why I urged you, and urge you again, Andrew, to start
testing the 
>program in small pieces, from the inside working outwards, so
that you 
>are building on known working code.
>
>This gets quite easy once you develop a solid mental model of
how swift 
>behaves, but getting there takes a few days of
experimentation (at least 
>it did for me, and Im about 75% there ;)
>
>I'll try to help you tomorrow, but others may be able to spot
some 
>problems in your source code.
>
>- Mike
>
>
>On 10/10/07 12:17 PM, andrewj at uchicago.edu wrote:
>> On that note, is there anyway to grab more information in real
>> time as to what is going on with swift?
>> 
>> de at mcs.anl.gov>, swiftdevel <swift-devel at ci.uchicago.edu>
>>> none of those messgaes are errors in themselves - they're
>> debugging 
>>> messages about what is going on inside.
>>>
>>> Do you mean to report that it then hangs 'forever'?
>>>
>>> On Wed, 10 Oct 2007, andrewj at uchicago.edu wrote:
>>>
>>>> Hello all,
>>>>
>>>>   I am getting the following to happen when I try to run
swift:
>>>>
>>>> [andrewj at terminable Swifty]$ swift -debug
10-10-07-CADWF.swift
>>>> 10-10-07-CADWF.swift: source file is new. Recompiling.
>>>> Validation of XML intermediate file was successful
>>>> Using sites file:
>>>> /home/andrewj/CADGrid/Swifty/vdsk-0.3/bin/../etc/sites.xml
>>>> Using tc.data:
>>>> /home/andrewj/CADGrid/Swifty/vdsk-0.3/bin/../etc/tc.data
>>>> Swift v0.3 r1319 (modified locally)
>>>>
>>>> Swift v0.3 r1319 (modified locally)
>>>>
>>>> RunID: 20071010-1204-pvgabtv1
>>>> RunID: 20071010-1204-pvgabtv1
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=malFMatrix
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=malFMatrix
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=malFMatrix
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=malFMatrix
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=feature
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=feature
>>>> Waiting for org.griphyn.vdl.mapping.RootDataNode with no
value
>>>> at dataset=feature
>>>>
>>>> You guys are free to look at the swift code located in
>>>> /home/andrewj/CADGrid/Swifty/ mounted on the ci disk.
>>>>
>>>> Suggestions?
>>>>
>>>> Thanks,
>>>> Andrew
>>>>
>>>>
>> 
>>