Class: Plurimath::Formatter::Numbers::DigitSequence

Inherits:
Object
  • Object
show all
Defined in:
lib/plurimath/formatter/numbers/digit_sequence.rb

Overview

Shared base-digit helper for counting, rounding thresholds, next-digit lookup, and carry propagation.

Constant Summary collapse

ZERO = 
"0"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base:) ⇒ DigitSequence

Returns a new instance of DigitSequence.



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 13

def initialize(base:)
  @base = base
end

Instance Attribute Details

#base ⇒ Object (readonly)

Returns the value of attribute base.



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 9

def base
  @base
end

Instance Method Details

#digit?(char) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 17

def digit?(char)
  Base::DIGIT_VALUE.key?(char)
end

#digit_count(chars, stop_at: nil) ⇒ Object 



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 25

def digit_count(chars, stop_at: nil)
  count = 0
  each_countable_digit(chars, stop_at: stop_at) { count += 1 }
  count
end

#increment_reversed(digits, carry: 1, skip: [], overflow: ZERO) ⇒ Object 



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 63

def increment_reversed(digits, carry: 1, skip: [], overflow: ZERO)
  digits = digits.dup
  return [digits, carry] unless carry.positive?

  digits.each_with_index do |digit, index|
    next if skip.include?(digit)
    next unless digit?(digit)

    if max_digit?(digit)
      digits[index] = overflow
    else
      digits[index] = next_digit(digit)
      carry = 0
      break
    end
  end

  [digits, carry]
end

#max_digit?(char) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 43

def max_digit?(char)
  Base::DIGIT_VALUE[char] == base.pred
end

#next_digit(char) ⇒ Object 



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 47

def next_digit(char)
  current_index = Base::DIGIT_VALUE[char]
  return unless current_index

  Base::HEX_ALPHANUMERIC[current_index + 1]
end

#round_up?(char) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 54

def round_up?(char)
  value = Base::DIGIT_VALUE[char]
  !!(value && value >= threshold)
end

#significant?(char) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 21

def significant?(char)
  Base::DIGIT_VALUE[char]&.positive?
end

#significant_digit_count(chars) ⇒ Object 



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 31

def significant_digit_count(chars)
  start_counting = false
  count = 0

  each_countable_digit(chars) do |char|
    start_counting = true if significant?(char)
    count += 1 if start_counting
  end

  count
end

#threshold ⇒ Object 



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# File 'lib/plurimath/formatter/numbers/digit_sequence.rb', line 59

def threshold
  @threshold ||= base.div(2)
end