Print Page - Optimizing 'deep' setf

Title: Optimizing 'deep' setf
Post by: Tim Johnson on January 14, 2010, 05:50:43 PM

I have written a function that modifies a list

four "levels" deep, or to put it another way, has four dimensions.

My method uses multiple calls to 'setf. I would welcome any comments

or advices as to how to optimize this function - if possible.

The preconditions are this:

I have a list that has as members (level 1) that may be either

strings or lists. Any list at level 1 may have as members either

lists or strings. (level 2)

Any list at level 2 may be nested 2 more levels deep.

What follows is

List at level 2 before modification

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("form0"  ;; before
  ("type" "form") 
  ("attrs" (
    ("ID" "form0") 
    ("method" "POST") 
    ("name" "form0") 
    ("onsubmit" "return checkLoginForm(this);") 
    ("action" "[[action]]")))) ;; Value referenced by "action"

List at level 2 after modification

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("form0"   ;; after
  ("type" "form") 
  ("attrs" (
    ("ID" "form0") 
    ("method" "POST") 
    ("name" "form0") 
    ("onsubmit" "return checkLoginForm(this);") 
    ("action" "http://localhost/cgi-bin/test.lsp"))))  ;; value changed

Now here we have the function

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(define (set-form-action newaction (f 0))  ;; 'get-form sets 'current-formname
  (letn ((form-list(get-form f))           ;; level 1 referenced from 'DS by 'current-formname
         (form-tag (form-list 1))          ;; level 2
         (attrs(lookup "attrs" form-tag))  ;; level 3
         (action))
    (if (set 'action (assoc "action" attrs)) ;; level 4
      (begin
        (setf (action 1) newaction             ;; 'rewrite' at level 4
              (assoc "action" attrs) action))  ;; 'rewrite' at level 3
      (push (list "action" newaction) attrs -1))   ;; no pair. Add a pair
    (setf (form-tag 2 1) attrs                     ;; 'rewrite' at level 2
          (form-list 1) form-tag                   ;; 'rewrite' at level 1
          (assoc current-formname DS) form-list))) ;; 'rewrite' at level 0

Can this code be optimized or condensed? Insights from senior

newlispers will go a long ways to further educate me.

Thanks

tim

Title: Re: Optimizing 'deep' setf
Post by: hilti on January 14, 2010, 11:14:55 PM

Hi Tim,

I would probably try to simplify the code which POSTS the form. Normally You won't need a nested structure for posted data from HTML forms.

Download Dragonfly and take a look at the request.lsp

Here's what it works like: //http://www.rundragonfly.com/dragonfly_getpost

Cheers

Marc

Title: Re: Optimizing 'deep' setf
Post by: cormullion on January 15, 2010, 01:31:52 AM

How about:

Code Select Expand
(set-ref  '("action" ?) l '("action" "http://localhost/cgi-bin/test.lsp") match)

Title: Re: Optimizing 'deep' setf
Post by: Tim Johnson on January 15, 2010, 08:07:16 AM

~~Quote from: "hilti"~~Hi Tim,

I would probably try to simplify the code which POSTS the form. Normally You won't need a nested structure for posted data from HTML forms.

Download Dragonfly and take a look at the request.lsp

Here's what it works like: //http://www.rundragonfly.com/dragonfly_getpost

Cheers

Marc

Hi Marc, this has nothing to do with posting. It's about creating a form with data loaded

into it from a database.

thanks

tim

Title: Re: Optimizing 'deep' setf
Post by: Tim Johnson on January 15, 2010, 08:10:12 AM

~~Quote from: "cormullion"~~How about:

Code Select Expand (set-ref '("action" ?) l '("action" "http://localhost/cgi-bin/test.lsp") match)

Gotta try this. I will get back to you folks on it.

Thanks very much.

tim

Title: Re: Optimizing 'deep' setf
Post by: Tim Johnson on January 15, 2010, 05:32:32 PM

cormullion does it again. Here were have cut the LOC in half:

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(unless(set-ref '("action" ?) attrs (list "action" newaction) match)
  (push (list "action" newaction) attrs -1))

But this raises a couple of more questions. Obviously the functor argument

Code Select Expand
 match

does its job here, but I'm trying to use 'match as standalone

and not getting the results I want:

Code Select Expand

> (set 'attrs '(("ID" "form0") ("method" "POST") ("name" "form0")))
(("ID" "form0") ("method" "POST") ("name" "form0"))
> (match '("ID" ?) attrs)
nil

What am I doing wrong?

thanks

tim

Title: Re: Optimizing 'deep' setf
Post by: cormullion on January 16, 2010, 01:01:17 AM

I don't think you're reflecting the pattern of the target list precisely enough. This might work:

Code Select Expand
(match '(("ID" ?) *) attrs true)

Title: Re: Optimizing 'deep' setf
Post by: Tim Johnson on January 16, 2010, 08:37:50 AM

~~Quote from: "cormullion"~~I don't think you're reflecting the pattern of the target list precisely enough. This might work:

Code Select Expand (match '(("ID" ?) *) attrs true)

That's correct. Thanks.

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Forum => So, what can you actually DO with newLISP? => Topic started by: Tim Johnson on January 14, 2010, 05:50:43 PM