Float <-> String - Locale aware?

Dan Rathbun

Now: how does one do this properly?

The PROPER Ruby way is to either override a method, or add a new method to the base class. That's why I love Ruby. It's the Dynamic feature of the language.

Why is it that @Last/Google can override base classes (and do it very poorly/error prone, etc.) and I with 30+ years experience am not supposed to be allowed to?

Why does noone say anything when Rick Wilson overrides or adds to base classes or Sketchup classes?

The SKX project is/was a means of proposing/testing such new methods or base class overrides.

Dan Rathbun

@thomthom said:

decimal_separator = 1.2.to_l.to_s.match(/\d(\D)\d/)[1]
This returns the decimal separator.

1.23.to_s.tr!('.', decimal_separator)
And this outputs a float in the user's locale.

No, it returns a String representation of a Float, using the user's locale system decimal separator.
But .tr/.tr! will change ALL occurances of '.', whereas sub/sub! change only the first occurance.

picky, picky

thomthom

@dan rathbun said:

But .tr/.tr! will change ALL occurances of '.', whereas sub

Does it matter?

thomthom

@dan rathbun said:

@thomthom said:

Now: how does one do this properly?

The PROPER Ruby way is to either override a method, or add a new method to the base class. That's why I love Ruby. It's the Dynamic feature of the language.

Why is it that @Last/Google can override base classes (and do it very poorly/error prone, etc.) and I with 30+ years experience am not supposed to be allowed to?

Why does noone say anything when Rick Wilson overrides or adds to base classes or Sketchup classes?

The SKX project is/was a means of proposing/testing such new methods or base class overrides.

Regardless of who does it, overriding base class method in the SU environment is a no-no. One can not know how it will affect other scripts - they could be relying on the original behaviour.
I would love to override existing methods, but that only works if you have the sole control of the environment. And in SU Ruby, you don't.

The reason I avoid adding new methods is that one never knows if someone else also adds a method of the same name that does something different. Same problem as before.
Now, one could go about and prefix with your initial as the conventions are for root modules. But then again, say you create a a plugin that adds a method to a base class. It turns out to have a bug.
You fix that.
You then make another plugin with that fix.

But the a user could have your new plugin and the old bugged version of your first and it loads last overriding the method. Now you're stuck with the bugged version in both your plugins - because you don't have control over the environment your plugin lives on.

Now, this latter case is more of a problem for yourself, so if one want to do so then fine. But I avoid it.
But overriding base methods are still a no no.

I've seen Rick add to base classes. I've not seen him override base methods though.

@dan rathbun said:

Why is it that @Last/Google can override base classes (and do it very poorly/error prone, etc.) and I with 30+ years experience am not supposed to be allowed to?

Because they deploy the platform. They are the source.
You, me, everyone else got to try to live along side inside that environment without causing conflicts for each others.

@dan rathbun said:

The SKX project is/was a means of proposing/testing such new methods or base class overrides.

Yes - we where even talking with people from Google Sketchup if they thought some of it could cause conflicts.
Personally that project ended up being down-prioritised for other projects.

thomthom

Found a nice method:
http://code.google.com/apis/sketchup/docs/ourdoc/sketchup.html#format_degrees

It formats any numeral into a string using the user's locale with the model precision.

Example, Norwegian locale and 1 digit precision:
Sketchup.format_degrees(500.555)
Returns the string: "~ 500,6"

Now, if only I could find a method for the other way around...

Jim

It's OK to extend only specific instances with with some instance methods, and without modifying the base class.

Something like...


module Translatable
    def translate(lang)
        "Hi"
    end
end

str = "Hello"
str.extend(Translatable)
str.translate("en")

Dan Rathbun

@jim said:

It's OK to extend only specific instances with with some instance methods, and without modifying the base class.

Called creating a singleton method.

Dan Rathbun

@thomthom said:

Now, if only I could find a method for the other way around...

I don't think I can test the other way as my locale setting uses period as decimal point.

If your model units are metric, and your OS locale decimal separator is comma, what happens when you try to use the base class (SU extended) method String.to_l ?

Ex:
length = "5,43".to_l
(1) what does length then appear as in the console ?
(2) what does it appear as in an inputbox control ?
(3) what does it appear as in a webdialog ?

What happens when:
length = "5.43".to_l

cjthompson

Why won't "12,2".to_l.to_f work?

Dan Rathbun

@thomthom said:

Found a nice method:
...[snip]...
Example, Norwegian locale and 1 digit precision:
Sketchup.format_degrees(500.555)
Returns the string: "~ 500,6"

What happens when:
Sketchup.format_degrees(500,555)
Wouldn't you be specifying decimals in euro-format?
When I try it there is a conflict; Ruby sees the comma as an argument delimiter, and pukes up an argument (2 for 1) exception.

Dan Rathbun

@cjthompson said:

Why won't "12,2".to_l.to_f work?

I can't test that; it raises an:
<ArgumentError: (eval):0:into_l': Cannot convert "12,2" to Length>` because I think of my US-en locale settings.
TT will need to test it, with his euro settings.

Of course, "12.2".to_l.to_f works just fine for me (and anyone in the US.)

Dan Rathbun

@dan rathbun said:

@cjthompson said:

Why won't "12,2".to_l.to_f work?

Of course, "12.2".to_l.to_f works just fine for me (and anyone in the US.)

I take that back.

I set Format=Decimal, Units=Millimeters, Precision=0.0000mm, and the value returned (in Inches,) is:
"12.2".to_l.to_f >> 0.480314960629921
which is a precision to 15 decimal places. [FYI: 12.7mm is considered 0.5 inches. You often see 50 caliber weapons expressed as 12.7mm]

thomthom

@dan rathbun said:

(1) what does length then appear as in the console ?

length = "5,43".to_l
0.213779527559055

Because I use metric mm template it also converts the float into inches.

@dan rathbun said:

(2) what does it appear as in an inputbox control ?

2010-05-17 21h23_12.png
Because .to_s is called upon the Length object.

@dan rathbun said:

(3) what does it appear as in a webdialog ?

You'd have to convert it to a string to pass it to a webdialog, so the result would be the same as above.

thomthom

@dan rathbun said:

What happens when:
length = "5.43".to_l

length = "5.43".to_l Error: #<ArgumentError: (eval):894:into_l': Cannot convert "5.43" to Length>
(eval):894`

thomthom

@cjthompson said:

Why won't "12,2".to_l.to_f work?

"12,2".to_l.to_f 0.480314960629921

It doesn't work because SU does unit conversion at the same time.

Dan Rathbun

Back to the original question, then:

@thomthom said:

Is there any methods that do these conversions that are locale aware?

Are the Sketchup method extensions to the base classes, locale aware and suit your needs ??
String.to_l
Numeric.to_l

thomthom

@dan rathbun said:

Back to the original question, then:

@thomthom said:

Is there any methods that do these conversions that are locale aware?

Are the Sketchup method extensions to the base classes, locale aware and suit your needs ??
String.to_l
Numeric.to_l

.to_l and Length.to_s is locale aware. But, it does not suit my needs. I'm trying to convert between String and Float, not between String and Length.

As mentioned before:
Sketchup.format_degrees works for Float -> String
It even has the extra benefit of adhering to the model unit's precision.

But for String -> Float (where the string is formatted in the user's locale, which might include decimal separator other than a period) I only have this dirty hack:


  # Some locale settings uses the comma as decimal separator. .to_f does not
  # account for this, so all commas must be coverted to periods.
  def self.string_to_float(string)
    # Dirty hack to get the current locale's decimal separator, which is then
    # replaced in the string to a period which is what the .to_f method expects.
    @decimal_separator ||= 1.2.to_l.to_s.match(/\d(\D)\d/)[1]
    string.sub(@decimal_separator, '.').to_f
  end

Dan Rathbun

@thomthom said:

.to_l and Length.to_s is locale aware. But, it does not suit my needs. I'm trying to convert between String and Float, ... I only have this dirty hack:

you could subclass class String, and not need the parameter, ie:

class FloatString < String
  # override to_f method (or name it .to_loc_f )
  def self.to_f
    # insert your hack
  end
end # class

Use:
a = FloatString.new( someString.dup ) puts a.to_f puts a.class >> SomeModule::FloatString

thomthom

Well, how I wrap the code is one thing. But atm I'm more concerned about how I get the locale data.

It just occurred to me that might not be a good choice if one does not want the float to be truncated to the model's degree precision...

Dan Rathbun

We can see if the user is using metric, via:


module SU_UNIT
#
def length_name( arg='nameString' )
  #
  model = Sketchup.active_model 
  manager = model.options 
  unitopts = manager['UnitsOptions'] 
  #
  # allow the ordinal in the set to be returned if arg
  # is any class other than String (or a String subclass.)
  return unitopts['LengthUnit'] unless arg.kind_of?(String)
  #
  # arg was a String, so return LengthUnit stringname
  unit=''
  #
  if unitopts['LengthFormat']==0 # Decimal
    unitSet=['Inches','Feet','Millimeters','Centimeters','Meters']
    unit=unitSet[ unitopts['LengthUnit'] ]
  elsif unitopts['LengthFormat']==2 # Engineering
    unit='Feet'
  else # 1==Architectural, 3==Fractional
    unit='Inches'
  end # if
  #
  return unit
  #
end # method
#
end # module

%(#4000BF)[EDITED: wrapped in module and method blocks.
EDIT2: replaced case statement with array subscript call.
EDIT3: corrected ordinal values for LengthFormat (they do NOT appear in dropdown control in their true order!)
EDIT4: simplfied ordinal test; renamed method]

Float &lt;-&gt; String - Locale aware?

Float <-> String - Locale aware?