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

Rake extension methods for 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 extension 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/ext/string.rb, line 11
11:     def ext(newext='')
12:       return self.dup if ['.', '..'].include? self
13:       if newext != ''
14:         newext = (newext =~ /^\./) ? newext : ("." + newext)
15:       end
16:       self.chomp(File.extname(self)) << newext
17:     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/ext/string.rb, line 127
127:     def pathmap(spec=nil, &block)
128:       return self if spec.nil?
129:       result = ''
130:       spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
131:         case frag
132:         when '%f'
133:           result << File.basename(self)
134:         when '%n'
135:           result << File.basename(self).ext
136:         when '%d'
137:           result << File.dirname(self)
138:         when '%x'
139:           result << File.extname(self)
140:         when '%X'
141:           result << self.ext
142:         when '%p'
143:           result << self
144:         when '%s'
145:           result << (File::ALT_SEPARATOR || File::SEPARATOR)
146:         when '%-'
147:           # do nothing
148:         when '%%'
149:           result << "%"
150:         when /%(-?\d+)d/
151:           result << pathmap_partial($1.to_i)
152:         when /^%\{([^}]*)\}(\d*[dpfnxX])/
153:           patterns, operator = $1, $2
154:           result << pathmap('%' + operator).pathmap_replace(patterns, &block)
155:         when /^%/
156:           fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
157:         else
158:           result << frag
159:         end
160:       end
161:       result
162:     end
pathmap_explode()

Explode a path into individual components. Used by pathmap.

    # File lib/rake/ext/string.rb, line 22
22:     def pathmap_explode
23:       head, tail = File.split(self)
24:       return [self] if head == self
25:       return [tail] if head == '.' || tail == '/'
26:       return [head, tail] if head == '/'
27:       return head.pathmap_explode + [tail]
28:     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/ext/string.rb, line 34
34:     def pathmap_partial(n)
35:       dirs = File.dirname(self).pathmap_explode
36:       partial_dirs =
37:         if n > 0
38:           dirs[0...n]
39:         elsif n < 0
40:           dirs.reverse[0...-n].reverse
41:         else
42:           "."
43:         end
44:       File.join(partial_dirs)
45:     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/ext/string.rb, line 50
50:     def pathmap_replace(patterns, &block)
51:       result = self
52:       patterns.split(';').each do |pair|
53:         pattern, replacement = pair.split(',')
54:         pattern = Regexp.new(pattern)
55:         if replacement == '*' && block_given?
56:           result = result.sub(pattern, &block)
57:         elsif replacement
58:           result = result.sub(pattern, replacement)
59:         else
60:           result = result.sub(pattern, '')
61:         end
62:       end
63:       result
64:     end