Add bin and edit workflow

bin/gems/pry-0.15.2/lib/pry/commands/amend_line.rb

@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+
+class Pry
+  class Command
+    class AmendLine < Pry::ClassCommand
+      match(/amend-line(?: (-?\d+)(?:\.\.(-?\d+))?)?/)
+      group 'Editing'
+      description 'Amend a line of input in multi-line mode.'
+      command_options interpolate: false, listing: 'amend-line'
+
+      banner <<-'BANNER'
+        Amend a line of input in multi-line mode. `amend-line N`, where the N represents
+        line to replace. Can also specify a range of lines using `amend-line N..M`
+        syntax. Passing "!" as replacement content deletes the line(s) instead.
+
+        amend-line 1 puts 'new'    # replace line 1
+        amend-line 1..4 !          # delete lines 1..4
+        amend-line 3 >puts 'bye'   # insert before line 3
+        amend-line puts 'appended' # no line number modifies immediately preceding line
+      BANNER
+
+      def process
+        raise CommandError, "No input to amend." if eval_string.empty?
+
+        eval_string.replace(amend_input)
+        run "fix-indent"
+        run "show-input"
+      end
+
+      private
+
+      # @return [String] A new string with the amendments applied to it.
+      def amend_input
+        input_array = eval_string.each_line.to_a
+
+        if arg_string == "!"
+          delete_from_array(input_array, line_range)
+        elsif arg_string.start_with?(">")
+          insert_into_array(input_array, line_range)
+        else
+          replace_in_array(input_array, line_range)
+        end
+
+        input_array.join
+      end
+
+      def delete_from_array(array, range)
+        array.slice!(range)
+      end
+
+      def insert_into_array(array, range)
+        insert_slot = Array(range).first
+        array.insert(insert_slot, arg_string[1..-1] << "\n")
+      end
+
+      def replace_in_array(array, range)
+        array[range] = arg_string + "\n"
+      end
+
+      # @return [Fixnum] The number of lines currently in `eval_string` (the
+      #   input buffer)
+      def line_count
+        eval_string.lines.count
+      end
+
+      # Returns the (one-indexed) start and end lines given by the user.
+      # The lines in this range will be affected by the `amend-line`.
+      # Returns `nil` if no lines were specified by the user.
+      # @return [Array<Fixnum>, nil]
+      def start_and_end_line_number
+        start_line_number, end_line_number = args
+        end_line_number ||= start_line_number.to_i
+
+        [start_line_number.to_i, end_line_number.to_i] if start_line_number
+      end
+
+      # Takes two numbers that are 1-indexed, and returns a range (or
+      # number) that is 0-indexed. 1-indexed means the first element is
+      # identified by 1 rather than by 0 (as is the case for Ruby arrays).
+      # @param [Fixnum] start_line_number One-indexed number.
+      # @param [Fixnum] end_line_number One-indexed number.
+      # @return [Range] The zero-indexed range.
+      def zero_indexed_range_from_one_indexed_numbers(start_line_number, end_line_number)
+        # FIXME: one_index_number is a horrible name for this method
+        one_index_number(start_line_number)..one_index_number(end_line_number)
+      end
+
+      # The lines (or line) that will be modified by the `amend-line`.
+      # @return [Range, Fixnum] The lines or line.
+      def line_range
+        start_line_number, end_line_number = start_and_end_line_number
+        if start_line_number
+          zero_indexed_range_from_one_indexed_numbers(start_line_number,
+                                                      end_line_number)
+        else
+          line_count - 1
+        end
+      end
+    end
+
+    Pry::Commands.add_command(Pry::Command::AmendLine)
+  end
+end