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Editing: row.rb
# frozen_string_literal: true require "forwardable" class CSV # # A CSV::Row is part Array and part Hash. It retains an order for the fields # and allows duplicates just as an Array would, but also allows you to access # fields by name just as you could if they were in a Hash. # # All rows returned by CSV will be constructed from this class, if header row # processing is activated. # class Row # # Constructs a new CSV::Row from +headers+ and +fields+, which are expected # to be Arrays. If one Array is shorter than the other, it will be padded # with +nil+ objects. # # The optional +header_row+ parameter can be set to +true+ to indicate, via # CSV::Row.header_row?() and CSV::Row.field_row?(), that this is a header # row. Otherwise, the row assumes to be a field row. # # A CSV::Row object supports the following Array methods through delegation: # # * empty?() # * length() # * size() # def initialize(headers, fields, header_row = false) @header_row = header_row headers.each { |h| h.freeze if h.is_a? String } # handle extra headers or fields @row = if headers.size >= fields.size headers.zip(fields) else fields.zip(headers).each(&:reverse!) end end # Internal data format used to compare equality. attr_reader :row protected :row ### Array Delegation ### extend Forwardable def_delegators :@row, :empty?, :length, :size def initialize_copy(other) super @row = @row.dup end # Returns +true+ if this is a header row. def header_row? @header_row end # Returns +true+ if this is a field row. def field_row? not header_row? end # Returns the headers of this row. def headers @row.map(&:first) end # # :call-seq: # field( header ) # field( header, offset ) # field( index ) # # This method will return the field value by +header+ or +index+. If a field # is not found, +nil+ is returned. # # When provided, +offset+ ensures that a header match occurs on or later # than the +offset+ index. You can use this to find duplicate headers, # without resorting to hard-coding exact indices. # def field(header_or_index, minimum_index = 0) # locate the pair finder = (header_or_index.is_a?(Integer) || header_or_index.is_a?(Range)) ? :[] : :assoc pair = @row[minimum_index..-1].send(finder, header_or_index) # return the field if we have a pair if pair.nil? nil else header_or_index.is_a?(Range) ? pair.map(&:last) : pair.last end end alias_method :[], :field # # :call-seq: # fetch( header ) # fetch( header ) { |row| ... } # fetch( header, default ) # # This method will fetch the field value by +header+. It has the same # behavior as Hash#fetch: if there is a field with the given +header+, its # value is returned. Otherwise, if a block is given, it is yielded the # +header+ and its result is returned; if a +default+ is given as the # second argument, it is returned; otherwise a KeyError is raised. # def fetch(header, *varargs) raise ArgumentError, "Too many arguments" if varargs.length > 1 pair = @row.assoc(header) if pair pair.last else if block_given? yield header elsif varargs.empty? raise KeyError, "key not found: #{header}" else varargs.first end end end # Returns +true+ if there is a field with the given +header+. def has_key?(header) !!@row.assoc(header) end alias_method :include?, :has_key? alias_method :key?, :has_key? alias_method :member?, :has_key? alias_method :header?, :has_key? # # :call-seq: # []=( header, value ) # []=( header, offset, value ) # []=( index, value ) # # Looks up the field by the semantics described in CSV::Row.field() and # assigns the +value+. # # Assigning past the end of the row with an index will set all pairs between # to <tt>[nil, nil]</tt>. Assigning to an unused header appends the new # pair. # def []=(*args) value = args.pop if args.first.is_a? Integer if @row[args.first].nil? # extending past the end with index @row[args.first] = [nil, value] @row.map! { |pair| pair.nil? ? [nil, nil] : pair } else # normal index assignment @row[args.first][1] = value end else index = index(*args) if index.nil? # appending a field self << [args.first, value] else # normal header assignment @row[index][1] = value end end end # # :call-seq: # <<( field ) # <<( header_and_field_array ) # <<( header_and_field_hash ) # # If a two-element Array is provided, it is assumed to be a header and field # and the pair is appended. A Hash works the same way with the key being # the header and the value being the field. Anything else is assumed to be # a lone field which is appended with a +nil+ header. # # This method returns the row for chaining. # def <<(arg) if arg.is_a?(Array) and arg.size == 2 # appending a header and name @row << arg elsif arg.is_a?(Hash) # append header and name pairs arg.each { |pair| @row << pair } else # append field value @row << [nil, arg] end self # for chaining end # # A shortcut for appending multiple fields. Equivalent to: # # args.each { |arg| csv_row << arg } # # This method returns the row for chaining. # def push(*args) args.each { |arg| self << arg } self # for chaining end # # :call-seq: # delete( header ) # delete( header, offset ) # delete( index ) # # Removes a pair from the row by +header+ or +index+. The pair is # located as described in CSV::Row.field(). The deleted pair is returned, # or +nil+ if a pair could not be found. # def delete(header_or_index, minimum_index = 0) if header_or_index.is_a? Integer # by index @row.delete_at(header_or_index) elsif i = index(header_or_index, minimum_index) # by header @row.delete_at(i) else [ ] end end # # The provided +block+ is passed a header and field for each pair in the row # and expected to return +true+ or +false+, depending on whether the pair # should be deleted. # # This method returns the row for chaining. # # If no block is given, an Enumerator is returned. # def delete_if(&block) return enum_for(__method__) { size } unless block_given? @row.delete_if(&block) self # for chaining end # # This method accepts any number of arguments which can be headers, indices, # Ranges of either, or two-element Arrays containing a header and offset. # Each argument will be replaced with a field lookup as described in # CSV::Row.field(). # # If called with no arguments, all fields are returned. # def fields(*headers_and_or_indices) if headers_and_or_indices.empty? # return all fields--no arguments @row.map(&:last) else # or work like values_at() all = [] headers_and_or_indices.each do |h_or_i| if h_or_i.is_a? Range index_begin = h_or_i.begin.is_a?(Integer) ? h_or_i.begin : index(h_or_i.begin) index_end = h_or_i.end.is_a?(Integer) ? h_or_i.end : index(h_or_i.end) new_range = h_or_i.exclude_end? ? (index_begin...index_end) : (index_begin..index_end) all.concat(fields.values_at(new_range)) else all << field(*Array(h_or_i)) end end return all end end alias_method :values_at, :fields # # :call-seq: # index( header ) # index( header, offset ) # # This method will return the index of a field with the provided +header+. # The +offset+ can be used to locate duplicate header names, as described in # CSV::Row.field(). # def index(header, minimum_index = 0) # find the pair index = headers[minimum_index..-1].index(header) # return the index at the right offset, if we found one index.nil? ? nil : index + minimum_index end # # Returns +true+ if +data+ matches a field in this row, and +false+ # otherwise. # def field?(data) fields.include? data end include Enumerable # # Yields each pair of the row as header and field tuples (much like # iterating over a Hash). This method returns the row for chaining. # # If no block is given, an Enumerator is returned. # # Support for Enumerable. # def each(&block) return enum_for(__method__) { size } unless block_given? @row.each(&block) self # for chaining end alias_method :each_pair, :each # # Returns +true+ if this row contains the same headers and fields in the # same order as +other+. # def ==(other) return @row == other.row if other.is_a? CSV::Row @row == other end # # Collapses the row into a simple Hash. Be warned that this discards field # order and clobbers duplicate fields. # def to_h hash = {} each do |key, _value| hash[key] = self[key] unless hash.key?(key) end hash end alias_method :to_hash, :to_h alias_method :to_ary, :to_a # # Returns the row as a CSV String. Headers are not used. Equivalent to: # # csv_row.fields.to_csv( options ) # def to_csv(**options) fields.to_csv(**options) end alias_method :to_s, :to_csv # # Extracts the nested value specified by the sequence of +index+ or +header+ objects by calling dig at each step, # returning nil if any intermediate step is nil. # def dig(index_or_header, *indexes) value = field(index_or_header) if value.nil? nil elsif indexes.empty? value else unless value.respond_to?(:dig) raise TypeError, "#{value.class} does not have \#dig method" end value.dig(*indexes) end end # # A summary of fields, by header, in an ASCII compatible String. # def inspect str = ["#<", self.class.to_s] each do |header, field| str << " " << (header.is_a?(Symbol) ? header.to_s : header.inspect) << ":" << field.inspect end str << ">" begin str.join('') rescue # any encoding error str.map do |s| e = Encoding::Converter.asciicompat_encoding(s.encoding) e ? s.encode(e) : s.force_encoding("ASCII-8BIT") end.join('') end end end end
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