Re: exponentiation of Duration's

2010-11-19 Thread Carl Mäsak
Darren (>>>), Carl (>>), Darren (>): >>> Specific units, even "seconds" should not be mentioned at all in the >>> definition of "Instant" or "Duration"; instead, any particular units or >>> calendars or whatever would just be a property of the composing class. >> >> No disrespect, but it was the ab

Re: exponentiation of Duration's

2010-11-18 Thread Darren Duncan
Carl Mäsak wrote: Darren (>): Specific units, even "seconds" should not be mentioned at all in the definition of "Instant" or "Duration"; instead, any particular units or calendars or whatever would just be a property of the composing class. No disrespect, but it was the abandonment of abstrac

Re: exponentiation of Duration's

2010-11-18 Thread Carl Mäsak
Darren (>): > Specific units, even "seconds" should not be mentioned at all in the > definition of "Instant" or "Duration"; instead, any particular units or > calendars or whatever would just be a property of the composing class. No disrespect, but it was the abandonment of abstracty stuff like th

Re: exponentiation of Duration's

2010-11-18 Thread Darren Duncan
To clarify, by "define particular methods" I mean that said 2 roles would require composing classes to define them, not to include the code themselves. -- Darren Duncan Darren Duncan wrote: I think that "Instant" and "Duration" should simply be declarational roles that don't have any implement

Re: exponentiation of Duration's

2010-11-18 Thread Darren Duncan
I think that "Instant" and "Duration" should simply be declarational roles that don't have any implementation code to compose. Composing "Instant" or "Duration" into a type simply says that the objects of that type represent a point on a timeline or an amount of time. Specific units, even "se

Re: exponentiation of Duration's

2010-11-18 Thread Dave Whipp
On 11/17/2010 10:08 PM, Martin D Kealey wrote: Dimensioned numbers as restrictive types are useful, for uncovering bugs, including sometimes latent ones in ported code. Duration is a fairly clear example of a dimensioned quantity, and I think we should think twice about abandoning its dimension

Re: exponentiation of Duration's

2010-11-18 Thread Martin D Kealey
On Wed, 17 Nov 2010, Richard Hainsworth wrote: > Once a number has been generated, viz., by obtaining a duration, that number > can be manipulated however necessary. The interpretation of the number is a > matter for the programmer, not the language designer. All true. However I'd argue that you

Re: exponentiation of Duration's

2010-11-17 Thread Jon Lang
Moritz Lenz wrote: > Am 17.11.2010 17:50, schrieb Jon Lang: >> More generally, I wonder if maybe we _should_ provide a tool to help > > I think this question can only be answered in a meaningful way if somebody > actually implements such a thing as a module (which should be entirely > possible in R

Re: exponentiation of Duration's

2010-11-17 Thread Moritz Lenz
Am 17.11.2010 17:50, schrieb Jon Lang: If I'm following this correctly, shouldn't we just say that Duration does Num? Num is a class (think floating point number). The role you're looking for is probably either Numeric or Real. If we say that Duration inherits from Rat or FatRat, it automatica

Re: exponentiation of Duration's

2010-11-17 Thread Jon Lang
If I'm following this correctly, shouldn't we just say that Duration does Num? That way, a Duration can be used exactly like a Num is (with units measured in seconds); but it could also have special capabilities above and beyond what a Num can do, if such capabilities are needed. More generally,

Re: exponentiation of Duration's

2010-11-17 Thread Moritz Lenz
Am 17.11.2010 15:20, schrieb Oha: On 11/17/2010 02:56 PM, Carl Mäsak wrote: Or, by Ockham, since Duration is now deprived of its only task -- making life harder for the programmer -- remove it altogether from the language and just put a number type in its place, representing number of seconds.

Re: exponentiation of Duration's

2010-11-17 Thread Steve Pitchford
On Wed, Nov 17, 2010 at 2:20 PM, Oha wrote: > > I could be wrong but this reminds me that a Duration could not be only based > in seconds, but also in other units (which may automagically be converted to > seconds) and also those seconds may be leap or not. > > Maybe the point is that really the p

Re: exponentiation of Duration's

2010-11-17 Thread Oha
On 11/17/2010 02:56 PM, Carl Mäsak wrote: Or, by Ockham, since Duration is now deprived of its only task -- making life harder for the programmer -- remove it altogether from the language and just put a number type in its place, representing number of seconds. I could be wrong but this remind

Re: exponentiation of Duration's

2010-11-17 Thread Mason Kramer
I still have uses for Durations. For instance, I want to dispatch a different .Stringy method to Durations than to Nums. It's convenient to me that the difference between two Instants has a different type than the difference between 1654321681.123 and 1654321021.65438. I just think Durations

Re: exponentiation of Duration's

2010-11-17 Thread Carl Mäsak
Mark (>): > I'm not convinced that the type system shouldn't be helping with > dimensional analysis, but at least it shouldn't hurt.  By all means, > let the programmer raise a Duration to a power - but the type of the > result should not also be Duration.  In the absence of automatic > dimension t

Re: exponentiation of Duration's

2010-11-17 Thread Mark J. Reed
I'm not convinced that the type system shouldn't be helping with dimensional analysis, but at least it shouldn't hurt. By all means, let the programmer raise a Duration to a power - but the type of the result should not also be Duration. In the absence of automatic dimension tracking, just return

Re: exponentiation of Duration's

2010-11-17 Thread Moritz Lenz
Am 17.11.2010 14:02, schrieb Oha: On 11/17/2010 01:46 PM, Moritz Lenz wrote: Just as a data point, in physics duration squared does exist. On the other hand, i can see why an Instant can't be used as a linear value: it does not have a clear origin (or zero value). That's correct, and the reas

Re: exponentiation of Duration's

2010-11-17 Thread Oha
On 11/17/2010 01:46 PM, Moritz Lenz wrote: Just as a data point, in physics duration squared does exist. On the other hand, i can see why an Instant can't be used as a linear value: it does not have a clear origin (or zero value). Therefore the multiplication of two Instant may results in diff

Re: exponentiation of Duration's

2010-11-17 Thread Moritz Lenz
Am 17.11.2010 12:55, schrieb Richard Hainsworth: On 11/17/10 14:03, Moritz Lenz wrote: Am 17.11.2010 10:31, schrieb Kris Shannon: $duration * $duration # WRONG, durations aren't geometric $duration * 2 # ok, a duration twice as long 2 * $duration # same What are your thoughts? I've summarize

Re: exponentiation of Duration's

2010-11-17 Thread Richard Hainsworth
On 11/17/10 14:03, Moritz Lenz wrote: Am 17.11.2010 10:31, schrieb Kris Shannon: $duration * $duration# WRONG, durations aren't geometric $duration * 2# ok, a duration twice as long 2 * $duration# same What are your thoughts? I've summarized my th

Re: exponentiation of Duration's

2010-11-17 Thread Moritz Lenz
Am 17.11.2010 10:31, schrieb Kris Shannon: A recent rakudo commit [1] is a quick fix for #78896 [2] to allow exponentiation of Duration's. And it did so with a real world use case in mind. I'm uneasy with allowing this and I think the spec probably meant not to but is badly

exponentiation of Duration's

2010-11-17 Thread Kris Shannon
A recent rakudo commit [1] is a quick fix for #78896 [2] to allow exponentiation of Duration's. I'm uneasy with allowing this and I think the spec probably meant not to but is badly worded [3]: Durations allow additive operations with other durations, and allow any numeric operat