/src/lib/regular_expression/regular_expression_builder.e

  1-- This file is part of a Liberty Eiffel library.
  2-- See the full copyright at the end.
  3--
  4expanded class REGULAR_EXPRESSION_BUILDER
  5   --
  6   -- Regular expression building from various dialects.
  7   -- Some REGULAR_EXPRESSION object is build from a string
  8   -- describing a pattern. A regular expression is a pattern
  9   -- that is matched against a subject string.
 10   --
 11   -- See tutorial/regular_expression for usage.
 12   --
 13
 14feature {ANY} -- Building REGULAR_EXPRESSION
 15   convert_posix_pattern (p: STRING): REGULAR_EXPRESSION
 16         -- Create some REGULAR_EXPRESSION from the pattern `p' according to POSIX syntax.
 17         -- If `p' is not a valid regular expression according to POSIX syntax, then `Result' is Void
 18         -- and `last_error_message' and `last_error_position' are set.
 19      require
 20         p /= Void
 21      do
 22         Result := convert_backtracking_pattern(p, posix_builder)
 23      ensure
 24         Result /= Void xor last_error_message /= Void
 25         initialized: Result /= Void implies not Result.last_match_succeeded
 26         substitution_cleared: Result /= Void implies not Result.substitution_pattern_ready
 27      end
 28
 29   convert_perl_pattern (p: STRING): REGULAR_EXPRESSION
 30         -- Create some REGULAR_EXPRESSION from the pattern `p' according to Perl syntax.
 31         -- If `p' is not a valid regular expression according to Perl syntax, then `Result' is Void
 32         -- and `last_error_message' and `last_error_position' are set.
 33      require
 34         p /= Void
 35      do
 36         if has_extended_legibility then
 37            perl5_builder.set_extended_legibility
 38         else
 39            perl5_builder.set_no_extended_legibility
 40         end
 41         Result := convert_backtracking_pattern(p, perl5_builder)
 42      ensure
 43         Result /= Void xor last_error_message /= Void
 44         initialized: Result /= Void implies not Result.last_match_succeeded
 45         substitution_cleared: Result /= Void implies not Result.substitution_pattern_ready
 46      end
 47
 48   convert_python_pattern (p: STRING): REGULAR_EXPRESSION
 49         -- Create some REGULAR_EXPRESSION from the pattern `p' according to Python syntax.
 50         -- If `p' is not a valid regular expression according to Python syntax, then `Result' is Void
 51         -- and `last_error_message' and `last_error_position' are set.
 52      require
 53         p /= Void
 54      do
 55         if has_extended_legibility then
 56            python_builder.set_extended_legibility
 57         else
 58            python_builder.set_no_extended_legibility
 59         end
 60         Result := convert_backtracking_pattern(p, python_builder)
 61      ensure
 62         Result /= Void xor last_error_message /= Void
 63         initialized: Result /= Void implies not Result.last_match_succeeded
 64         substitution_cleared: Result /= Void implies not Result.substitution_pattern_ready
 65      end
 66
 67feature {ANY} -- options
 68   is_case_insensitive: BOOLEAN
 69         -- Is the match case insensitive?
 70         -- Default is False
 71
 72   is_case_sensitive: BOOLEAN
 73         -- Is the match case sensitive?
 74         -- Default is True
 75      do
 76         Result := not is_case_insensitive
 77      end
 78
 79   set_case_sensitive
 80         -- Set the match as case sensitive.
 81      do
 82         is_case_insensitive := False
 83      ensure
 84         definition: is_case_insensitive = False and is_case_sensitive = True
 85      end
 86
 87   set_case_insensitive
 88         -- Set the match as case insensitive.
 89      do
 90         is_case_insensitive := True
 91      ensure
 92         definition: is_case_insensitive = True and is_case_sensitive = False
 93      end
 94
 95   does_any_match_newline: BOOLEAN
 96         -- Does the "any character" mark match a newline?
 97         -- Default is False
 98
 99   set_any_match_newline
100         -- The "any character" mark will match a newline.
101      do
102         does_any_match_newline := True
103      ensure
104         definition: does_any_match_newline = True
105      end
106
107   set_any_dont_match_newline
108         -- The "any character" mark will not match a newline.
109      do
110         does_any_match_newline := False
111      ensure
112         definition: does_any_match_newline = False
113      end
114
115   does_match_line_boundary: BOOLEAN
116         -- Does the begin/end marks match line boundary?
117         -- Default is False
118
119   does_match_text_boundary: BOOLEAN
120         -- Does the begin/end marks match text boundary?
121         -- Default is True
122      do
123         Result := not does_match_line_boundary
124      ensure
125         definition: Result = not does_match_line_boundary
126      end
127
128   set_match_line_boundary
129         -- The begin/end marks will match line boundary.
130      do
131         does_match_line_boundary := True
132      ensure
133         definition: does_match_line_boundary = True and does_match_text_boundary = False
134      end
135
136   set_match_text_boundary
137         -- The begin/end marks will match text boundary.
138      do
139         does_match_line_boundary := False
140      ensure
141         definition: does_match_line_boundary = False and does_match_text_boundary = True
142      end
143
144   has_extended_legibility: BOOLEAN
145         -- Is the extended legibility active?
146
147   has_extended_ligibility: BOOLEAN
148         obsolete
149            "Use `has_extended_legibility' instead."
150         do
151            Result := has_extended_legibility
152         end
153
154   set_extended_legibility
155         -- Activate extended legibility.
156      do
157         has_extended_legibility := True
158      ensure
159         definition: has_extended_legibility = True
160      end
161
162   set_extended_ligibility
163      obsolete
164         "Use `set_extended_legibility' instead."
165      do
166         set_extended_legibility
167      ensure
168         definition: has_extended_legibility = True
169      end
170
171   set_no_extended_legibility
172         -- Deactivate extended legibility.
173      do
174         has_extended_legibility := False
175      ensure
176         definition: has_extended_legibility = False
177      end
178
179   set_no_extended_ligibility
180      obsolete
181         "Use `set_no_extended_legibility' instead."
182      do
183         set_no_extended_legibility
184      ensure
185         definition: has_extended_legibility = False
186      end
187
188   set_default_options
189         -- Set the default options
190      do
191         set_case_sensitive
192         set_any_dont_match_newline
193         set_match_text_boundary
194         set_no_extended_legibility
195      ensure
196         is_case_sensitive
197         not does_any_match_newline
198         does_match_text_boundary
199         not has_extended_legibility
200      end
201
202feature {ANY} -- Error informations
203   last_error_message: STRING
204         -- Used to report error during last creation attempt.
205         --
206         -- See also `convert_perl_pattern', `convert_posix_pattern'.
207
208   last_error_position: INTEGER
209         -- Used to report error position during last creation attempt.
210         --
211         -- See also `convert_perl_pattern', `convert_posix_pattern'.
212
213feature {} -- Internal
214   posix_builder: POSIX_REGULAR_EXPRESSION_BUILDER
215         -- The builder for the POSIX syntax
216      once
217         create Result.make
218      end
219
220   perl5_builder: PERL5_REGULAR_EXPRESSION_BUILDER
221         -- The builder for the PERL5 syntax
222      once
223         create Result.make
224      end
225
226   python_builder: PYTHON_REGULAR_EXPRESSION_BUILDER
227         -- The builder for the Python syntax
228      once
229         create Result.make
230      end
231
232   convert_backtracking_pattern (p: STRING; builder: BACKTRACKING_REGULAR_EXPRESSION_BUILDER): BACKTRACKING_REGULAR_EXPRESSION
233         -- Create some BACKTRACKING_REGULAR_EXPRESSION from the pattern `p' according to the syntax
234         -- passed by the given 'builder'.
235         -- If `p' is not a valid regular expression according the said syntax, then `Result' is Void
236         -- and `last_error_message' and `last_error_message' are set.
237      require
238         p /= Void and builder /= Void
239      do
240         if is_case_insensitive then
241            builder.set_case_insensitive
242         else
243            builder.set_case_sensitive
244         end
245         if does_any_match_newline then
246            builder.set_any_match_newline
247         else
248            builder.set_any_dont_match_newline
249         end
250         if does_match_line_boundary then
251            builder.set_match_line_boundary
252         else
253            builder.set_match_text_boundary
254         end
255         builder.set_expression(p)
256         builder.parse
257         if builder.has_result then
258            create {BACKTRACKING_REGULAR_EXPRESSION} Result.make
259            Result.set_pattern(builder.last_pattern)
260            last_error_message := Void
261         else
262            last_error_position := builder.position
263            last_error_message := builder.last_error.twin
264         end
265      ensure
266         Result /= Void xor last_error_message /= Void
267         initialized: Result /= Void implies not Result.last_match_succeeded
268         substitution_cleared: Result /= Void implies not Result.substitution_pattern_ready
269      end
270
271end -- class REGULAR_EXPRESSION_BUILDER
272--
273-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
274--
275-- Permission is hereby granted, free of charge, to any person obtaining a copy
276-- of this software and associated documentation files (the "Software"), to deal
277-- in the Software without restriction, including without limitation the rights
278-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
279-- copies of the Software, and to permit persons to whom the Software is
280-- furnished to do so, subject to the following conditions:
281--
282-- The above copyright notice and this permission notice shall be included in
283-- all copies or substantial portions of the Software.
284--
285-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
286-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
287-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
288-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
289-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
290-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
291-- THE SOFTWARE.