Module: RegexpExamples

Defined in:
lib/regexp-examples/parser.rb,
lib/regexp-examples/groups.rb,
lib/regexp-examples/helpers.rb,
lib/regexp-examples/version.rb,
lib/regexp-examples/constants.rb,
lib/regexp-examples/repeaters.rb,
lib/regexp-examples/backreferences.rb,
lib/regexp-examples/chargroup_parser.rb,
lib/regexp-examples/max_results_limiter.rb,
lib/regexp-examples/unicode_char_ranges.rb,
lib/regexp-examples/parser_helpers/parse_group_helper.rb,
lib/regexp-examples/parser_helpers/parse_repeater_helper.rb,
lib/regexp-examples/parser_helpers/charset_negation_helper.rb,
lib/regexp-examples/parser_helpers/parse_multi_group_helper.rb,
lib/regexp-examples/parser_helpers/parse_after_backslash_group_helper.rb

Overview

A common helper used throughout various parser methods

Defined Under Namespace

Modules: CharsetNegationHelper, GroupWithIgnoreCase, ParseAfterBackslashGroupHelper, ParseGroupHelper, ParseMultiGroupHelper, ParseRepeaterHelper, RandomResultBySample Classes: BackReferenceGroup, BackReferenceReplacer, BaseRepeater, CharGroup, ChargroupParser, Config, DotGroup, GroupResult, MaxResultsLimiter, MaxResultsLimiterByProduct, MaxResultsLimiterBySum, MultiGroup, OneTimeRepeater, OrGroup, Parser, PlaceHolderGroup, PlusRepeater, QuestionMarkRepeater, RangeRepeater, SingleCharGroup, StarRepeater, UnicodeCharRanges

Constant Summary collapse

IllegalSyntaxError = 
Class.new(StandardError)
VERSION = 
'1.4.0'.freeze
BackslashCharMap =

Map of special regex characters, to their associated character sets

{
  'd' => CharSets::Digit,
  'D' => CharSets::Any - CharSets::Digit,
  'w' => CharSets::Word,
  'W' => CharSets::Any - CharSets::Word,
  's' => CharSets::Whitespace,
  'S' => CharSets::Any - CharSets::Whitespace,
  'h' => CharSets::Hex,
  'H' => CharSets::Any - CharSets::Hex,

  't' => ["\t"], # tab
  'n' => ["\n"], # new line
  'r' => ["\r"], # carriage return
  'f' => ["\f"], # form feed
  'a' => ["\a"], # alarm
  'v' => ["\v"], # vertical tab
  'e' => ["\e"], # escape
}.freeze
POSIXCharMap = 
{
  'alnum'  => CharSets::Upper | CharSets::Lower | CharSets::Digit,
  'alpha'  => CharSets::Upper | CharSets::Lower,
  'blank'  => [' ', "\t"],
  'cntrl'  => CharSets::Control,
  'digit'  => CharSets::Digit,
  'graph'  => (CharSets::Any - CharSets::Control) - [' '], #  Visible chars
  'lower'  => CharSets::Lower,
  'print'  => CharSets::Any - CharSets::Control,
  'punct'  => CharSets::Punct,
  'space'  => CharSets::Whitespace,
  'upper'  => CharSets::Upper,
  'xdigit' => CharSets::Hex,
  'word'   => CharSets::Word,
  'ascii'  => CharSets::Any
}.freeze
NamedPropertyCharMap = 
UnicodeCharRanges.new

Class Method Summary collapse

Class Method Details

.generic_map_result(repeaters, method) ⇒ Object 



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# File 'lib/regexp-examples/helpers.rb', line 36

def self.generic_map_result(repeaters, method)
  permutations_of_strings(
    repeaters.map { |repeater| repeater.public_send(method) }
  )
end

.join_preserving_capture_groups(result) ⇒ Object 



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# File 'lib/regexp-examples/helpers.rb', line 24

def self.join_preserving_capture_groups(result)
  # Only save the LAST group from repeated capture groups, because
  # e.g. /([ab]){2} \1/.examples should NOT include "ab a"
  # (Hence the need for "reverse"!)
  subgroups = result
              .flat_map(&:all_subgroups)
              .reverse
              .uniq(&:group_id)

  GroupResult.new(result.join, nil, subgroups)
end

.permutations_of_strings(arrays_of_strings, max_results_limiter = MaxResultsLimiterByProduct.new) ⇒ Object

Given an array of arrays of strings, returns all possible perutations for strings, created by joining one element from each array

For example: permutations_of_strings [ [‘a’], [‘b’], [‘c’, ‘d’, ‘e’] ] #=> [‘abc’, ‘abd’, ‘abe’] permutations_of_strings [ [‘a’, ‘b’], [‘c’, ‘d’] ] #=> [ ‘ac’, ‘ad’, ‘bc’, ‘bd’ ]

Edge case: permutations_of_strings [ [] ] #=> nil (For example, ths occurs during /[^dD]/.examples #=> [])



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# File 'lib/regexp-examples/helpers.rb', line 13

def self.permutations_of_strings(arrays_of_strings,
                                 max_results_limiter = MaxResultsLimiterByProduct.new)
  partial_result = max_results_limiter.limit_results(arrays_of_strings.shift)
  return partial_result if arrays_of_strings.empty?
  partial_result.product(
    permutations_of_strings(arrays_of_strings, max_results_limiter)
  ).map do |result|
    join_preserving_capture_groups(result)
  end
end