Class: Data::Distance
- Inherits:
-
Units
- Object
- Units
- Data::Distance
- Defined in:
- lib/barometer/data/distance.rb
Overview
A simple Distance class
Think of this like the Integer class. Enhancement is that you can create a number (in a certain unit), then get that number back already converted to another unit.
All comparison operations will be done in metric
NOTE: this currently only supports the scale of
kilometers (km) and miles (m). There is currently
no way to scale to smaller units (eg km -> m -> mm)
Constant Summary collapse
- METRIC_UNITS =
"km"
- IMPERIAL_UNITS =
"m"
Instance Attribute Summary collapse
-
#kilometers ⇒ Object
Returns the value of attribute kilometers.
-
#miles ⇒ Object
Returns the value of attribute miles.
Class Method Summary collapse
-
.km_to_m(km) ⇒ Object
CONVERTERS.
- .m_to_km(m) ⇒ Object
Instance Method Summary collapse
-
#<=>(other) ⇒ Object
OPERATORS.
- #imperial_default=(value) ⇒ Object
-
#initialize(metric = true) ⇒ Distance
constructor
A new instance of Distance.
-
#km(as_integer = true) ⇒ Object
return the stored kilometers or convert from miles.
-
#km=(km) ⇒ Object
store kilometers.
-
#m(as_integer = true) ⇒ Object
return the stored miles or convert from kilometers.
-
#m=(m) ⇒ Object
store miles.
- #metric_default=(value) ⇒ Object
- #nil? ⇒ Boolean
-
#to_f(metric = nil) ⇒ Object
will just return the value (no units) with more precision.
-
#to_i(metric = nil) ⇒ Object
will just return the value (no units).
-
#to_s(metric = nil) ⇒ Object
will return the value with units.
-
#units(metric = nil) ⇒ Object
will just return the units (no value).
-
#update_kilometers(m) ⇒ Object
when we set miles, it is possible the a non-equivalent value of kilometers remains.
-
#update_miles(km) ⇒ Object
when we set kilometers, it is possible the a non-equivalent value of miles remains.
Constructor Details
#initialize(metric = true) ⇒ Distance
Returns a new instance of Distance.
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# File 'lib/barometer/data/distance.rb', line 22 def initialize(metric=true) @kilometers = nil @miles = nil super(metric) end |
Instance Attribute Details
#kilometers ⇒ Object
Returns the value of attribute kilometers.
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# File 'lib/barometer/data/distance.rb', line 20 def kilometers @kilometers end |
#miles ⇒ Object
Returns the value of attribute miles.
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# File 'lib/barometer/data/distance.rb', line 20 def miles @miles end |
Class Method Details
.km_to_m(km) ⇒ Object
CONVERTERS
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# File 'lib/barometer/data/distance.rb', line 35 def self.km_to_m(km) return nil unless km && (km.is_a?(Integer) || km.is_a?(Float)) km.to_f * 0.622 end |
.m_to_km(m) ⇒ Object
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# File 'lib/barometer/data/distance.rb', line 40 def self.m_to_km(m) return nil unless m && (m.is_a?(Integer) || m.is_a?(Float)) m.to_f * 1.609 end |
Instance Method Details
#<=>(other) ⇒ Object
OPERATORS
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# File 'lib/barometer/data/distance.rb', line 83 def <=>(other) self.km <=> other.km end |
#imperial_default=(value) ⇒ Object
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# File 'lib/barometer/data/distance.rb', line 29 def imperial_default=(value); self.m = value; end |
#km(as_integer = true) ⇒ Object
return the stored kilometers or convert from miles
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# File 'lib/barometer/data/distance.rb', line 67 def km(as_integer=true) km = (@kilometers || Data::Distance.m_to_km(@miles)) km ? (as_integer ? km.to_i : (100*km).round/100.0) : nil end |
#km=(km) ⇒ Object
store kilometers
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# File 'lib/barometer/data/distance.rb', line 51 def km=(km) return if !km || !(km.is_a?(Integer) || km.is_a?(Float)) @kilometers = km.to_f self.update_miles(km.to_f) end |
#m(as_integer = true) ⇒ Object
return the stored miles or convert from kilometers
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# File 'lib/barometer/data/distance.rb', line 74 def m(as_integer=true) m = (@miles || Data::Distance.km_to_m(@kilometers)) m ? (as_integer ? m.to_i : (100*m).round/100.0) : nil end |
#m=(m) ⇒ Object
store miles
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# File 'lib/barometer/data/distance.rb', line 59 def m=(m) return if !m || !(m.is_a?(Integer) || m.is_a?(Float)) @miles = m.to_f self.update_kilometers(m.to_f) end |
#metric_default=(value) ⇒ Object
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# File 'lib/barometer/data/distance.rb', line 28 def metric_default=(value); self.km = value; end |
#nil? ⇒ Boolean
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# File 'lib/barometer/data/distance.rb', line 136 def nil? (@kilometers || @miles) ? false : true end |
#to_f(metric = nil) ⇒ Object
will just return the value (no units) with more precision
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# File 'lib/barometer/data/distance.rb', line 99 def to_f(metric=nil) (metric || (metric.nil? && self.metric?)) ? self.km(false) : self.m(false) end |
#to_i(metric = nil) ⇒ Object
will just return the value (no units)
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# File 'lib/barometer/data/distance.rb', line 93 def to_i(metric=nil) (metric || (metric.nil? && self.metric?)) ? self.km : self.m end |
#to_s(metric = nil) ⇒ Object
will return the value with units
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# File 'lib/barometer/data/distance.rb', line 105 def to_s(metric=nil) (metric || (metric.nil? && self.metric?)) ? "#{self.km} #{METRIC_UNITS}" : "#{self.m} #{IMPERIAL_UNITS}" end |
#units(metric = nil) ⇒ Object
will just return the units (no value)
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# File 'lib/barometer/data/distance.rb', line 111 def units(metric=nil) (metric || (metric.nil? && self.metric?)) ? METRIC_UNITS : IMPERIAL_UNITS end |
#update_kilometers(m) ⇒ Object
when we set miles, it is possible the a non-equivalent value of kilometers remains. if so, clear it.
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# File 'lib/barometer/data/distance.rb', line 117 def update_kilometers(m) return unless @kilometers difference = Data::Distance.m_to_km(m.to_f) - @kilometers # only clear kilometers if the stored kilometers is off be more then 1 unit # then the conversion of miles @kilometers = nil unless difference.abs <= 1.0 end |
#update_miles(km) ⇒ Object
when we set kilometers, it is possible the a non-equivalent value of miles remains. if so, clear it.
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# File 'lib/barometer/data/distance.rb', line 128 def update_miles(km) return unless @miles difference = Data::Distance.km_to_m(km.to_f) - @miles # only clear miles if the stored miles is off be more then 1 unit # then the conversion of kilometers @miles = nil unless difference.abs <= 1.0 end |