Module: Ytry::Try

Includes:
Enumerable
Included in:
Failure, Success
Defined in:
lib/ytry.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.ary_to_type(value) ⇒ Object 



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# File 'lib/ytry.rb', line 14

def self.ary_to_type value
  raise Try.invalid_argument('Argument must be an array-like object', value) unless value.respond_to? :to_ary
  return value if value.is_a? Try
  value.to_ary.empty? ?
    Failure.new(RuntimeError.new("Element not found").tap{|ex| ex.set_backtrace(caller)}) :
    Success.new(value.to_ary.first)
end

.zip(*try_array) ⇒ Object 



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# File 'lib/ytry.rb', line 21

def self.zip *try_array
  first_failure = try_array.find(&:empty?)
  first_failure.nil? ? Success.new(try_array.map(&:get)) : first_failure
end

Instance Method Details

#each ⇒ Object Also known as: on_success 



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# File 'lib/ytry.rb', line 25

def each
  return enum_for(__method__) unless block_given?
  Try { yield self.get unless empty? }
  return self
end

#flat_map(&block) ⇒ Object Also known as: collect_concat 



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# File 'lib/ytry.rb', line 52

def flat_map &block
  block or return enum_for(method)
  return self if self.empty?
  wrapped_result = Try{block.call(self.get)}
  return wrapped_result if (!wrapped_result.empty? && !wrapped_result.get.respond_to?(:to_ary))
  Try.ary_to_type(wrapped_result.flatten)
end

#flatten(level = 1) ⇒ Object 



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# File 'lib/ytry.rb', line 67

def flatten level = 1
  level.times.reduce(self) { |current, _|
    break(current) if current.empty?
    Try.ary_to_type current.get
  }
end

#get_or_else ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/ytry.rb', line 88

def get_or_else
  raise ArgumentError, 'missing block' unless block_given?
  return self.get unless empty?
  yield
end

#grep(pattern) ⇒ Object 



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# File 'lib/ytry.rb', line 60

def grep pattern
  return self if self.empty?
  match = Try {
    (pattern === self.get) ? self.get : (raise RuntimeError.new("Element not found"))
  }
  block_given? ? match.map{|v| yield v} : match
end

#inspect ⇒ Object 



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# File 'lib/ytry.rb', line 93

def inspect() to_s end

#map(&block) ⇒ Object Also known as: collect 



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# File 'lib/ytry.rb', line 35

def map &block
  block or return enum_for(__method__)
  self.empty? ? self : Try{block.call(self.get)}
end

#on_failure ⇒ Object 



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# File 'lib/ytry.rb', line 31

def on_failure
  return enum_for(__method__) unless block_given?
  return self
end

#or_else ⇒ Object 



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# File 'lib/ytry.rb', line 79

def or_else
  return self unless empty?
  candidate = Try{ yield }
  if (!candidate.empty? && !candidate.get.is_a?(Try))
    raise(Try.invalid_argument('Block should evaluate to an instance of Try', candidate.get))
  else
    candidate.flatten
  end
end

#reject(&block) ⇒ Object 



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# File 'lib/ytry.rb', line 47

def reject &block
  if block_given? then select {|v| ! block.call(v)}
  else enum_for(__method__)
  end
end

#select(&block) ⇒ Object 



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# File 'lib/ytry.rb', line 40

def select &block
  block or return enum_for(__method__)
  return self if empty?
  predicate = Try{ block.call(self.get) }
  return predicate if predicate.empty?
  predicate.get ? self : Try.ary_to_type([])
end

#zip(*others) ⇒ Object 



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# File 'lib/ytry.rb', line 73

def zip *others
  Try.zip(self, *others)
end

#|(lambda) ⇒ Object 



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# File 'lib/ytry.rb', line 76

def | lambda
  self.flat_map &lambda # slow but easy to read + supports symbols out of the box
end