Add Searchable helper module.

Library/Homebrew/searchable.rb

@@ -0,0 +1,31 @@
+module Searchable
+  def search(string_or_regex, &block)
+    case string_or_regex
+    when Regexp
+      search_regex(string_or_regex, &block)
+    else
+      search_string(string_or_regex.to_str, &block)
+    end
+  end
+
+  private
+
+  def simplify_string(string)
+    string.downcase.gsub(/[^a-z\d]/i, "")
+  end
+
+  def search_regex(regex)
+    select do |*args|
+      args = yield(*args) if block_given?
+      [*args].any? { |arg| arg.match?(regex) }
+    end
+  end
+
+  def search_string(string)
+    simplified_string = simplify_string(string)
+    select do |*args|
+      args = yield(*args) if block_given?
+      [*args].any? { |arg| simplify_string(arg).include?(simplified_string) }
+    end
+  end
+end

Library/Homebrew/test/searchable_spec.rb

@@ -0,0 +1,30 @@
+require "searchable"
+
+describe Searchable do
+  subject { ary.extend(described_class) }
+
+  let(:ary) { ["with-dashes"] }
+
+  describe "#search" do
+    context "when given a block" do
+      let(:ary) { [["with-dashes", "withdashes"]] }
+
+      it "searches by the selected argument" do
+        expect(subject.search(/withdashes/) { |_, short_name| short_name }).not_to be_empty
+        expect(subject.search(/withdashes/) { |long_name, _| long_name }).to be_empty
+      end
+    end
+
+    context "when given a regex" do
+      it "does not simplify strings" do
+        expect(subject.search(/with\-dashes/)).to eq ["with-dashes"]
+      end
+    end
+
+    context "when given a string" do
+      it "simplifies both the query and searched strings" do
+        expect(subject.search("with dashes")).to eq ["with-dashes"]
+      end
+    end
+  end
+end