[Newbies] Re: How to doubble sort a collection

Chris Cunningham cunningham.cb at gmail.com
Wed Feb 4 17:20:16 UTC 2015


| and & make sure that each expression between them is executed - so it
will do each of:
   a date  > b date
and
   a date = b date
and
   a date > temps > b date temps

This matters if one of these is significantly slower than the others - it
will run it even it it doesn't need too.  Also if any side-effects are in
one of these expressions, this will make that side effect happen (there
aren't any in these, though).

and: and or: stop executing as soon as one of them is satisfied
sufficiently - so if a date > b date then it will immediately return true
without bothering with the rest of the expressions.
ifTrue:ifFalse: is similar - except you will evaluate the condition
expression AND one of the following expressions.

Often this doesn't matter one way or another - but when it does, it matters
a lot.

-cbc

On Wed, Feb 4, 2015 at 9:00 AM, Paul DeBruicker <pdebruic at gmail.com> wrote:

> Does using the | or & notation have any advantages over and: or or:  or
> ifTrue:ifFalse ?
>
>
> I always write expressions like the one you've written like:
>
> a date = b date
>    ifTrue:[a temps > b temps]
>    ifFalse:[a date > b date]
>
>
>
>
>
>
>
> Louis LaBrunda wrote
> > Hi Raymond,
> >
> > Try:
> >
> > ^notes sorted:[:a :b | (a date  > b date) | ((a date = b date) & (a date
> > temps > b date temps))].
> >
> > Lou
> >
> > On Wed, 04 Feb 2015 10:34:48 -0500, Raymond Asselin &lt;
>
> > jgr.asselin@
>
> > &gt;
> > wrote:
> >
> >>I have this kind of sorting on anOrderedCollection
> >>
> >>BlocNotes >>sortedNotes
> >>      ^notes sorted:[:a :b | a date  > b date]
> >>
> >>This sort my notes on date but I want them sort by date AND inside a date
> by hours and I don't khow how to do this.
> >>
> >>Some insights?
> >>
> >>aNote = 'med com date temps' instancesVariables what I call hours = temps
> witch is a number like 2123 for 21h23
> >>
> >>Some insights?
> > -----------------------------------------------------------
> > Louis LaBrunda
> > Keystone Software Corp.
> > SkypeMe callto://PhotonDemon
> > mailto:
>
> > Lou@
>
> >  http://www.Keystone-Software.com
> >
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>
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>
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>
>
>
>
>
> --
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> http://forum.world.st/How-to-doubble-sort-a-collection-tp4803657p4803671.html
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