OpenEuphoria

1. prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at c?wg?r.com> Apr 24, 2008
• 718 views
• Last edited Apr 25, 2008

Ok, another question now about the standard library.

Currently, two files have been added that are prefixed.... map.e and datetime.e.
Functions are like:

include map.e
map m
m = map_new()
m = map_put(m, "name", "John Doe")
puts(1, "Name: " & map_get(m, "name"))

include datetime.e
datetime dt
dt = datetime_now()
dt = datetime_new(2008, 10, 20, 11, 12, 13)
dt = datetime_add_days(30)
-- ...etc...

All function names in these two items thus far: map_new(), map_get(), map_put(),
map_remove(), map_size(), map_keys(), map_values() and datetime_new(),
datetime_compare(), datetime_from_date(), datetime_now(), datetime_dow(),
datetime_to_unix(), datetime_from_unix(), datetime_add_seconds(),
datetime_add_days(), datetime_diff_seconds(), datetime_diff_days(). Global
constants: DT_YEAR, DT_MONTH, DT_DAY, DT_HOUR, DT_MINUTE, DT_SECOND.

Should we omit the map_ and datetime_ and do things like:

include datetime.e as dt

dt:now()
dt:add_days(30)
dt:from_unix(1029382)

map:put(m, "name", "John")
map:get(m, "name")

One concern I have is both map and datetime have the "new" function. Also,
datetime has datetime_compare, which would become compare(). That does not matter
if you do include with a namespace but...

Thoughts?

--
Jeremy Cowgar
http://jeremy.cowgar.com

3. Re: prefixes and namespaces?

• Posted by Salix <salix at freemail??u> Apr 24, 2008
• 680 views
• Last edited Apr 25, 2008

Jeremy Cowgar wrote:

> One concern I have is both map and datetime have the "new" function. Also,
> datetime
> has datetime_compare, which would become compare(). That does not matter if
> you do include with a namespace but...
> 
> Thoughts?
> 

I vote for prefixes. I think the datetime_compare() example 
is great beacuse it shows how confusing it could be for a newbie.

I think somebody has already suggested to have "dt_" prefix instead 
of "datetime_" one. Please reconsider this idea...

Üdv: 

Salix

5. Re: prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at co?ga?.com> Apr 24, 2008
• 680 views
• Last edited Apr 25, 2008

Bernie Ryan wrote:
> 
> 
>      I have no idea what map.e is or what it is used for and
>       who said it is an important library ?

Bernie,

map is a dictionary. It's vital to many applications. If you doubt it's
usefulness, look at the archive at how many implementations there are and then
look at any other modern language and you will find map.

--
Jeremy Cowgar
http://jeremy.cowgar.com

7. Re: prefixes and namespaces?

• Posted by don cole <doncole at pacb?ll.n?t> Apr 24, 2008
• 687 views
• Last edited Apr 25, 2008

Jeremy Cowgar wrote:
> 
> Ok, another question now about the standard library.
> 
> Currently, two files have been added that are prefixed.... map.e and
> datetime.e.
> Functions are like:
> 
> }}}
<eucode>
> include map.e
> map m
> m = map_new()
> m = map_put(m, "name", "John Doe")
> puts(1, "Name: " & map_get(m, "name"))
> 
> include datetime.e
> datetime dt
> dt = datetime_now()
> dt = datetime_new(2008, 10, 20, 11, 12, 13)
> dt = datetime_add_days(30)
> -- ...etc...
> </eucode>
{{{

> 
> All function names in these two items thus far: map_new(), map_get(),
> map_put(),
> map_remove(), map_size(), map_keys(), map_values() and datetime_new(),
> datetime_compare(),
> datetime_from_date(), datetime_now(), datetime_dow(), datetime_to_unix(),
> datetime_from_unix(),
> datetime_add_seconds(), datetime_add_days(), datetime_diff_seconds(),
> datetime_diff_days().
> Global constants: DT_YEAR, DT_MONTH, DT_DAY, DT_HOUR, DT_MINUTE, DT_SECOND.
> 
> Should we omit the map_ and datetime_ and do things like:
> 
> }}}
<eucode>
> include datetime.e as dt
> 
> dt:now()
> dt:add_days(30)
> dt:from_unix(1029382)
> 
> map:put(m, "name", "John")
> map:get(m, "name")
> </eucode>
{{{

> 
> One concern I have is both map and datetime have the "new" function. Also,
> datetime
> has datetime_compare, which would become compare(). That does not matter if
> you do include with a namespace but...
> 
> Thoughts?
> 
> --
> Jeremy Cowgar
> <a href="http://jeremy.cowgar.com">http://jeremy.cowgar.com</a>

\Hello all,

as far as date and time I have written my own routines using the existing now.

I call it more_dates.e in the archives.

Such as getDayStr(),getDayDec().getStdTime(),getMilTime(), getESTime() etc...

I don't see why everybody can't do that for their own preferences. I see no need
to re write anything.


Don Cole

9. Re: prefixes and namespaces?

• Posted by Bernie Ryan <xotron at bluefro?.co?> Apr 24, 2008
• 697 views
• Last edited Apr 25, 2008

Jeremy Cowgar wrote:
> 
> Bernie Ryan wrote:
> > 
> > 
> >      I have no idea what map.e is or what it is used for and
> >       who said it is an important library ?
> 
> Bernie,
> 
> map is a dictionary. It's vital to many applications. If you doubt it's
> usefulness,
> look at the archive at how many implementations there are and then look at any
> other modern language and you will find map.
> 
> --

Jeremy:

   Where did map come from ?

   It is not in the archive.
   
   I don't see.

   Why aren't you using Associative Lists (Tables) by Jiri Babor

   who is a master at writing fast precise code.  



     	Associative Lists (Tables) 	17K	Jiri Babor




Bernie

My files in archive:
WMOTOR, XMOTOR, W32ENGIN, MIXEDLIB, EU_ENGIN, WIN32ERU, WIN32API 

Can be downloaded here:
http://www.rapideuphoria.com/cgi-bin/asearch.exu?dos=on&win=on&lnx=on&gen=on&keywords=bernie+ryan

11. Re: prefixes and namespaces?

• Posted by Mike777 <anon4321 at gmail??om> Apr 24, 2008
• 697 views
• Last edited Apr 25, 2008

Jeremy Cowgar wrote:
> 
> Bernie Ryan wrote:
> > 
> > 
> >      I have no idea what map.e is or what it is used for and
> >       who said it is an important library ?
> 
> Bernie,
> 
> map is a dictionary. It's vital to many applications. If you doubt it's
> usefulness,
> look at the archive at how many implementations there are and then look at any
> other modern language and you will find map.

What is the difference between a hash table and a map?

Mike

13. Re: prefixes and namespaces?

• Posted by Mike777 <anon4321 at gma??.com> Apr 24, 2008
• 668 views
• Last edited Apr 25, 2008

Jeremy Cowgar wrote:
> 
> Julio C. Galaret Viera wrote:
> > 
> > In my opinion it is not a good idea to prefix those functions.
> 
> Ok, noted as a vote no prefix.
>  
> > Neither is good to have so many functions like ...add_days, ..add_minutes,
> > weeks,
> > months and so on.
> > 
> > It would be enough to have an ADD function where you set the interval (year,
> > month, week, day...):
> > For example,
> > - add 30 days: ..._ADD(DAY, 30, mydate or mydatetime)
> > - add 1 week:  ..._ADD(WEEK, 1, mydate or mydatetime)
> 
> There are two methods for adding/subtracting. you saw them both add_seconds
> and add_days. They can be used to subtract by doing add_days(-10....).
> 
> The reason there are those two is due to simplicity. Adding seconds allows you
> to easily manipulate time. For instance, 3600*5 would add 5 hours. Adding days
> allows you to easily manipulate a day.
> 
> As for adding weeks, months, etc... That gets very difficult because what is
> a month, for instance? The average is 4.3 weeks, but that's an average. I
> think
> in most programs you don't wind up adding in intervals of weeks, months,
> etc...
> It's possible. But you could use, if you wish, add_days(7*4.3...) and add
> months,
> weeks, or whatever you wanted.
> 
> So, we did try to make things as minimal as possible by adding just two
> functions,
> add days and add seconds, as to work well with manipulating times and dates.

On this subject I can speak.  I work with addition and determination of dates
and ages frequently.  And it is all a crapshoot.  If you have access to Excel,
take a look at the types of dates they perceive can underly these determinations.
 Bankers rules are commonly used.  Completed periods are sometimes used. 
Rounding is sometimes used.  Rounding itself can be based on the interval in
question or a theoretical one.  That is, for some purposes, months are considered
to always have 30 days (daily compounding of interest between a certain number of
months, leading to the rule of 360).

In other words, I concur that having an add_months function is quite involved
(although certainly not impossible) and would require at least one additional
parameter to deal with the inconsistencies created by the months of our calendar
having different numbers of days.

Mike

15. Re: prefixes and namespaces?

• Posted by Mike777 <anon4321 at ?mail.com> Apr 25, 2008
• 693 views

Jeremy Cowgar wrote:
> 
> Mike777 wrote:
> > 
> > What is the difference between a hash table and a map?
> > 
> Practically? no difference. Both are key/value type devices.

Well, when I did my search on what to use, I came up with Hash Tables
(htables.zip) from jiri babor.  It is a year and a third newer than his
Associative Lists, referenced a few messages ago.

It has certainly worked for me.

Mike

17. Re: prefixes and namespaces?

• Posted by jacques deschênes <desja at g??betrotter.net> Apr 25, 2008
• 660 views

I vote for prefix,

jacques d.

Jeremy Cowgar wrote:
> 
> Ok, another question now about the standard library.
> 
> Currently, two files have been added that are prefixed.... map.e and
> datetime.e.
> Functions are like:
> 
> }}}
<eucode>
> include map.e
> map m
> m = map_new()
> m = map_put(m, "name", "John Doe")
> puts(1, "Name: " & map_get(m, "name"))
> 
> include datetime.e
> datetime dt
> dt = datetime_now()
> dt = datetime_new(2008, 10, 20, 11, 12, 13)
> dt = datetime_add_days(30)
> -- ...etc...
> </eucode>
{{{

> 
> All function names in these two items thus far: map_new(), map_get(),
> map_put(),
> map_remove(), map_size(), map_keys(), map_values() and datetime_new(),
> datetime_compare(),
> datetime_from_date(), datetime_now(), datetime_dow(), datetime_to_unix(),
> datetime_from_unix(),
> datetime_add_seconds(), datetime_add_days(), datetime_diff_seconds(),
> datetime_diff_days().
> Global constants: DT_YEAR, DT_MONTH, DT_DAY, DT_HOUR, DT_MINUTE, DT_SECOND.
> 
> Should we omit the map_ and datetime_ and do things like:
> 
> }}}
<eucode>
> include datetime.e as dt
> 
> dt:now()
> dt:add_days(30)
> dt:from_unix(1029382)
> 
> map:put(m, "name", "John")
> map:get(m, "name")
> </eucode>
{{{

> 
> One concern I have is both map and datetime have the "new" function. Also,
> datetime
> has datetime_compare, which would become compare(). That does not matter if
> you do include with a namespace but...
> 
> Thoughts?
> 
> --
> Jeremy Cowgar
> <a href="http://jeremy.cowgar.com">http://jeremy.cowgar.com</a>

19. Re: prefixes and namespaces?

• Posted by Mike777 <anon4321 at gma??.com> Apr 25, 2008
• 671 views

Jeremy Cowgar wrote:
> 
> Bernie Ryan wrote:
> > 
> >    Where did map come from ?
> 
> yuku

I think you got your ku's mixed up.  Aku.

Mike

21. Re: prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at ?owgar.?om> Apr 25, 2008
• 685 views

Mike777 wrote:
> 
> Jeremy Cowgar wrote:
> > 
> > Bernie Ryan wrote:
> > > 
> > >    Where did map come from ?
> > 
> > yuku
> 
> I think you got your ku's mixed up.  Aku.

I think they are the same person. You'll see posts here where he signs Aku and
also yuku. I guess he's better known as Aku.

--
Jeremy Cowgar
http://jeremy.cowgar.com

23. Re: prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at cowg?r.?om> Apr 25, 2008
• 697 views

Mike777 wrote:
> 
> How do I get access to that?  BTW, I think we were agreeing.
> 

Oh! I read your message wrong. I thought you were saying map in euphoria was 5
times slower. Re-read, my bad. Your saying my benchmark showed htable 5 times
slower than map, not map 5 times slower. Ok.

How do you get map or how do you get the benchmark?

The benchmark code for map is located in the message:

http://www.openeuphoria.org/EUforum/m19908.html

The benchmark for stable (faster than htable) can be found in that same message.
The benchmark for htable, as found in htable.zip, is slightly different than the
one for stable. It is:

include htables.e

integer n
sequence t
object v

n = 10000
t = new(1)

for i = 1 to n do
    t = make(t, sprintf("key%d", {i}), sprintf("value%d", {i}))
end for

for i = 1 to n do
    v = fetch(t, sprintf("key%d", {i}))
    if equal(v, sprintf("value%d", {i})) = 0 then
        puts(1, "Invalid find\n")
        abort(1)
    end if
end for

To get the new Euphoria, you need to use svn:

svn co http://rapideuphoria.svn.sourceforge.net/svnroot/rapideuphoria/trunk
euphoria-4.0

--
Jeremy Cowgar
http://jeremy.cowgar.com

25. Re: prefixes and namespaces?

• Posted by Matt Lewis <matthewwalkerlewis at gma?l.co?> Apr 25, 2008
• 666 views

Jeremy Cowgar wrote:
> 
> Should we omit the map_ and datetime_ and do things like:
> 
> }}}
<eucode>
> include datetime.e as dt
> 
> dt:now()
> dt:add_days(30)
> dt:from_unix(1029382)
> 
> map:put(m, "name", "John")
> map:get(m, "name")
> </eucode>
{{{


I think so.

> One concern I have is both map and datetime have the "new" function. Also,
> datetime
> has datetime_compare, which would become compare(). That does not matter if
> you do include with a namespace but...

Can someone please justify datetime_compare()?  It just seems to add 
overhead to what could be accomplished with the built-in compare().  We
definitely need to be careful when overriding a built-in.

Matt

27. Re: prefixes and namespaces?

• Posted by Matt Lewis <matthewwalkerlewis at gm??l.com> Apr 25, 2008
• 671 views

Jeremy Cowgar wrote:
> 
> Salix wrote:
> >  
> > I vote for prefixes. I think the datetime_compare() example 
> > is great beacuse it shows how confusing it could be for a newbie.
> 
> That's one big stumbling block to me about totally no prefix. I'd like to hear
> an solution that addresses compare() directly.

Since the format of a datetime is:
  {year, month, date, hour, minute, second}
...it already works with the built-in compare, so datetime_compare() is
redundant.  If it didn't, an alternative solution would be to either
make it so, or to call it something other than compare.  Better to change
one exception than an encumber an entire library.

Matt

29. Re: prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at c?wgar.?om> Apr 25, 2008
• 671 views

yuku wrote:
> 
> It is because the current implementation use that data structure. (I
> simplified
> it from the {{d,m,y},{h,n,s}} used by original datetime.e). But can we be 
> sure
> that it is fixed like that? 

I think Matt is right.
 
> One pitfall for users: they won't be able to use built-in date() as argument
> to compare().

I'm not so sure that matters much because we have the datetime type. Users
should only be comparing 2 datetime types.

I'm in favor of dropping the datetime_compare function.

--
Jeremy Cowgar
http://jeremy.cowgar.com

31. Re: prefixes and namespaces?

• Posted by yuku <yuku at ikit?k.co?> Apr 25, 2008
• 695 views

Jeremy Cowgar wrote:
> }}}
<eucode>
> dt = d:add(dt, 3 * HOURS)
> dt = d:add(dt, 3 * WEEKS)
> dt = d:add(dt, 7 * DAYS)
> dt = d:subtract(dt, 30 * DAYS)
> dt = d:subtract(dt, 12.5 * HOURS)
> </eucode>
{{{

> 
> Note, I did not add YEARS as it is not a fixed unit. To do that correctly we
> would need to add a function add_years, which accounts for leap year.


I don't think that using multiplication like this is a good solution. 
We will not be able to add MONTHS and YEARS. Why do we omit months and years
if we can write HOURS MINUTES DAYS and WEEKS ?

Year and Month addition is more tricky, I will take examples from mysql.

+-----------------------------------------+
| date_add('2008-4-25', interval 1 month) |
+-----------------------------------------+
| 2008-05-25                              |
+-----------------------------------------+

+-----------------------------------------+
| date_add('2008-5-25', interval 1 month) |
+-----------------------------------------+
| 2008-06-25                              |
+-----------------------------------------+
So "1 month" is not translated to 30 or 31 days but it directly 
modifies based on the original date.


+-----------------------------------------+
| date_add('2008-5-31', interval 1 month) |
+-----------------------------------------+
| 2008-06-30                              |
+-----------------------------------------+
If the result is an invalid date, it is adjusted.

+----------------------------------------+
| date_add('2008-2-29', interval 1 year) |
+----------------------------------------+
| 2009-02-28                             |
+----------------------------------------+
The same goes for year.

+-----------------------------------------+
| date_add('2008-2-29', interval -1 year) |
+-----------------------------------------+
| 2007-02-28                              |
+-----------------------------------------+
Subtraction has the same result.

+-----------------------------------------+
| date_add('2008-2-29',interval 1.5 hour) |
+-----------------------------------------+
| 2008-02-29 02:00:00                     |
+-----------------------------------------+
No fractions allowed. Really important! Because how can we define 0.5 months or
0.5 years etc. Will be very messy.

...

So in order to accomodate year and month add/sub, why don't we make it

dt = d:add(dt, 3, HOURS)
dt = d:add(dt, 3, WEEKS)
dt = d:add(dt, 7, DAYS)
dt = d:add(dt, -30, MONTHS)
dt = d:add(dt, -12, YEARS)

1. I think subtract is not necessary, just use minus.

2. No fractions allowed except for SECONDS.

If fractions were allowed, d:add(dt, 1/6, HOURS) may not be 
equal to d:add(dt, 10, MINUTES) because of the floating point error.

33. Re: prefixes and namespaces?

• Posted by Jeremy Cowgar <jeremy at c??gar.com> Apr 25, 2008
• 680 views

yuku wrote:
> 
> So in order to accomodate year and month add/sub, why don't we make it
> 
> }}}
<eucode>
> dt = d:add(dt, 3, HOURS)
> dt = d:add(dt, 3, WEEKS)
> dt = d:add(dt, 7, DAYS)
> dt = d:add(dt, -30, MONTHS)
> dt = d:add(dt, -12, YEARS)
> </eucode>
{{{

> 
> 1. I think subtract is not necessary, just use minus.

I think a minus function is cake to implement and makes coding a bit more
readable... for instance:

integer days
puts(1, "Enter how many days ago you got paid: ")
days = get_integer_from_user()

dt = d:add(dt, -(days), DAYS)

--
-- vs...
--

integer days
puts(1, "Enter how many days ago you got paid: ")
days = get_integer_from_user()

dt = d:subtract(dt, days, DAYS)

Sure it's easy to write -(days), but it does not read naturally, and the sub
function nearly be:

global function subtract(datetime d, atom qty, integer interval)
    return add(dt, -(qty), interval)
end function

So, why not?

--
Jeremy Cowgar
http://jeremy.cowgar.com

35. Re: prefixes and namespaces?

• Posted by Matt Lewis <matthewwalkerlewis at gmail??om> Apr 25, 2008
• 684 views

Jeremy Cowgar wrote:
> 
> yuku wrote:
> > 
> > }}}
<eucode>
> > dt = d:add(dt, 3, HOURS)
> > </eucode>
{{{

> > 
> > 1. I think subtract is not necessary, just use minus.
> 
> I think a minus function is cake to implement and makes coding a bit more
> readable...
> for instance:

I prefer to use (and read) just the add() function, but if others think
subtract is clearer...

Matt