Add `PATH` class.

1 files changed, 61 insertions, 0 deletions

diff --git a/Library/Homebrew/PATH.rb b/Library/Homebrew/PATH.rb
new file mode 100644
index 000000000..d6b549a1e
--- /dev/null
+++ b/Library/Homebrew/PATH.rb
@@ -0,0 +1,61 @@
+class PATH
+  def initialize(*paths)
+    @paths = parse(*paths)
+  end
+
+  def prepend(*paths)
+    @paths.unshift(*parse(*paths))
+    self
+  end
+
+  def append(*paths)
+    @paths.concat(parse(*paths))
+    self
+  end
+
+  def to_ary
+    @paths
+  end
+  alias to_a to_ary
+
+  def to_str
+    @paths.join(File::PATH_SEPARATOR)
+  end
+  alias to_s to_str
+
+  def eql?(other)
+    if other.respond_to?(:to_ary)
+      return true if to_ary == other.to_ary
+    end
+
+    if other.respond_to?(:to_str)
+      return true if to_str == other.to_str
+    end
+
+    false
+  end
+  alias == eql?
+
+  def empty?
+    @paths.empty?
+  end
+
+  def inspect
+    "<PATH##{to_str}>"
+  end
+
+  def validate
+    self.class.new(@paths.select(&File.method(:directory?)))
+  end
+
+  private
+
+  def parse(*paths)
+    paths
+      .flatten
+      .flat_map { |p| p.respond_to?(:to_str) ? p.to_str.split(File::PATH_SEPARATOR): p }
+      .compact
+      .map { |p| p.respond_to?(:to_path) ? p.to_path : p.to_str }
+      .uniq
+  end
+end