Float <-> String - Locale aware?

[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 ?

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]

[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 string in the user's locale.

Hacky hacky hacky...

Now: how does one do this properly?

lets try sprintf (the standard **s**tring print **f**ormatted method,) which returns a formatted String.

On your machine how does the following work?
` decplaces=6 # some integer arg or expression
sprintf("%##{decplaces}f",51.1230)

the first '#' is a format flag

the second '#' is part of #{decplaces}`

[thomthom]

Tried that. It's locale unaware.

The only stuff I get on Ruby and locale relates to Ruby on Rails.

[eneroth3]

This method only works when format is set to decimal (or engineering which is also decimal) in the model info. If fractional or architectural are used '1.2.to_l.to_s" returns '~ 1 1/4"' without any decimal separator.