stew

scala> List(BigDecimal(1).some, BigDecimal(13).some, BigDecimal(12).some).sequence.map(_.sum)
res14: Option[scala.math.BigDecimal] = Some(26)

scala> List(BigDecimal(1).some, None, BigDecimal(12).some).sequence.map(_.sum)
res15: Option[scala.math.BigDecimal] = None

stew

This tries to find where the Spec/test of the current buffer lives,
and either creates it, or visits it
#+begin_src emacs-lisp
 (defun split-path-of-file (f)
"return dirname.filename" (let ((sp (reverse (split-string f "/"))))
(cons (mapconcat 'identity (reverse (cdr sp)) "/") (car sp))))

(defun scala-test-file-name (f)
  (let* ((sp (reverse (split-string f "\\.")))
	 (h (car sp))

stew

(defun build-package-name (pn d)
  (if (null d)
      pn
    (let ((c (car d)))
      (if (equal c "scala")
	  pn
	(build-package-name (concat c "." pn) (cdr d))))))
 
(defun scala-package-name-from-buffer ()
  (let ((l (reverse (split-string (buffer-file-name) "/"))))

stew

* tags
** load-tags-for-this-project
#+begin_src emacs-lisp
(defun find-file-upwards (file-to-find)
  "Recursively searches each parent directory starting from the default-directory.
looking for a file with name file-to-find.  Returns the path to it
or nil if not found."
  (labels
      ((find-file-r (path)
                    (let* ((parent (file-name-directory path))

stew

scala> import scalaz.syntax.bitraverse._
import scalaz.syntax.bitraverse._

scala> import scalaz.std.tuple._
import scalaz.std.tuple._

scala> (List(1,2,3), List("a")).leftMap(_.map(_ + 1))
res0: (List[Int], List[String]) = (List(2, 3, 4),List(a))

stew

package scalaz.example

object RunLengthEncoder extends App {
  import scalaz._
  import scalaz.std.option._
  import scalaz.std.anyVal._
  import scalaz.syntax.show._
  import scalaz.syntax.apply._

  /*

stew

module natToBin

data Parity : Nat -> Type where
even : Parity (n + n)
odd : Parity (S (n + n))

parity : (n:Nat) -> Parity n

natToBin : Nat -> List Bool
natToBin Z = Nil

stew

module partition

%default total

even : Nat -> Bool
even x = (mod x 2) == 0

partition' : (a -> Bool) -> List a -> List a
partition' f [] = []
partition' f (x :: xs) with (partition' f xs)

stew

import scalaz._
import scalaz.std.list._
import scalaz.syntax.traverse._
import scalaz.State._

trait Main {
  type TypeEnvironment
  case class GetTypeEnvironment(get: TypeEnvironment)
  case class Processor(after: GetTypeEnvironment)
  def performTypeInference(typeEnv: TypeEnvironment, next: Processor): Processor

stew

java.lang.StackOverflowError
        at scalaz.syntax.ShowOps.<init>(ShowSyntax.scala:5)
        at scalaz.syntax.ToShowOps$class.ToShowOps(ShowSyntax.scala:16)
        at scalaz.Scalaz$.ToShowOps(Scalaz.scala:3)
        at scalaz.example.CABRunLengthEncoder$.writeOutput(ReaderWriterStateTUsage.scala:143)
        at scalaz.example.CABRunLengthEncoder$$anonfun$emit$1$$anonfun$apply$7$$anonfun$4.apply(ReaderWriterStateTUsage.scala:154)
        at scalaz.example.CABRunLengthEncoder$$anonfun$emit$1$$anonfun$apply$7$$anonfun$4.apply(ReaderWriterStateTUsage.scala:154)
        at scalaz.std.OptionFunctions$class.cata(Option.scala:179)
        at scalaz.std.option$.cata(Option.scala:231)
        at scalaz.syntax.std.OptionOps.cata(OptionOps.scala:9)