Class: Dentaku::Calculator

Inherits:
Object
  • Object
show all
Defined in:
lib/dentaku/calculator.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ast_cache = {}) ⇒ Calculator

Returns a new instance of Calculator.



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# File 'lib/dentaku/calculator.rb', line 11

def initialize(ast_cache={})
  clear
  @tokenizer = Tokenizer.new
  @ast_cache = ast_cache
  @disable_ast_cache = false
end

Instance Attribute Details

#memory ⇒ Object (readonly)

Returns the value of attribute memory.



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# File 'lib/dentaku/calculator.rb', line 9

def memory
  @memory
end

#result ⇒ Object (readonly)

Returns the value of attribute result.



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# File 'lib/dentaku/calculator.rb', line 9

def result
  @result
end

#tokenizer ⇒ Object (readonly)

Returns the value of attribute tokenizer.



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# File 'lib/dentaku/calculator.rb', line 9

def tokenizer
  @tokenizer
end

Instance Method Details

#add_function(name, type, body) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 18

def add_function(name, type, body)
  Dentaku::AST::Function.register(name, type, body)
  self
end

#add_functions(fns) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 23

def add_functions(fns)
  fns.each { |(name, type, body)| add_function(name, type, body) }
  self
end

#ast(expression) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 61

def ast(expression)
  @ast_cache.fetch(expression) {
    Parser.new(tokenizer.tokenize(expression)).parse.tap do |node|
      @ast_cache[expression] = node if cache_ast?
    end
  }
end

#cache_ast? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dentaku/calculator.rb', line 120

def cache_ast?
  Dentaku.cache_ast? && !@disable_ast_cache
end

#clear ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 112

def clear
  @memory = {}
end

#clear_cache(pattern = :all) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 69

def clear_cache(pattern=:all)
  case pattern
  when :all
    @ast_cache = {}
  when String
    @ast_cache.delete(pattern)
  when Regexp
    @ast_cache.delete_if { |k,_| k =~ pattern }
  else
    fail Dentaku::ArgumentError
  end
end

#dependencies(expression) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 57

def dependencies(expression)
  ast(expression).dependencies(memory)
end

#disable_cache ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 28

def disable_cache
  @disable_ast_cache = true
  yield(self) if block_given?
ensure
  @disable_ast_cache = false
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dentaku/calculator.rb', line 116

def empty?
  memory.empty?
end

#evaluate(expression, data = {}) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 35

def evaluate(expression, data={})
  evaluate!(expression, data)
rescue UnboundVariableError, ArgumentError
  yield expression if block_given?
end

#evaluate!(expression, data = {}) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 41

def evaluate!(expression, data={})
  store(data) do
    node = expression
    node = ast(node) unless node.is_a?(AST::Node)
    node.value(memory)
  end
end

#solve(expression_hash, &block) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 53

def solve(expression_hash, &block)
  BulkExpressionSolver.new(expression_hash, self).solve(&block)
end

#solve!(expression_hash) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 49

def solve!(expression_hash)
  BulkExpressionSolver.new(expression_hash, self).solve!
end

#store(key_or_hash, value = nil) ⇒ Object Also known as: bind 



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# File 'lib/dentaku/calculator.rb', line 82

def store(key_or_hash, value=nil)
  restore = Hash[memory]

  if value.nil?
    key_or_hash.each do |key, val|
      memory[key.to_s.downcase] = val
    end
  else
    memory[key_or_hash.to_s.downcase] = value
  end

  if block_given?
    begin
      result = yield
      @memory = restore
      return result
    rescue => e
      @memory = restore
      raise e
    end
  end

  self
end

#store_formula(key, formula) ⇒ Object 



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# File 'lib/dentaku/calculator.rb', line 108

def store_formula(key, formula)
  store(key, ast(formula))
end