Method: Hanami::Utils::Kernel.Integer

Defined in:

lib/hanami/utils/kernel.rb

.Integer(arg) ⇒ Fixnum

Coerces the argument to be an Integer.

It’s similar to Ruby’s Kernel.Integer, but it doesn’t stop at the first error and raise an exception only when the argument can’t be coerced.

Examples:

Basic Usage

require 'bigdecimal'
require 'hanami/utils/kernel'

Hanami::Utils::Kernel.Integer(1)                        # => 1
Hanami::Utils::Kernel.Integer(1.2)                      # => 1
Hanami::Utils::Kernel.Integer(011)                      # => 9
Hanami::Utils::Kernel.Integer(0xf5)                     # => 245
Hanami::Utils::Kernel.Integer("1")                      # => 1
Hanami::Utils::Kernel.Integer(Rational(0.3))            # => 0
Hanami::Utils::Kernel.Integer(Complex(0.3))             # => 0
Hanami::Utils::Kernel.Integer(BigDecimal(12.00001))     # => 12
Hanami::Utils::Kernel.Integer(176605528590345446089)
  # => 176605528590345446089

Hanami::Utils::Kernel.Integer(Time.now)                 # => 1396947161

Integer Interface

require 'hanami/utils/kernel'

UltimateAnswer = Struct.new(:question) do
  def to_int
    42
  end
end

answer = UltimateAnswer.new('The Ultimate Question of Life')
Hanami::Utils::Kernel.Integer(answer) # => 42

Error Handling

require 'hanami/utils/kernel'

# nil
Kernel.Integer(nil)               # => TypeError
Hanami::Utils::Kernel.Integer(nil) # => 0

# float represented as a string
Kernel.Integer("23.4")               # => TypeError
Hanami::Utils::Kernel.Integer("23.4") # => 23

# rational represented as a string
Kernel.Integer("2/3")               # => TypeError
Hanami::Utils::Kernel.Integer("2/3") # => 2

# complex represented as a string
Kernel.Integer("2.5/1")               # => TypeError
Hanami::Utils::Kernel.Integer("2.5/1") # => 2

Unchecked Exceptions

require 'date'
require 'bigdecimal'
require 'hanami/utils/kernel'

# Missing #to_int and #to_i
input = OpenStruct.new(color: 'purple')
Hanami::Utils::Kernel.Integer(input) # => TypeError

# String that doesn't represent an integer
input = 'hello'
Hanami::Utils::Kernel.Integer(input) # => TypeError

# When true
input = true
Hanami::Utils::Kernel.Integer(input) # => TypeError

# When false
input = false
Hanami::Utils::Kernel.Integer(input) # => TypeError

# When Date
input = Date.today
Hanami::Utils::Kernel.Integer(input) # => TypeError

# When DateTime
input = DateTime.now
Hanami::Utils::Kernel.Integer(input) # => TypeError

# bigdecimal infinity
input = BigDecimal("Infinity")
Hanami::Utils::Kernel.Integer(input) # => TypeError

# bigdecimal NaN
input = BigDecimal("NaN")
Hanami::Utils::Kernel.Integer(input) # => TypeError

# big rational
input = Rational(-8) ** Rational(1, 3)
Hanami::Utils::Kernel.Integer(input) # => TypeError

# big complex represented as a string
input = Complex(2, 3)
Hanami::Utils::Kernel.Integer(input) # => TypeError

Parameters:

• arg (Object) —

  the argument

Returns:

• (Fixnum) —

  the result of the coercion

Raises:

• (TypeError) —

  if the argument can’t be coerced

See Also:

• http://www.ruby-doc.org/core/Kernel.html#method-i-Integer

Since:

• 0.1.1

# File 'lib/hanami/utils/kernel.rb', line 331

def self.Integer(arg)
  super
rescue ArgumentError, TypeError, NoMethodError
  begin
    case arg
    when NilClass, ->(a) { a.respond_to?(:to_i) && numeric?(a) }
      arg.to_i
    else
      raise TypeError.new "can't convert #{inspect_type_error(arg)}into Integer"
    end
  rescue NoMethodError
    raise TypeError.new "can't convert #{inspect_type_error(arg)}into Integer"
  end
rescue RangeError
  raise TypeError.new "can't convert #{inspect_type_error(arg)}into Integer"
end