User defined methods to be added to String.

Methods
Public Instance methods
ext(newext='')

Replace the file extension with newext. If there is no extenson on the string, append the new extension to the end. If the new extension is not given, or is the empty string, remove any existing extension.

ext is a user added method for the String class.

    # File lib/rake.rb, line 82
82:     def ext(newext='')
83:       return self.dup if ['.', '..'].include? self
84:       if newext != ''
85:         newext = (newext =~ /^\./) ? newext : ("." + newext)
86:       end
87:       dup.sub!(%r(([^/\\])\.[^./\\]*$)) { $1 + newext } || self + newext
88:     end
pathmap(spec=nil, &block)

Map the path according to the given specification. The specification controls the details of the mapping. The following special patterns are recognized:

  • %p — The complete path.
  • %f — The base file name of the path, with its file extension, but without any directories.
  • %n — The file name of the path without its file extension.
  • %d — The directory list of the path.
  • %x — The file extension of the path. An empty string if there is no extension.
  • %X — Everything but the file extension.
  • %s — The alternate file separater if defined, otherwise use the standard file separator.
  • %% — A percent sign.

The %d specifier can also have a numeric prefix (e.g. ’%2d’). If the number is positive, only return (up to) n directories in the path, starting from the left hand side. If n is negative, return (up to) |n| directories from the right hand side of the path.

Examples:

  'a/b/c/d/file.txt'.pathmap("%2d")   => 'a/b'
  'a/b/c/d/file.txt'.pathmap("%-2d")  => 'c/d'

Also the %d, %p, $f, $n, %x, and %X operators can take a pattern/replacement argument to perform simple string substititions on a particular part of the path. The pattern and replacement are speparated by a comma and are enclosed by curly braces. The replacement spec comes after the % character but before the operator letter. (e.g. "%{old,new}d"). Muliple replacement specs should be separated by semi-colons (e.g. "%{old,new;src,bin}d").

Regular expressions may be used for the pattern, and back refs may be used in the replacement text. Curly braces, commas and semi-colons are excluded from both the pattern and replacement text (let‘s keep parsing reasonable).

For example:

   "src/org/onestepback/proj/A.java".pathmap("%{^src,bin}X.class")

returns:

   "bin/org/onestepback/proj/A.class"

If the replacement text is ’*’, then a block may be provided to perform some arbitrary calculation for the replacement.

For example:

  "/path/to/file.TXT".pathmap("%X%{.*,*}x") { |ext|
     ext.downcase
  }

Returns:

 "/path/to/file.txt"
     # File lib/rake.rb, line 198
198:     def pathmap(spec=nil, &block)
199:       return self if spec.nil?
200:       result = ''
201:       spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
202:         case frag
203:         when '%f'
204:           result << File.basename(self)
205:         when '%n'
206:           result << File.basename(self).ext
207:         when '%d'
208:           result << File.dirname(self)
209:         when '%x'
210:           result << $1 if self =~ /[^\/](\.[^.]+)$/
211:         when '%X'
212:           if self =~ /^(.*[^\/])(\.[^.]+)$/
213:             result << $1
214:           else
215:             result << self
216:           end
217:         when '%p'
218:           result << self
219:         when '%s'
220:           result << (File::ALT_SEPARATOR || File::SEPARATOR)
221:         when '%-'
222:           # do nothing
223:         when '%%'
224:           result << "%"
225:         when /%(-?\d+)d/
226:           result << pathmap_partial($1.to_i)
227:         when /^%\{([^}]*)\}(\d*[dpfnxX])/
228:           patterns, operator = $1, $2
229:           result << pathmap('%' + operator).pathmap_replace(patterns, &block)
230:         when /^%/
231:           fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
232:         else
233:           result << frag
234:         end
235:       end
236:       result
237:     end
pathmap_explode()

Explode a path into individual components. Used by pathmap.

    # File lib/rake.rb, line 93
93:     def pathmap_explode
94:       head, tail = File.split(self)
95:       return [self] if head == self
96:       return [tail] if head == '.' || tail == '/'
97:       return [head, tail] if head == '/'
98:       return head.pathmap_explode + [tail]
99:     end
pathmap_partial(n)

Extract a partial path from the path. Include n directories from the front end (left hand side) if n is positive. Include |n| directories from the back end (right hand side) if n is negative.

     # File lib/rake.rb, line 105
105:     def pathmap_partial(n)
106:       dirs = File.dirname(self).pathmap_explode
107:       partial_dirs =
108:         if n > 0
109:           dirs[0...n]
110:         elsif n < 0
111:           dirs.reverse[0...-n].reverse
112:         else
113:           "."
114:         end
115:       File.join(partial_dirs)
116:     end
pathmap_replace(patterns, &block)

Preform the pathmap replacement operations on the given path. The patterns take the form ‘pat1,rep1;pat2,rep2…’.

     # File lib/rake.rb, line 121
121:     def pathmap_replace(patterns, &block)
122:       result = self
123:       patterns.split(';').each do |pair|
124:         pattern, replacement = pair.split(',')
125:         pattern = Regexp.new(pattern)
126:         if replacement == '*' && block_given?
127:           result = result.sub(pattern, &block)
128:         elsif replacement
129:           result = result.sub(pattern, replacement)
130:         else
131:           result = result.sub(pattern, '')
132:         end
133:       end
134:       result
135:     end