Class
String
In: lib/rake.rb
Parent: Object

User defined methods to be added to String.

Methods

ext, pathmap, pathmap_explode, pathmap_partial, pathmap_replace,
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:

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 202
202:     def pathmap(spec=nil, &block)
203:       return self if spec.nil?
204:       result = ''
205:       spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
206:         case frag
207:         when '%f'
208:           result << File.basename(self)
209:         when '%n'
210:           result << File.basename(self).ext
211:         when '%d'
212:           result << File.dirname(self)
213:         when '%x'
214:           result << $1 if self =~ /[^\/](\.[^.]+)$/
215:         when '%X'
216:           if self =~ /^(.+[^\/])(\.[^.]+)$/
217:             result << $1
218:           else
219:             result << self
220:           end
221:         when '%p'
222:           result << self
223:         when '%s'
224:           result << (File::ALT_SEPARATOR || File::SEPARATOR)
225:         when '%-'
226:           # do nothing
227:         when '%%'
228:           result << "%"
229:         when /%(-?\d+)d/
230:           result << pathmap_partial($1.to_i)
231:         when /^%\{([^}]*)\}(\d*[dpfnxX])/
232:           patterns, operator = $1, $2
233:           result << pathmap('%' + operator).pathmap_replace(patterns, &block)
234:         when /^%/
235:           fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
236:         else
237:           result << frag
238:         end
239:       end
240:       result
241:     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:       target = File.dirname(self)
107:       dirs = target.pathmap_explode
108:       if n > 0
109:         File.join(dirs[0...n])
110:       elsif n < 0
111:         partial = dirs[n..-1]
112:         if partial.nil? || partial.empty?
113:           target
114:         else
115:           File.join(partial)
116:         end
117:       else
118:         "."
119:       end
120:     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 125
125:     def pathmap_replace(patterns, &block)
126:       result = self
127:       patterns.split(';').each do |pair|
128:         pattern, replacement = pair.split(',')
129:         pattern = Regexp.new(pattern)
130:         if replacement == '*' && block_given?
131:           result = result.sub(pattern, &block)
132:         elsif replacement
133:           result = result.sub(pattern, replacement)
134:         else
135:           result = result.sub(pattern, '')
136:         end
137:       end
138:       result
139:     end