/src/lib/io/core/input_stream.e

  1-- This file is part of a Liberty Eiffel library.
  2-- See the full copyright at the end.
  3--
  4deferred class INPUT_STREAM
  5   --
  6   -- An input stream is a flow of characters that can be read from some source (be it an Eiffel object or an
  7   -- external object)
  8   --
  9   -- Input stream usage is available in tutorial/io and Liberty Eiffel FAQ.
 10   --
 11
 12inherit
 13   STREAM
 14
 15insert
 16   INPUT_STREAM_TOOLS
 17   FILTERABLE
 18      redefine filter
 19      end
 20
 21feature {ANY}
 22   read_character
 23      do
 24         filtered_read_character
 25      ensure then
 26         is_connected
 27      end
 28
 29   read_line_in (buffer: STRING)
 30      do
 31         filtered_read_line_in(buffer)
 32      end
 33
 34   read_available_in (buffer: STRING; limit: INTEGER)
 35      do
 36         filtered_read_available_in(buffer, limit)
 37      end
 38
 39   unread_character
 40      do
 41         filtered_unread_character
 42      ensure
 43         not end_of_input
 44      end
 45
 46   last_character: CHARACTER
 47      do
 48         Result := filtered_last_character
 49      ensure
 50         is_connected
 51         not end_of_input
 52      end
 53
 54   detach
 55      do
 56         if filter /= Void then
 57            filter.do_detach
 58            filter := Void
 59         end
 60      end
 61
 62feature {FILTER_INPUT_STREAM}
 63   filtered_read_character
 64      require
 65         is_connected
 66         can_read_character
 67      deferred
 68      end
 69
 70   filtered_unread_character
 71      require
 72         is_connected
 73         can_unread_character
 74      deferred
 75      end
 76
 77   filtered_last_character: CHARACTER
 78      require
 79         is_connected
 80         valid_last_character
 81      deferred
 82      end
 83
 84   filtered_read_available_in (buffer: STRING; limit: INTEGER)
 85      require
 86         is_connected
 87         buffer /= Void
 88      local
 89         i: INTEGER
 90      do
 91         -- Default implementation
 92         if can_read_character then
 93            from
 94               i := 1
 95               filtered_read_character
 96            until
 97               end_of_input or else not can_read_character or else i > limit
 98            loop
 99               buffer.extend(filtered_last_character)
100               filtered_read_character
101               i := i + 1
102            end
103            if i > limit then
104               filtered_unread_character
105            end
106         end
107      end
108
109   filtered_read_line_in (buffer: STRING)
110      require
111         is_connected
112         buffer /= Void
113      do
114         -- Default implementation
115         if can_read_character then
116            from
117               filtered_read_character
118            until
119               end_of_input or else not can_read_character or else filtered_last_character = '%N'
120            loop
121               inspect
122                  filtered_last_character
123               when '%R' then
124                  if can_read_character then
125                     filtered_read_character
126                     if filtered_last_character /= '%N' then
127                        buffer.extend('%R')
128                        buffer.extend(filtered_last_character)
129                        filtered_read_character
130                     end
131                  end
132               when '%N' then
133               else
134                  buffer.extend(filtered_last_character)
135                  filtered_read_character
136               end
137            end
138         end
139      end
140
141feature {FILTER}
142   filter: FILTER_INPUT_STREAM
143
144feature {ANY}
145   event_can_read: EVENT_DESCRIPTOR
146      do
147         Result := can_read
148         if Result = Void then
149            create can_read.make(Current)
150            Result := can_read
151         end
152      end
153
154feature {}
155   can_read: CAN_READ_DATA_FROM_STREAM
156
157   new_url: URL
158      do
159         create Result.from_stream(Current, True, False)
160      end
161
162end -- class INPUT_STREAM
163--
164-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
165--
166-- Permission is hereby granted, free of charge, to any person obtaining a copy
167-- of this software and associated documentation files (the "Software"), to deal
168-- in the Software without restriction, including without limitation the rights
169-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
170-- copies of the Software, and to permit persons to whom the Software is
171-- furnished to do so, subject to the following conditions:
172--
173-- The above copyright notice and this permission notice shall be included in
174-- all copies or substantial portions of the Software.
175--
176-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
177-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
178-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
179-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
180-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
181-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
182-- THE SOFTWARE.