Module: PlainText::Util

Included in:
PlainText, Part
Defined in:
lib/plain_text/util.rb

Overview

Contains some utility methods for use in this module and classes.

Author:

  • Masa Sakano (Wise Babel Ltd)

Class Method Summary collapse

Class Method Details

.even_odd_arrays(ary, size_even: false, filler: "") ⇒ Object

Returns a pair of Arrays of even and odd number-indices of the original Array

Examples:

even_odd_arrays([33,44,55], size_even: true)
# => [[33, 55], [44, ""]]

Parameters:

  • ary (Array)
  • size_even: (Boolean) (defaults to: false) —

    if true (Def: false), the sizes of the returned arrays are guaranteed to be identical.

  • filler: (Object) (defaults to: "") —

    if size_even: is true and if matching is performed, this filler is added at the end of the last element.



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# File 'lib/plain_text/util.rb', line 23

def even_odd_arrays(ary, size_even: false, filler: "")
  ar_even = select.with_index { |_, i| i.even? } rescue select.each_with_index { |_, i| i.even? } # Rescue for Ruby 2.1 or earlier
  ar_odd  = select.with_index { |_, i| i.odd? }  rescue select.each_with_index { |_, i| i.odd? }  # Rescue for Ruby 2.1 or earlier
  if size_even && (ar_even.size != ar_odd.size)
    ar_odd.push filler
    raise "Should not happern." if (ar_even.size != ar_odd.size)
  end
  [ar_even, ar_odd]
end

.positive_array_index(i, ary) ⇒ Integer, NilClass

Returns a non-negative Array index for self

If positive or zero, it returns i. If the negative index is out of range, it returns nil.

Parameters:

  • i (Integer)
  • ary (Array) —

    Reference Array.

Returns:

  • (Integer, NilClass) —

    nil if out of range to the negative. Note in most cases in Ruby default, it raises IndexError. See the code of #positive_array_index_checked

Raises:

  • (TypeError) —

    if non-integer is specified.

  • (ArgumentError) —

    if ary is not an Array, or more specifically, it does not have size method or ary.size does not return Integer or similar.



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# File 'lib/plain_text/util.rb', line 43

def positive_array_index(i, ary)
  i2 = i.to_int rescue (raise TypeError, sprintf("no implicit conversion of #{i.class} into Integer"))
  return i2 if i2 >= 0
  ret = ary.size + i2 rescue (raise ArgumentError, "argument is not an array.")
  (ret < 0) ? nil : ret
end

.positive_array_index_checked(index_in, ary, accept_too_big: true, varname: nil) ⇒ Integer

Returns a non-negative Array index for self, performing a check.

Exception is raised if it is out of range.

Wrapper for #positive_array_index

Parameters:

  • index_in (Integer) —

    Index to check and convert from. Potentially negative integer.

  • ary (Array) —

    Reference Array.

  • accept_too_big: (Boolean, NilClass) (defaults to: true) —

    if true (Default), a positive index larger than the last array index is returned as it is. If nil, the last index + 1 is accepted but raises an Exception for anything larger. If false, any index larger than the last index raises an Exception.

  • varname: (NilClass, String) (defaults to: nil) —

    Name of the variable (or nil) to be used for error messages.

Returns:

  • (Integer) —

    Non-negative index; i.e., if index=-1 is specified for an Array with a size of 3, the returned value is 2 (the last index of it).

Raises:

  • (IndexError) —

    if the index is out of the range to negative.



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# File 'lib/plain_text/util.rb', line 63

def positive_array_index_checked(index_in, ary, accept_too_big: true, varname: nil)
  # def self.positive_valid_index_for_array(index_in, ary, varname: nil)
  errmsgs = {}
  %w(of for).each do |i|
    errmsgs[i] = (varname ? "." : sprintf(" %s %s.", i, varname)) 
  end
  
  index = positive_array_index(index_in, ary)  # guaranteed to be Integer or nil
  raise IndexError, sprintf("index (%s) too small for array; minimum: -%d", index_in, ary.size) if !index  # Ruby default Error message (except the variable "index" as opposed to "index_in is used in the true Ruby default).
  if index_in >= 0
    last_index = ary.size - 1
    errnote1 = nil
    if    (index >  last_index + 1) && !accept_too_big
      errnote1 = ' (or +1)'
    elsif (index == last_index + 1) && (false == accept_too_big)
      errnote1 = " "
    end
    raise IndexError, sprintf("Specified index (%s) is larger than the last index (%d)%s%s", index_in, last_index, errnote1, errmsgs['of']) if errnote1
  end
  index
end

.raise_typeerror(var, to_class, verbose: $DEBUG) ⇒ Object

Raise TypeError

Call as raise_typeerror(var_name) from instance methods, providing this Module is included in the Class/Module.

Parameters:

  • var (Object)
  • to_class (String, Class) —

    class name converted into.

  • verbose: (Hash) (defaults to: $DEBUG) —

    a customizable set of options

Raises:

  • (TypeError) 


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# File 'lib/plain_text/util.rb', line 94

def raise_typeerror(var, to_class, verbose: $DEBUG)
  msg1 = (verbose ? sprintf("(<= %s)", var.inspect) : "")
  to_class_str = (to_class.name rescue to_class.to_str)
  raise TypeError, sprintf("no implicit conversion of %s%s into %s", var.class, msg1, to_class_str)
end