p.rb

gistfile1.txt

commit 1b7d0c1b7ea0c44ec27df33d72306fd9655fa2bb
Author: Paulo Köch <[email protected]>
Date:   Mon May 13 10:23:18 2019 +0200

    Introduce P

diff --git a/app/lib/p.rb b/app/lib/p.rb
new file mode 100644
index 0000000..4f31a50
--- /dev/null
+++ b/app/lib/p.rb
@@ -0,0 +1,54 @@
+module P
+  class PartialApplier < BasicObject
+    def initialize(target)
+      @target = target
+    end
+
+    def respond_to_missing?(method_name, include_private = false)
+      true
+    end
+
+    def method_missing(name, *args, &blk) # rubocop:disable Style/MethodMissingSuper
+      args.unshift(::P) unless args.include? ::P
+      i = args.index(::P)
+      make_args = ->(o) {
+        args.dup.tap { |a| a.delete_at(i) }.insert(i, o)
+      }
+      ->(o) do
+        target.method(name).call(*make_args[o], &blk)
+      end
+    end
+  end
+
+  module ModulesAndClasses
+    def partial_applier
+      PartialApplier.new(self)
+    end
+
+    alias P partial_applier
+  end
+
+  module NiceShorts
+    def respond_to_missing?(method_name, include_private = false)
+      true
+    end
+
+    def method_missing(name, *args, &blk) # rubocop:disable Style/MethodMissingSuper
+      ->(o) { o.method(name)[*args, &blk] }
+    end
+  end
+
+  extend NiceShorts
+
+  unless Module.method_defined? :P
+    Module.include ModulesAndClasses
+  end
+
+  unless Class.method_defined? :P
+    Class.include ModulesAndClasses
+  end
+
+  unless Object.method_defined? :P
+    Object.include ModulesAndClasses
+  end
+end
diff --git a/test/lib/p_test.rb b/test/lib/p_test.rb
new file mode 100644
index 0000000..7df2fe7
--- /dev/null
+++ b/test/lib/p_test.rb
@@ -0,0 +1,27 @@
+# works?
+require "test_helper"
+
+P.load
+
+class PTest < ActiveSupport::TestCase
+  def example(left, right)
+    [left, right].join(" ")
+  end
+
+  test "api" do
+    io = StringIO.new
+
+    __FILE__.then(&(
+      File.P.open("rb")
+      .>> P.read
+      .>> P.split("\n")
+      .>> P.map(&:upcase)
+      .>> P.first
+      .>> P[/([A-Z]+)/, 1]
+      .>> self.P.example("it", P)
+      .>> io.P.write
+    ))
+
+    assert_equal "it WORKS", io.string
+  end
+end