Bruce,
The call in every c(simpleMap(tree)) is the activation of co-expression c
using the new(er) procedural syntax.
This may help http://rosettacode.org/wiki/Icon%2BUnicon/Intro#Co-expression_Flow
If you haven't already read it Steve's article in The Generator v2n2 Fun with
Co-expressions, part 2 explains this. There's links from RC's Unicon page and
the intro above.
Sorry, I don't have time for a longer explanation today.
Other RC tasks that use may provide examples
* http://rosettacode.org/wiki/Accumulator_factory
* http://rosettacode.org/wiki/Anonymous_recursion
* http://rosettacode.org/wiki/Closures/Variable_capture
* http://rosettacode.org/wiki/Function_composition
* and as I mentioned there is a Y-combinator page but it hasn't been
solved for Unicon
David
>________________________________
> From: Bruce & Breeanna Rennie <[email protected]>
>To: [email protected]
>Sent: Wednesday, December 21, 2011 6:24:47 AM
>Subject: Re: [Unicon-group] What is the idiomatic way to represent Lambda
>function in Icon/Unicon
>
>
>Thanks to both Steve and David for your respective pieces of information. I
>have been able to get a bit further into solving my problem which is
>translating the scheme interpreter for KERNEL (SINK) into Unicon/Icon. The
>reason for the translation is that SINK runs real slow.
>
>The next little problem, is finding a way to generate lots of
anonymous functions. I seem to recall seeing something like that
quite a few years ago.
>
>The following scheme code gives the idea of what I am translating.
The following is an extract from John Shutt's SINK file object.scm
>
>#; (define make-foo
>#; (lambda (bar quux)
>#; (let ((name (list #t)))
>#; (lambda (message)
>#; (case message
>#; ((type) 'foo)
>#; ((name) name)
>#; ((bar) bar)
>#; ((quux) quux))))))
>#;
>#; (define foo? (make-object-type-predicate 'foo))
>#;
>#; Sufficient accessors should be provided that clients never have
to know that
>#; encapsulated objects are dispatch procedures; for example, if
clients should
>#; have the ability to access the 'bar and 'quux attributes of a
foo,
>#;
>#; (define get-foo-bar (lambda (x) (x 'bar)))
>#; (define get-foo-quux (lambda (x) (x 'quux)))
>#;
>
>#;
>#; Determines whether all its arguments are objects.
>#;
>#(define object? procedure?)
>
>#;
>#; Given some number of symbol arguments, constructs a predicate
that takes
>#; an argument and determines whether it is an object whose type is
amongst
>#; the given symbols.
>#;
>#(define make-object-type-predicate
># (lambda types
># (lambda (object)
># (and (object? object)
># (pair? (member (object 'type) types))))))
>
>The make-object-type-predicate is used to generate anonymous
functions.
>
>I have just another look at what you have written Steve as below.
>
>
>procedure applyTests(tree, env, context) c := create repeat { operand :=
>(result@&source)[1] # allows function-style calls result := operand(env,
>context) # in case result is needed } @c # advances evaluation CE to
>'synchronization point', so next # value passed in gets assigned to operand.
>every c(simpleMap(tree)) # here, result is ignored
end
Would you mind explaining what is happening here. I think I have maybe
completely missed what is going on here. See if I have this right.
>
>result is a local variable with the initial value of &null
>result@&source simply returns control back to applyTests at the line @c
>
>What I stuck at is (and I thought I understood but sure now I don't)
the line
>
>every c(simpleMap(tree))
>
>What is actually happening here and how does this relate to the code
in the co-expression
>
>operand := (result@&source)[1]
>result := operand(env, context)
>
>I should be using Unicon much more but most of the work I do these
days is based on Microsoft Office products as these are the tools
that my clients run and so it is VBA mostly.
>
>I think I need to get more stuff done in other languages.
>
>Anyway back to the problem at hand. Would you mind explaining in
detail what is happening here, please.
>
>Clinton, would a extra section in your book be able to be written on
these kinds of subjects?
>
>regards
>
>Bruce Rennie
>getting slower as I age.
>
>
>
>
>
>------------------------------------------------------------------------------
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>new or port existing apps to sell to consumers worldwide. Explore the
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>_______________________________________________
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>
>
>------------------------------------------------------------------------------
Write once. Port to many.
Get the SDK and tools to simplify cross-platform app development. Create
new or port existing apps to sell to consumers worldwide. Explore the
Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join
http://p.sf.net/sfu/intel-appdev
_______________________________________________
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[email protected]
https://lists.sourceforge.net/lists/listinfo/unicon-group
