Re: [TIP] Sorting by ValueList and synchronized sorting

[Ken Ray]

> It's very handy, but a cognitive hurdle for me at first.  I'd never seen
> anything like it before.
> 
> Anyone else have a mental hiccup when they first encountered this?

Absolutely! Which is why there's couple of tips about this at my site:

http://www.sonsothunder.com/devres/revolution/tips/scrp004.htm
http://www.sonsothunder.com/devres/revolution/tips/str001.htm

(for anyone who's interested...)

:-)

Ken Ray
Sons of Thunder Software, Inc.
Email: [EMAIL PROTECTED]
Web Site: http://www.sonsothunder.com/



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Re: [TIP] Sorting by ValueList and synchronized sorting

[Hugh Senior]

A good point, Peter. It would not affect the example as only 7 day-values 
are involved, but longer value lists would indeed be affected.


on mouseUp
 sort lines of fld 1 numeric by valueList(word 1 of each)
end mouseUp

function valueList what
 put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into tList
 return itemOffset(what,tList)
end valueList

/H

---
I believe I discovered that this custom sort function has to be
modified in one tiny way to work properly. Instead of

sort lines of fld 1 by valueList(word 1 of each)

you have to do

sort lines of fld 1 numeric by valueList(word 1 of each)

The valueList function returns a number, so the sort has to be
numeric. IIRC, this caused a problem for me until I figured it out. I
could be misremembering

Peter M. Brigham 


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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

J. Landman Gay wrote:
But wait, there's more! Some time ago when the list was discussing 
custom parallel sorts, Dick Kriesel offered this enhancement:


  split varB by comma
  sort items of varA by varB[itemOffset(each,varA)]

If Dick's still reading the list, he should stand up and take a bow.


Heap powerful medicine.

Dick does some intriguingly sophisticated scripting.  He's not one to 
shy from complex tasks, and comes up with some strikingly elegant 
solutions, like that one.


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Re: [TIP] Sorting by ValueList and synchronized sorting

[Peter Brigham]

I believe I discovered that this custom sort function has to be  
modified in one tiny way to work properly. Instead of


sort lines of fld 1 by valueList(word 1 of each)

you have to do

sort lines of fld 1 numeric by valueList(word 1 of each)

The valueList function returns a number, so the sort has to be  
numeric. IIRC, this caused a problem for me until I figured it out. I  
could be misremembering


Peter M. Brigham
[EMAIL PROTECTED]


On Jun 17, 2008, at 10:01 PM, [EMAIL PROTECTED]  
wrote:



Richard Gaskin wrote:
I've been looking at this for two days and I can't wrap my head  
around it.


My understanding of the sort command is that I can tell it to sort  
by a
particular chunk, and in which direction (ascending or  
descending), and

by what form of data (numeric or date or text).

Indeed, the only examples in the docs are:

   sort field "Output"
   sort items of myInfo by word 2 of each -- sort by word 2 of the  
line

   sort lines of field thisField descending numeric by item x of each

I've never before seen a sort where the sort specifier is a literal
value. :\

If I simplify the above to move the function result inline, it would
look like:

  sort lines of fld 1 by "Monday"

What exactly does that do, and how does it do it?
And where did you learn how do that?  I can't find anything in the  
docs

like that.


It's just a custom sort function. Rev evaluates the function before
sorting each line, so what it is actually sorting by is a number in  
this

case. "Each" evaluates to the first word of each line in this case,
which the function then re-evaluates as the position in the list of  
days
of the week. So when "each" is "monday" the sort number is 1. When  
it's

Tuesday, the sort number is 2, and so forth.


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Re: [TIP] Sorting by ValueList and synchronized sorting

[Hugh Senior]

This is very elegant. With a little more tweaking, you could use it to 
choose any of more than 2 values! Now in the Scripter's Scrapbook.


Thank you, Jacque.

/H


J. Landman Gay wrote:
function whichOne var,fld1,fld2  -- from a handler by Tony Root
-- Handles a case where you need to return one value if your key is
empty, another if not.

  return (item offset(char 1 of (var = empty),"tf") of quote & fld1
&","& fld2 & quote)
end whichOne

Paul says:

"There's a great scripter working at Digital Pictures named Tony Root,
who wrote a one-line boolean evaluator that I corrupted into a function.
This handles the case where you need to return one value if your key is
empty, another if not. For example, if the social security number field
(var) is empty, then return "Please fill in your social security number"
(fld1); otherwise, return "Now please fill in the form on the next
page." (fld2). The elegant part (which Tony wrote) is getting the offset
of char 1 of an expression that resolves to true or false, of "tf". Wish
I'd thought of that. "

You don't have to use it for just empty/not empty. With some
adjustments, you can use it to choose between any two values. 


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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

But wait, there's more! Some time ago when the list was discussing 
custom parallel sorts, Dick Kriesel offered this enhancement:


 split varB by comma
 sort items of varA by varB[itemOffset(each,varA)]

If Dick's still reading the list, he should stand up and take a bow.

--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Jerry J]

From: Richard Gaskin <[EMAIL PROTECTED]>

But I guess I'm stuck on the old (outdated?) notion that functions are
evaluated before their result is used in the calling command


The "AHA" moment for me was some time ago when Jacque shared the  
beautiful line to shuffle something:


sort  by random()

AHA!

Cheer,
Jerry Jensen

P.S. Randomness is next to Godliness...

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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

Richard Gaskin wrote:

In other languages that's called iff. 


Whoa, I didn't know there was a name for it. Makes sense, since Tony 
came to HyperCard from other languages. So he was probably translating.


Paul's/Tony's implementation is 
very clever, but I believe it benchmarks a bit faster (and is easier to 
read) when written as an if-else without the itemoffset and concatenation:


Yeah, I'm sure you're right.

For some reason that reminds me of my New York friend, who wouldn't 
signal her lane changes. When we asked her why, she said, "What, and 
give away my strategy?"


--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

J. Landman Gay wrote:

Richard Gaskin wrote: 
It's very handy, but a cognitive hurdle for me at first.  I'd never seen 
anything like it before.


You probably blocked it. :) 



Wow.  So many posts I've overlooked.  Must have had stuff in beta during 
those threads. :)


Glad I took the time today, thought.  You _can_ teach an old dog new 
tricks. :)



Speaking of mental gymnastics, here's my favorite. I use it a lot. I 
didn't write it, it was written by Tony Root from HyperPro back in the 
day, and turned into a function by Paul Foraker:


function whichOne var,fld1,fld2  -- from a handler by Tony Root
-- Handles a case where you need to return one value if your key is 
empty, another if not.


   return (item offset(char 1 of (var = empty),"tf") of quote & fld1 
&","& fld2 & quote)

end whichOne

Paul says:

"There's a great scripter working at Digital Pictures named Tony Root, 
who wrote a one-line boolean evaluator that I corrupted into a function. 
This handles the case where you need to return one value if your key is 
empty, another if not. For example, if the social security number field 
(var) is empty, then return "Please fill in your social security number" 
(fld1); otherwise, return "Now please fill in the form on the next 
page." (fld2). The elegant part (which Tony wrote) is getting the offset 
of char 1 of an expression that resolves to true or false, of "tf". Wish 
I'd thought of that. "


You don't have to use it for just empty/not empty. With some 
adjustments, you can use it to choose between any two values.


In other languages that's called iff.  Paul's/Tony's implementation is 
very clever, but I believe it benchmarks a bit faster (and is easier to 
read) when written as an if-else without the itemoffset and concatenation:


function whichOne pVal, pTrue, pFalse
   if pVal is empty then return pTrue
   else return pFalse
end whichOne


A more classic iff would evaluate any expression to true or false - this 
one should handle empties as false as well:


function iff pExp, pTrue, pFalse
  if pExp is true then return pTrue
  else return pFalse
end iff

--
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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

Richard Gaskin wrote:

It's very handy, but a cognitive hurdle for me at first.  I'd never seen 
anything like it before.


You probably blocked it. :)





Anyone else have a mental hiccup when they first encountered this?



All of us. The concept is really snarly, and requires some mental 
gymnastics. And even with the ones I've written myself, I still have to 
figure them out all over again each time I want to use them.


Speaking of mental gymnastics, here's my favorite. I use it a lot. I 
didn't write it, it was written by Tony Root from HyperPro back in the 
day, and turned into a function by Paul Foraker:


function whichOne var,fld1,fld2  -- from a handler by Tony Root
-- Handles a case where you need to return one value if your key is 
empty, another if not.


  return (item offset(char 1 of (var = empty),"tf") of quote & fld1 
&","& fld2 & quote)

end whichOne

Paul says:

"There's a great scripter working at Digital Pictures named Tony Root, 
who wrote a one-line boolean evaluator that I corrupted into a function. 
This handles the case where you need to return one value if your key is 
empty, another if not. For example, if the social security number field 
(var) is empty, then return "Please fill in your social security number" 
(fld1); otherwise, return "Now please fill in the form on the next 
page." (fld2). The elegant part (which Tony wrote) is getting the offset 
of char 1 of an expression that resolves to true or false, of "tf". Wish 
I'd thought of that. "


You don't have to use it for just empty/not empty. With some 
adjustments, you can use it to choose between any two values.


--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

J. Landman Gay wrote:


Richard Gaskin wrote:


1. Using a function for a sortKey expression introduces a "sometimes" 
rule in terms of understanding the order of expression evaluation in the 
engine, in which most of the time functions are evaluated first but in 
this case the function is applied repeatedly for each line of the sort 
container as the sort command is run.


Well, not really. It's more like a substitution for what the engine does 
anyway. When the engine sorts a container, it has to assign a position 
for each element being sorted. A custom sort function does the same 
thing; the engine will use the number returned by the function when 
arranging the elements.


The order of evaluation hasn't changed, and functions are still 
evaluated first. But when sorting, each element has to be evaluated 
individually.


Right.  That's what initially threw me.

As far as I can recall, this optional form of the sort command is the 
only way to call a function iteratively without using a repeat loop.


Are there others I've forgotten?

It's very handy, but a cognitive hurdle for me at first.  I'd never seen 
anything like it before.


Anyone else have a mental hiccup when they first encountered this?

--
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 Managing Editor, revJournal
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

Richard Gaskin wrote:

So this tells me two things:

1. Using a function for a sortKey expression introduces a "sometimes" 
rule in terms of understanding the order of expression evaluation in the 
engine, in which most of the time functions are evaluated first but in 
this case the function is applied repeatedly for each line of the sort 
container as the sort command is run.


2. Using a function as a sortKey expression evaluates the sort container 
  as though by effectively adding data to it, rather than anything 
necessarily in the data itself.


Both of these are very valuable insights.  Thanks to all who helped 
explain this.


Yes indeed, now I can see many areas where this can be useful, but it 
also leaves me with a question:


Given #1 above, how does this affect performance?  Unless there's 
something ultra-tricky going on (wouldn't be the first time the engine 
surprised me that way ), I would imagine that performance is affected 
at least linearly, in which the overhead of the function call is 
multiplied by the number of lines of the container to arrive at the 
additional performance hit relative to a non-custom sort.


Perhaps I'll do some benchmarking to verify this theory


FWIW, I ran some benchmarks and it turns out the theory seems to hold 
up, in which the time taken for a custom function sort is roughly the 
same as the time to call the function multiplied by the number of lines 
of the data being sorted, plus the time of the sort itself.


This isn't surprising given how it works, but may be helpful if an 
alternative algorithm for what you want to accomplish is available.


But given the grace of the syntax and the reasonably good performance of 
the engine overall, if you need to use it you'll likely be hard-pressed 
to come up with anything that does that which is faster.


For benchmarking fetishists, the code I tested is below.

--
 Richard Gaskin
 Fourth World Media Corporation
 ___
 [EMAIL PROTECTED]   http://www.FourthWorld.com


on mouseUp
  put 1000 into n -- number of iterations to test
  put fld 1 into tData -- data to sort (mine was 535 lines)
  put the number of lines of tData into tLineNum -- for use in results
  --
  -- 1: Test time to call function
  put the millisecs into t
  repeat n
get foo()
  end repeat
  put the millisecs - t into t1
  --
  -- 2: Test time to do straight sort
  put tData into tmp
  set the itemdel to tab
  put the millisecs into t
  repeat n
sort lines of tmp by item 2 of each
  end repeat
  put the millisecs - t into t2
  --
  -- 3: Time to do custom sort:
  put tData into tmp
  put the millisecs into t
  repeat n
sort lines of tmp by foo()
  end repeat
  put the millisecs - t into t3
  --
  -- Results:
  put "For "&n&" iterations - "&\
  cr&"Time to call foo: "&t1  &\
  cr&"Time to perform simple sort: "&t2 &\
  cr&"Time to perform foo sort: "& t3 &\
  cr&"(foo time * number of lines)+ simple sort time = "&\
(t1* tLineNum)+ t2
end mouseUp



-- I tested with two variants of foo, each taking different approaches
-- with very different performance times:

--- Serious time-waster:
function foo
  repeat 100
get random()
  end repeat
  return it
end foo

-- Just complex enough to be measurable at 1000 iterations:
function foo
  get random()
  add 44 to it
  subtract  from it
  put 1* it into it
  put it div 5 + 6 into it
  get it + it / 4
  get round(it) + 10 + 1 + 1
  return it
end foo

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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

Richard Gaskin wrote:


1. Using a function for a sortKey expression introduces a "sometimes" 
rule in terms of understanding the order of expression evaluation in the 
engine, in which most of the time functions are evaluated first but in 
this case the function is applied repeatedly for each line of the sort 
container as the sort command is run.


Well, not really. It's more like a substitution for what the engine does 
anyway. When the engine sorts a container, it has to assign a position 
for each element being sorted. A custom sort function does the same 
thing; the engine will use the number returned by the function when 
arranging the elements.


The order of evaluation hasn't changed, and functions are still 
evaluated first. But when sorting, each element has to be evaluated 
individually.





2. Using a function as a sortKey expression evaluates the sort container 
 as though by effectively adding data to it, rather than anything 
necessarily in the data itself.


I guess you could think of it that way, but the paradigm seems a little 
skewed to me. Sorting a container requires the engine to assign a 
position to each element. If a custom sort function assigns a position 
instead, the engine will use the number returned by the function. 
Internally the engine is actually still assigning positions, but because 
the function provides a straightforward numeric order, the engine 
doesn't have to figure out what the order is, it just uses the numbers.


I don't think I'm explaining this very well. ;)



Given #1 above, how does this affect performance?


In my experience, not much. I suppose with a long list you might see a 
difference though.


 Unless there's 
something ultra-tricky going on (wouldn't be the first time the engine 
surprised me that way ), I would imagine that performance is affected 
at least linearly, in which the overhead of the function call is 
multiplied by the number of lines of the container to arrive at the 
additional performance hit relative to a non-custom sort.


Perhaps I'll do some benchmarking to verify this theory



Let us know.

--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

Richard Gaskin wrote:

But I guess I'm stuck on the old (outdated?) notion that functions are 
evaluated before their result is used in the calling command,


It's still doing that. The function is evaluated first, before the sort 
assigns it a position. The difference here is that "each" is evaluated 
for each element that is being sorted; the function runs once per line.




I'm certain that you're not crazy,


You may be taking too much for granted here. :)

--
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HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

Mark Smith wrote the magic phrase that made this much clearer to me:

> It's like attaching a temporary value to each line and sorting
> by that.

The moment of "a ha!"  Thank you, Mark.  Jim Ault's detailed explanation 
was also helpful.


So this tells me two things:

1. Using a function for a sortKey expression introduces a "sometimes" 
rule in terms of understanding the order of expression evaluation in the 
engine, in which most of the time functions are evaluated first but in 
this case the function is applied repeatedly for each line of the sort 
container as the sort command is run.


2. Using a function as a sortKey expression evaluates the sort container 
 as though by effectively adding data to it, rather than anything 
necessarily in the data itself.


Both of these are very valuable insights.  Thanks to all who helped 
explain this.


Yes indeed, now I can see many areas where this can be useful, but it 
also leaves me with a question:


Given #1 above, how does this affect performance?  Unless there's 
something ultra-tricky going on (wouldn't be the first time the engine 
surprised me that way ), I would imagine that performance is affected 
at least linearly, in which the overhead of the function call is 
multiplied by the number of lines of the container to arrive at the 
additional performance hit relative to a non-custom sort.


Perhaps I'll do some benchmarking to verify this theory

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Re: [TIP] Sorting by ValueList and synchronized sorting

[Mark Smith]

On 17 Jun 2008, at 23:57, Richard Gaskin wrote:
But I guess I'm stuck on the old (outdated?) notion that functions  
are evaluated before their result is used in the calling command,  
which would mean the calling sort command is effectively using:


   sort lines of fld 1 by 1


Except that though we don't know exactly what the engine is doing,  
it's probably computing the value of the sort expression for each  
line and then doing the sort.


Best,

Mark
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

J. Landman Gay wrote:

> Richard Gaskin wrote:> on mouseUp
>>> on mouseUp
>>> sort lines of fld 1 by valueList(word 1 of each)
>>> end mouseUp
>>>
>>> function valueList what
>>>   put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday"
>>>  into tList
>>>   return itemOffset(what,tList)
>>> end valueList
>>
>> If I simplify the above to move the function result inline, it would
>> look like:
>>
>>   sort lines of fld 1 by "Monday"
>>
>> What exactly does that do, and how does it do it?
...
> It's just a custom sort function. Rev evaluates the function before
> sorting each line, so what it is actually sorting by is a number in
> this case. "Each" evaluates to the first word of each line in this
> case, which the function then re-evaluates as the position in the list
> of days of the week. So when "each" is "monday" the sort number is 1.
> When it's Tuesday, the sort number is 2, and so forth.

Yes, I was mistaken in thinking it returned "Monday"; it wasn't using 
"item itemoffset(", but merely "itemoffset(" so it was returning "1" 
rather than "Monday".  So far so good.


But I guess I'm stuck on the old (outdated?) notion that functions are 
evaluated before their result is used in the calling command, which 
would mean the calling sort command is effectively using:


   sort lines of fld 1 by 1

1 what?

My tired brain still isn't getting it. :\


> I've posted some other custom sorts before. Actually, I think I
> once posted a more generic variation on Brett's script:
>
> local lKeyData, lLineCounter
>
> on sortBy keyField -- parallel sorting of linked flds
>put fld keyField into lKeyData
>put "data1,data2,data3" into dataFields -- fill in your fld names
> here
>repeat with i = 1 to the number of items of dataFields
>  put 0 into lLineCounter
>  sort lines of fld (item i of dataFields) by key()
>end repeat
> end sortBy
>
> function key
>add 1 to lLineCounter
>return line lLineCounter of lKeyData
> end key
>
> Same idea as the weekdays script, only this one is even more unweildy.

Only to your nimble mind.  To my addled one its workings remain a mystery.

I'm certain that you're not crazy, and uncertain about myself in that 
regard, so I'm confident once I wrap my head around this it will be very 
useful


--
 Richard Gaskin
 Fourth World Media Corporation
 ___
 [EMAIL PROTECTED]   http://www.FourthWorld.com

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Re: [TIP] Sorting by ValueList and synchronized sorting

[Jim Ault]

On 6/17/08 2:49 PM, "Richard Gaskin" <[EMAIL PROTECTED]> wrote:

> I've never before seen a sort where the sort specifier is a literal
> value. :\

> What exactly does that do, and how does it do it?
> And where did you learn how do that?  I can't find anything in the docs
> like that. 

Jeanne DeVoto wrote about this feature a few years ago.
The entry in the Rev docs for 'sort' describes "SortKey" as an *expression*
that evaluates to a value for each line.

This means that the expression could be a function call that returns a
result.

The idea is that Rev will generate a value for each line of a container.
This could be a chunk expression, or the use of a function that you write.
This value can be anything a function can return.

The 'each' key word says that considering each line, pass a param that is
equal to some string, and then run the function.

In most cases, your function will use this param to produce the desired
result, but does *not have to use the passed value* (see the first example
below).

The result returned by the function becomes the the value (or sort key) that
is used to re-order the lines of the container.  After it is used, it is
deleted.  This sort key does not become part of the line in the container.

--
Three examples of generating a sort key


Make a new main stack
make one new field named "originalData"
put some data lines in to this field
paste the following script into the stack script
then Apply, 
then type "sortThis" into the message box, hit enter.

 start copy script  --
global gCurrLineCount

on sortThis
  get field "originalData"
  put 0 into gCurrLineCount
  sort lines of it descending numeric by numSortReverse(word 1 of each)
  put it into reverseSort
  get field "originalData"
  
  sort lines of it by numSortGrouping(word 2 of each)
  put it into birdsOfAFeatherSort
  
  get field "originalData"
  sort lines of it by distanceFromBeginning(word 1 of each)
  put it into distanceFromTopSort
  
  get reverseSort & cr & cr
  get it  & birdsOfAFeatherSort & cr & cr
  get it  & distanceFromTopSort
  
  put it into message box
end sortThis


function numSortReverse dummyVal
  -- we don't use the dummyVal in this case
  --  we don't care what the line contains
  add 1 to gCurrLineCount
  return (gCurrLineCount)
end numSortReverse


function numSortGrouping offsetStr
  -- birds of a feather sort
  put lineOffset(offsetStr, field "originalData") into position
  return position
end numSortGrouping

function distanceFromBeginning offsetStr
  put offset(offsetStr, field "originalData") into position
  return position
end distanceFromBeginning

-- end copy script 

Hope this helps,

Jim Ault
Las Vegas


On 6/17/08 2:49 PM, "Richard Gaskin" <[EMAIL PROTECTED]> wrote:

> Hugh Senior wrote:
>> Have you needed to sort lists by a value list or synchronize different
>> lists, but thought it not easily do-able in Rev? You may find the following
>> tips useful.
>> 
>> In a field, type some lines where the first word is a random day of the
>> week, then...
>> 
>> on mouseUp
>>   sort lines of fld 1 by valueList(word 1 of each)
>> end mouseUp
>> 
>> function valueList what
>>   put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into tList
>>   return itemOffset(what,tList)
>> end valueList
> 
> I've been looking at this for two days and I can't wrap my head around it.
> 
> My understanding of the sort command is that I can tell it to sort by a
> particular chunk, and in which direction (ascending or descending), and
> by what form of data (numeric or date or text).
> 
> Indeed, the only examples in the docs are:
> 
> sort field "Output"
> sort items of myInfo by word 2 of each -- sort by word 2 of the line
> sort lines of field thisField descending numeric by item x of each
> 
> I've never before seen a sort where the sort specifier is a literal
> value. :\
> 
> If I simplify the above to move the function result inline, it would
> look like:
> 
>sort lines of fld 1 by "Monday"
> 
> What exactly does that do, and how does it do it?
> And where did you learn how do that?  I can't find anything in the docs
> like that.
> 
> TIA -


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Re: [TIP] Sorting by ValueList and synchronized sorting

[Mark Smith]

Richard, if you look at the 'valueList' function, it returns a number  
ie. the offset of a weekday name into the list of weekday names. It's  
this value that is being used to sort the list. It's like attaching a  
temporary value to each line and sorting by that.


If there were more than 9 weekdays, this example would have needed to  
specify numeric.


This is why you can sort by random(someBigNumber) to randomize a list  
- each line effectively gets a random number, and is sorted by it.


Best,

Mark

On 17 Jun 2008, at 22:49, Richard Gaskin wrote:

Hugh Senior wrote:
Have you needed to sort lists by a value list or synchronize  
different lists, but thought it not easily do-able in Rev? You may  
find the following tips useful.
In a field, type some lines where the first word is a random day  
of the week, then...

on mouseUp
  sort lines of fld 1 by valueList(word 1 of each)
end mouseUp
function valueList what
  put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday"  
into tList

  return itemOffset(what,tList)
end valueList


I've been looking at this for two days and I can't wrap my head  
around it.


My understanding of the sort command is that I can tell it to sort  
by a particular chunk, and in which direction (ascending or  
descending), and by what form of data (numeric or date or text).


Indeed, the only examples in the docs are:

   sort field "Output"
   sort items of myInfo by word 2 of each -- sort by word 2 of the  
line

   sort lines of field thisField descending numeric by item x of each

I've never before seen a sort where the sort specifier is a literal  
value. :\


If I simplify the above to move the function result inline, it  
would look like:


  sort lines of fld 1 by "Monday"

What exactly does that do, and how does it do it?
And where did you learn how do that?  I can't find anything in the  
docs like that.


TIA -

--
 Richard Gaskin
 Managing Editor, revJournal
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Re: [TIP] Sorting by ValueList and synchronized sorting

[J. Landman Gay]

Richard Gaskin wrote:

Hugh Senior wrote:
Have you needed to sort lists by a value list or synchronize different 
lists, but thought it not easily do-able in Rev? You may find the 
following tips useful.


In a field, type some lines where the first word is a random day of 
the week, then...


on mouseUp
  sort lines of fld 1 by valueList(word 1 of each)
end mouseUp

function valueList what
  put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into 
tList

  return itemOffset(what,tList)
end valueList


I've been looking at this for two days and I can't wrap my head around it.

My understanding of the sort command is that I can tell it to sort by a 
particular chunk, and in which direction (ascending or descending), and 
by what form of data (numeric or date or text).


Indeed, the only examples in the docs are:

   sort field "Output"
   sort items of myInfo by word 2 of each -- sort by word 2 of the line
   sort lines of field thisField descending numeric by item x of each

I've never before seen a sort where the sort specifier is a literal 
value. :\


If I simplify the above to move the function result inline, it would 
look like:


  sort lines of fld 1 by "Monday"

What exactly does that do, and how does it do it?
And where did you learn how do that?  I can't find anything in the docs 
like that.


It's just a custom sort function. Rev evaluates the function before 
sorting each line, so what it is actually sorting by is a number in this 
case. "Each" evaluates to the first word of each line in this case, 
which the function then re-evaluates as the position in the list of days 
of the week. So when "each" is "monday" the sort number is 1. When it's 
Tuesday, the sort number is 2, and so forth. I've posted some other 
custom sorts before. Actually, I think I once posted a more generic 
variation on Brett's script:


local lKeyData, lLineCounter

on sortBy keyField -- parallel sorting of linked flds
  put fld keyField into lKeyData
  put "data1,data2,data3" into dataFields -- fill in your fld names here
  repeat with i = 1 to the number of items of dataFields
put 0 into lLineCounter
sort lines of fld (item i of dataFields) by key()
  end repeat
end sortBy

function key
  add 1 to lLineCounter
  return line lLineCounter of lKeyData
end key

Same idea as the weekdays script, only this one is even more unweildy.

--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software   | http://www.hyperactivesw.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Richard Gaskin]

Hugh Senior wrote:
Have you needed to sort lists by a value list or synchronize different 
lists, but thought it not easily do-able in Rev? You may find the following 
tips useful.


In a field, type some lines where the first word is a random day of the 
week, then...


on mouseUp
  sort lines of fld 1 by valueList(word 1 of each)
end mouseUp

function valueList what
  put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into tList
  return itemOffset(what,tList)
end valueList


I've been looking at this for two days and I can't wrap my head around it.

My understanding of the sort command is that I can tell it to sort by a 
particular chunk, and in which direction (ascending or descending), and 
by what form of data (numeric or date or text).


Indeed, the only examples in the docs are:

   sort field "Output"
   sort items of myInfo by word 2 of each -- sort by word 2 of the line
   sort lines of field thisField descending numeric by item x of each

I've never before seen a sort where the sort specifier is a literal 
value. :\


If I simplify the above to move the function result inline, it would 
look like:


  sort lines of fld 1 by "Monday"

What exactly does that do, and how does it do it?
And where did you learn how do that?  I can't find anything in the docs 
like that.


TIA -

--
 Richard Gaskin
 Managing Editor, revJournal
 ___
 Rev tips, tutorials and more: http://www.revJournal.com
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Re: [TIP] Sorting by ValueList and synchronized sorting

[Phil Davis]

Thanks Hugh! This is quite cool.
Phil Davis


Hugh Senior wrote:
Have you needed to sort lists by a value list or synchronize different 
lists, but thought it not easily do-able in Rev? You may find the 
following tips useful.


In a field, type some lines where the first word is a random day of 
the week, then...


on mouseUp
 sort lines of fld 1 by valueList(word 1 of each)
end mouseUp

function valueList what
 put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into 
tList

 return itemOffset(what,tList)
end valueList

Of couse you could also apply any valid chunking expression such as 
(word 2 to -1 of item 3 of each), apply the valueList sort to 
variables as well as fields, store multiple valueLists as re-usable 
custom properties, make the valueList conditional upon other factors 
and so on. The point is that the built-in sort keys can be extended to 
include your own preferential order.


Applying the same logic above to multiple fields (or indeed 
variables), the following implements parallel sorting of linked 
fields, keeping the lists synchronized (based on an old HyperCard 
script by Brett Sher)...


Create 3 fields called 'data1', 'data2' and 'data3'. Add lines of text 
into each field, for example a list of first names, last names, ages, 
then...


on mouseUp
 sortBy "data1" --| Sort by first name
end mouseUp

local lLineCounter,lKeyData
on sortBy keyField
 put fld keyField into lKeyData
 put "data1,data2,data3" into dataFields --| fill in your own field 
names here

 repeat with i = 1 to the number of items of dataFields
   put 0 into lLineCounter
   sort lines of fld (item i of dataFields) by key()
 end repeat
end sortBy

function key
  add 1 to lLineCounter
  return line lLineCounter of lKeyData
end key

Hope some of you may find the above helpful.


/H

Hugh Senior
www.ssBk.co.uk, Home of the Scripter's Scrapbook


--
Phil Davis

PDS Labs
Professional Software Development
http://pdslabs.net

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[TIP] Sorting by ValueList and synchronized sorting

[Hugh Senior]

Have you needed to sort lists by a value list or synchronize different 
lists, but thought it not easily do-able in Rev? You may find the following 
tips useful.


In a field, type some lines where the first word is a random day of the 
week, then...


on mouseUp
 sort lines of fld 1 by valueList(word 1 of each)
end mouseUp

function valueList what
 put "Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday" into tList
 return itemOffset(what,tList)
end valueList

Of couse you could also apply any valid chunking expression such as (word 2 
to -1 of item 3 of each), apply the valueList sort to variables as well as 
fields, store multiple valueLists as re-usable custom properties, make the 
valueList conditional upon other factors and so on. The point is that the 
built-in sort keys can be extended to include your own preferential order.


Applying the same logic above to multiple fields (or indeed variables), the 
following implements parallel sorting of linked fields, keeping the lists 
synchronized (based on an old HyperCard script by Brett Sher)...


Create 3 fields called 'data1', 'data2' and 'data3'. Add lines of text into 
each field, for example a list of first names, last names, ages, then...


on mouseUp
 sortBy "data1" --| Sort by first name
end mouseUp

local lLineCounter,lKeyData
on sortBy keyField
 put fld keyField into lKeyData
 put "data1,data2,data3" into dataFields --| fill in your own field names 
here

 repeat with i = 1 to the number of items of dataFields
   put 0 into lLineCounter
   sort lines of fld (item i of dataFields) by key()
 end repeat
end sortBy

function key
  add 1 to lLineCounter
  return line lLineCounter of lKeyData
end key

Hope some of you may find the above helpful.


/H

Hugh Senior
www.ssBk.co.uk, Home of the Scripter's Scrapbook 


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