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Diffstat (limited to 'lib/csv/table.rb')
| -rw-r--r-- | lib/csv/table.rb | 402 |
1 files changed, 0 insertions, 402 deletions
diff --git a/lib/csv/table.rb b/lib/csv/table.rb deleted file mode 100644 index 71eb885de5..0000000000 --- a/lib/csv/table.rb +++ /dev/null @@ -1,402 +0,0 @@ -# frozen_string_literal: true - -require "forwardable" - -class CSV - # - # A CSV::Table is a two-dimensional data structure for representing CSV - # documents. Tables allow you to work with the data by row or column, - # manipulate the data, and even convert the results back to CSV, if needed. - # - # All tables returned by CSV will be constructed from this class, if header - # row processing is activated. - # - class Table - # - # Construct a new CSV::Table from +array_of_rows+, which are expected - # to be CSV::Row objects. All rows are assumed to have the same headers. - # - # The optional +headers+ parameter can be set to Array of headers. - # If headers aren't set, headers are fetched from CSV::Row objects. - # Otherwise, headers() method will return headers being set in - # headers argument. - # - # A CSV::Table object supports the following Array methods through - # delegation: - # - # * empty?() - # * length() - # * size() - # - def initialize(array_of_rows, headers: nil) - @table = array_of_rows - @headers = headers - unless @headers - if @table.empty? - @headers = [] - else - @headers = @table.first.headers - end - end - - @mode = :col_or_row - end - - # The current access mode for indexing and iteration. - attr_reader :mode - - # Internal data format used to compare equality. - attr_reader :table - protected :table - - ### Array Delegation ### - - extend Forwardable - def_delegators :@table, :empty?, :length, :size - - # - # Returns a duplicate table object, in column mode. This is handy for - # chaining in a single call without changing the table mode, but be aware - # that this method can consume a fair amount of memory for bigger data sets. - # - # This method returns the duplicate table for chaining. Don't chain - # destructive methods (like []=()) this way though, since you are working - # with a duplicate. - # - def by_col - self.class.new(@table.dup).by_col! - end - - # - # Switches the mode of this table to column mode. All calls to indexing and - # iteration methods will work with columns until the mode is changed again. - # - # This method returns the table and is safe to chain. - # - def by_col! - @mode = :col - - self - end - - # - # Returns a duplicate table object, in mixed mode. This is handy for - # chaining in a single call without changing the table mode, but be aware - # that this method can consume a fair amount of memory for bigger data sets. - # - # This method returns the duplicate table for chaining. Don't chain - # destructive methods (like []=()) this way though, since you are working - # with a duplicate. - # - def by_col_or_row - self.class.new(@table.dup).by_col_or_row! - end - - # - # Switches the mode of this table to mixed mode. All calls to indexing and - # iteration methods will use the default intelligent indexing system until - # the mode is changed again. In mixed mode an index is assumed to be a row - # reference while anything else is assumed to be column access by headers. - # - # This method returns the table and is safe to chain. - # - def by_col_or_row! - @mode = :col_or_row - - self - end - - # - # Returns a duplicate table object, in row mode. This is handy for chaining - # in a single call without changing the table mode, but be aware that this - # method can consume a fair amount of memory for bigger data sets. - # - # This method returns the duplicate table for chaining. Don't chain - # destructive methods (like []=()) this way though, since you are working - # with a duplicate. - # - def by_row - self.class.new(@table.dup).by_row! - end - - # - # Switches the mode of this table to row mode. All calls to indexing and - # iteration methods will work with rows until the mode is changed again. - # - # This method returns the table and is safe to chain. - # - def by_row! - @mode = :row - - self - end - - # - # Returns the headers for the first row of this table (assumed to match all - # other rows). The headers Array passed to CSV::Table.new is returned for - # empty tables. - # - def headers - if @table.empty? - @headers.dup - else - @table.first.headers - end - end - - # - # In the default mixed mode, this method returns rows for index access and - # columns for header access. You can force the index association by first - # calling by_col!() or by_row!(). - # - # Columns are returned as an Array of values. Altering that Array has no - # effect on the table. - # - def [](index_or_header) - if @mode == :row or # by index - (@mode == :col_or_row and (index_or_header.is_a?(Integer) or index_or_header.is_a?(Range))) - @table[index_or_header] - else # by header - @table.map { |row| row[index_or_header] } - end - end - - # - # In the default mixed mode, this method assigns rows for index access and - # columns for header access. You can force the index association by first - # calling by_col!() or by_row!(). - # - # Rows may be set to an Array of values (which will inherit the table's - # headers()) or a CSV::Row. - # - # Columns may be set to a single value, which is copied to each row of the - # column, or an Array of values. Arrays of values are assigned to rows top - # to bottom in row major order. Excess values are ignored and if the Array - # does not have a value for each row the extra rows will receive a +nil+. - # - # Assigning to an existing column or row clobbers the data. Assigning to - # new columns creates them at the right end of the table. - # - def []=(index_or_header, value) - if @mode == :row or # by index - (@mode == :col_or_row and index_or_header.is_a? Integer) - if value.is_a? Array - @table[index_or_header] = Row.new(headers, value) - else - @table[index_or_header] = value - end - else # set column - unless index_or_header.is_a? Integer - index = @headers.index(index_or_header) || @headers.size - @headers[index] = index_or_header - end - if value.is_a? Array # multiple values - @table.each_with_index do |row, i| - if row.header_row? - row[index_or_header] = index_or_header - else - row[index_or_header] = value[i] - end - end - else # repeated value - @table.each do |row| - if row.header_row? - row[index_or_header] = index_or_header - else - row[index_or_header] = value - end - end - end - end - end - - # - # The mixed mode default is to treat a list of indices as row access, - # returning the rows indicated. Anything else is considered columnar - # access. For columnar access, the return set has an Array for each row - # with the values indicated by the headers in each Array. You can force - # column or row mode using by_col!() or by_row!(). - # - # You cannot mix column and row access. - # - def values_at(*indices_or_headers) - if @mode == :row or # by indices - ( @mode == :col_or_row and indices_or_headers.all? do |index| - index.is_a?(Integer) or - ( index.is_a?(Range) and - index.first.is_a?(Integer) and - index.last.is_a?(Integer) ) - end ) - @table.values_at(*indices_or_headers) - else # by headers - @table.map { |row| row.values_at(*indices_or_headers) } - end - end - - # - # Adds a new row to the bottom end of this table. You can provide an Array, - # which will be converted to a CSV::Row (inheriting the table's headers()), - # or a CSV::Row. - # - # This method returns the table for chaining. - # - def <<(row_or_array) - if row_or_array.is_a? Array # append Array - @table << Row.new(headers, row_or_array) - else # append Row - @table << row_or_array - end - - self # for chaining - end - - # - # A shortcut for appending multiple rows. Equivalent to: - # - # rows.each { |row| self << row } - # - # This method returns the table for chaining. - # - def push(*rows) - rows.each { |row| self << row } - - self # for chaining - end - - # - # Removes and returns the indicated columns or rows. In the default mixed - # mode indices refer to rows and everything else is assumed to be a column - # headers. Use by_col!() or by_row!() to force the lookup. - # - def delete(*indexes_or_headers) - if indexes_or_headers.empty? - raise ArgumentError, "wrong number of arguments (given 0, expected 1+)" - end - deleted_values = indexes_or_headers.map do |index_or_header| - if @mode == :row or # by index - (@mode == :col_or_row and index_or_header.is_a? Integer) - @table.delete_at(index_or_header) - else # by header - if index_or_header.is_a? Integer - @headers.delete_at(index_or_header) - else - @headers.delete(index_or_header) - end - @table.map { |row| row.delete(index_or_header).last } - end - end - if indexes_or_headers.size == 1 - deleted_values[0] - else - deleted_values - end - end - - # - # Removes any column or row for which the block returns +true+. In the - # default mixed mode or row mode, iteration is the standard row major - # walking of rows. In column mode, iteration will +yield+ two element - # tuples containing the column name and an Array of values for that column. - # - # This method returns the table for chaining. - # - # If no block is given, an Enumerator is returned. - # - def delete_if(&block) - return enum_for(__method__) { @mode == :row or @mode == :col_or_row ? size : headers.size } unless block_given? - - if @mode == :row or @mode == :col_or_row # by index - @table.delete_if(&block) - else # by header - deleted = [] - headers.each do |header| - deleted << delete(header) if yield([header, self[header]]) - end - end - - self # for chaining - end - - include Enumerable - - # - # In the default mixed mode or row mode, iteration is the standard row major - # walking of rows. In column mode, iteration will +yield+ two element - # tuples containing the column name and an Array of values for that column. - # - # This method returns the table for chaining. - # - # If no block is given, an Enumerator is returned. - # - def each(&block) - return enum_for(__method__) { @mode == :col ? headers.size : size } unless block_given? - - if @mode == :col - headers.each { |header| yield([header, self[header]]) } - else - @table.each(&block) - end - - self # for chaining - end - - # Returns +true+ if all rows of this table ==() +other+'s rows. - def ==(other) - return @table == other.table if other.is_a? CSV::Table - @table == other - end - - # - # Returns the table as an Array of Arrays. Headers will be the first row, - # then all of the field rows will follow. - # - def to_a - array = [headers] - @table.each do |row| - array.push(row.fields) unless row.header_row? - end - - array - end - - # - # Returns the table as a complete CSV String. Headers will be listed first, - # then all of the field rows. - # - # This method assumes you want the Table.headers(), unless you explicitly - # pass <tt>:write_headers => false</tt>. - # - def to_csv(write_headers: true, **options) - array = write_headers ? [headers.to_csv(options)] : [] - @table.each do |row| - array.push(row.fields.to_csv(options)) unless row.header_row? - end - - array.join("") - 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, *index_or_headers) - value = self[index_or_header] - if value.nil? - nil - elsif index_or_headers.empty? - value - else - unless value.respond_to?(:dig) - raise TypeError, "#{value.class} does not have \#dig method" - end - value.dig(*index_or_headers) - end - end - - # Shows the mode and size of this table in a US-ASCII String. - def inspect - "#<#{self.class} mode:#{@mode} row_count:#{to_a.size}>".encode("US-ASCII") - end - end -end |