/src/lib/io/internal/path_joiner.e

  1-- This file is part of a Liberty Eiffel library.
  2-- See the full copyright at the end.
  3--
  4deferred class PATH_JOINER
  5   -- A protocol for PATH_NAMEs to describe themselves to other objects.
  6   --
  7   -- A typical session goes like this:
  8   -- # call `start_join' describing you drive (if any) and whether you are absolute or relative
  9   -- # Repeatedly call the `join_xxx' procedures to describe yourself, more significant elements first (i.e.
 10   --   generally left-to-right)
 11   -- # call `end_join'
 12   --
 13   -- Caveat: the only way to make sure that the target is not changed at all is by not starting a session. A
 14   -- call to `start_join' (even with `drive'=Void and absoluteness=0) immediately followed by a call to
 15   -- `end_join' can have some benign side-effect on the target (including some amount of normalization being performed).
 16
 17feature {PATH_JOINER}
 18   start_join (drive: STRING; absoluteness: INTEGER)
 19         -- Start joining an absolute path to `Current'
 20         --
 21         -- `drive' is optional
 22         -- `absoluteness' is, e.g., the number of leading slashes:
 23         --   0 for relative paths
 24         --   1 for absolute paths
 25         --   more for super-absolute paths (for instance, network-wide)
 26      require
 27         absoluteness >= 0
 28      deferred
 29      end
 30
 31   join_directory (element: STRING)
 32         -- Add a directory to the end of the path
 33      require
 34         element /= Void
 35      do
 36         join_element(element)
 37      ensure
 38         old join_error implies join_error
 39      end
 40
 41   join_up
 42         -- Go up one directory
 43      deferred
 44      ensure
 45         old join_error implies join_error
 46      end
 47
 48   join_file (element: STRING)
 49         -- Add a file to the end of the path
 50      require
 51         element /= Void
 52      do
 53         join_element(element)
 54      ensure
 55         old join_error implies join_error
 56      end
 57
 58   join_element (element: STRING)
 59         -- Add an unspecified element (directory or file) to the end of the path
 60      require
 61         element /= Void
 62      deferred
 63      ensure
 64         old join_error implies join_error
 65      end
 66
 67   join_extension (an_extension: STRING)
 68         -- Add an extension to the last element of the path
 69      require
 70         an_extension /= Void
 71      deferred
 72      ensure
 73         old join_error implies join_error
 74      end
 75
 76   end_join
 77         -- Finish joining the path
 78      deferred
 79      ensure
 80         old join_error implies join_error
 81      end
 82
 83   join_error: BOOLEAN
 84         -- Did an error occur during joining
 85      deferred
 86      end
 87
 88end -- class PATH_JOINER
 89--
 90-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
 91--
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 93-- of this software and associated documentation files (the "Software"), to deal
 94-- in the Software without restriction, including without limitation the rights
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 96-- copies of the Software, and to permit persons to whom the Software is
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 98--
 99-- The above copyright notice and this permission notice shall be included in
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101--
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