Class: Unit::System
- Inherits:
-
Object
- Object
- Unit::System
- Defined in:
- lib/unit/system.rb
Instance Attribute Summary collapse
-
#factor ⇒ Object
readonly
Returns the value of attribute factor.
-
#factor_symbol ⇒ Object
readonly
Returns the value of attribute factor_symbol.
-
#factor_value ⇒ Object
readonly
Returns the value of attribute factor_value.
-
#name ⇒ Object
readonly
Returns the value of attribute name.
-
#unit ⇒ Object
readonly
Returns the value of attribute unit.
-
#unit_symbol ⇒ Object
readonly
Returns the value of attribute unit_symbol.
Instance Method Summary collapse
-
#initialize(name) {|_self| ... } ⇒ System
constructor
A new instance of System.
- #load(input) ⇒ Object
- #parse_unit(expr) ⇒ Object
- #validate_unit(units) ⇒ Object
Constructor Details
#initialize(name) {|_self| ... } ⇒ System
Returns a new instance of System.
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# File 'lib/unit/system.rb', line 8 def initialize(name) @name = name @unit = {} @unit_symbol = {} # one is internal trivial factor @factor = {:one => {:symbol => 'one', :value => 1} } @factor_symbol = {'one' => :one} @factor_value = {1 => :one} @loaded_systems = [] @loaded_filenames = [] yield(self) if block_given? end |
Instance Attribute Details
#factor ⇒ Object (readonly)
Returns the value of attribute factor.
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# File 'lib/unit/system.rb', line 6 def factor @factor end |
#factor_symbol ⇒ Object (readonly)
Returns the value of attribute factor_symbol.
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# File 'lib/unit/system.rb', line 6 def factor_symbol @factor_symbol end |
#factor_value ⇒ Object (readonly)
Returns the value of attribute factor_value.
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# File 'lib/unit/system.rb', line 6 def factor_value @factor_value end |
#name ⇒ Object (readonly)
Returns the value of attribute name.
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# File 'lib/unit/system.rb', line 6 def name @name end |
#unit ⇒ Object (readonly)
Returns the value of attribute unit.
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# File 'lib/unit/system.rb', line 6 def unit @unit end |
#unit_symbol ⇒ Object (readonly)
Returns the value of attribute unit_symbol.
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# File 'lib/unit/system.rb', line 6 def unit_symbol @unit_symbol end |
Instance Method Details
#load(input) ⇒ Object
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# File 'lib/unit/system.rb', line 24 def load(input) case input when Hash data = input when IO data = YAML.load(input.read) when String if File.exist?(input) return if @loaded_filenames.include?(input) data = YAML.load_file(input) @loaded_filenames << input else load(input.to_sym) return end when Symbol return if @loaded_systems.include?(input) data = YAML.load_file(File.join(File.dirname(__FILE__), 'systems', "#{input}.yml")) @loaded_systems << input end load_factors(data['factors']) if data['factors'] load_units(data['units']) if data['units'] @unit.each do |name, unit| defs = unit.delete(:defs) unit[:def] = parse_unit(defs) if defs validate_unit(unit[:def]) end true end |
#parse_unit(expr) ⇒ Object
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# File 'lib/unit/system.rb', line 67 def parse_unit(expr) stack, result, implicit_mul = [], [], false expr.to_s.scan(TOKENIZER).each do |tok| if tok == '(' stack << '(' implicit_mul = false elsif tok == ')' compute(result, stack.pop) while !stack.empty? && stack.last != '(' raise(SyntaxError, 'Unexpected token )') if stack.empty? stack.pop implicit_mul = true elsif OPERATOR.key?(tok) compute(result, stack.pop) while !stack.empty? && stack.last != '(' && OPERATOR[stack.last][1] >= OPERATOR[tok][1] stack << OPERATOR[tok][0] implicit_mul = false else val = case tok when REAL then [[:one, tok.to_f, 1]] when DEC then [[:one, tok.to_i, 1]] when SYMBOL then symbol_to_unit(tok) end stack << '*' if implicit_mul implicit_mul = true result << val end end compute(result, stack.pop) while !stack.empty? result.last end |
#validate_unit(units) ⇒ Object
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# File 'lib/unit/system.rb', line 57 def validate_unit(units) units.each do |factor, unit, exp| #raise TypeError, 'Factor must be symbol' if !(Symbol === factor) #raise TypeError, 'Unit must be symbol' if !(Numeric === unit || Symbol === unit) #raise TypeError, 'Exponent must be numeric' if !(Numeric === exp) raise TypeError, "Undefined factor #{factor}" if !@factor[factor] raise TypeError, "Undefined unit #{unit}" if !(Numeric === unit || @unit[unit]) end end |