import scala.collection._
import scala.collection.immutable.StringLike
import scala.language.higherKinds
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
import scalaz._
+import Scalaz._
object TSV {
- type Header = Seq[Symbol]
- type Field = String
- type Record = Map[Symbol, Field]
-
- // ---
- type Failure[ F[_, _], E, R] = E => F[E, R]
- type Success[A, F[_, _], E, R] = A => F[E, R]
- trait Parser[E, A] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[A, F, E, R]): F[E, R]
- }
-
- implicit def ParserFunctor[E] = new Functor[({type λ[α] = Parser[E, α]})#λ] {
- def map[A, B](m: Parser[E, A])(f: A => B) = new Parser[E, B] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[B, F, E, R]): F[E, R] = {
+ implicit val ParserFunctor = new Functor[Parser] {
+ def map[A, B](m: Parser[A])(f: A => B) = new Parser[B] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[B, F, R]): F[R] = {
def ks_(a: A) = ks(f(a))
return m.runParser(kf, ks_)
}
}
}
- implicit def ParserApplicative[E] = new Applicative[({type λ[α] = Parser[E, α]})#λ] {
- def point[A](a: => A) = new Parser[E, A] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[A, F, E, R]): F[E, R]
+ implicit val ParserApplicative = new Applicative[Parser] {
+ def point[A](a: => A) = new Parser[A] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[A, F, R]): F[R]
= ks(a)
}
- def ap[A, B](m: => Parser[E, A])(fm: => Parser[E, A => B]) = new Parser[E, B] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[B, F, E, R]): F[E, R] = {
- def ks_(f: A => B): F[E, R] = {
+ def ap[A, B](m: => Parser[A])(fm: => Parser[A => B]) = new Parser[B] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[B, F, R]): F[R] = {
+ def ks_(f: A => B): F[R] = {
def ks__(a: A) = ks(f(a))
return m.runParser(kf, ks__)
}
}
}
- implicit def ParserMonad[E] = new Monad[({type λ[α] = Parser[E, α]})#λ] {
- def point[A](a: => A)
- = implicitly[Applicative[({type λ[α] = Parser[E, α]})#λ]].point(a)
+ implicit val ParserMonad = new Monad[Parser] {
+ def point[A](a: => A) = a.point[Parser]
- def bind[A, B](m: Parser[E, A])(f: A => Parser[E, B]) = new Parser[E, B] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[B, F, E, R]): F[E, R] = {
+ def bind[A, B](m: Parser[A])(f: A => Parser[B]) = new Parser[B] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[B, F, R]): F[R] = {
def ks_(a: A) = f(a).runParser(kf, ks)
return m.runParser(kf, ks_)
}
}
}
- implicit def ParserMonadError[E] = new MonadError[Parser, E] {
- def point[A](a: => A)
- = implicitly[Applicative[({type λ[α] = Parser[E, α]})#λ]].point(a)
-
- def bind[A, B](m: Parser[E, A])(f: A => Parser[E, B])
- = implicitly[Monad[({type λ[α] = Parser[E, α]})#λ]].bind(m)(f)
+ implicit val ParserMonadError = new MonadError[({type λ[String, α] = Parser[α]})#λ, String] {
+ def point[A](a: => A) = a.point[Parser]
+ def bind[A, B](m: Parser[A])(f: A => Parser[B]) = m.flatMap(f)
- def handleError[A](m: Parser[E, A])(f: E => Parser[E, A]) = new Parser[E, A] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[A, F, E, R]): F[E, R] = {
- def kf_(e: E) = f(e).runParser(kf, ks)
+ def handleError[A](m: Parser[A])(f: String => Parser[A]) = new Parser[A] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[A, F, R]): F[R] = {
+ def kf_(e: String) = f(e).runParser(kf, ks)
return m.runParser(kf_, ks)
}
}
- def raiseError[A](e: E) = new Parser[E, A] {
- def runParser[F[_, _], R](kf: Failure[F, E, R], ks: Success[A, F, E, R]): F[E, R]
+ def raiseError[A](e: String) = new Parser[A] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[A, F, R]): F[R]
= kf(e)
}
}
- def runParser[E, A](p: Parser[E, A]): Either[E, A] = {
- def left (e: E): Either[E, A] = Left(e)
- def right(x: A): Either[E, A] = Right(x)
- return p.runParser(left, right)
+ implicit def ToMonadErrorOps[A](m: Parser[A]) = new {
+ def handleError(f: String => Parser[A]): Parser[A]
+ = implicitly[MonadError[({type λ[String, α] = Parser[α]})#λ, String]].handleError(m)(f)
}
- // ---
- def decode[A: FromRecord](tsv: StringLike[_]): Seq[A] = {
- val lines = tsv.split('\n').filter(!_.isEmpty)
- val header = lines.head.split('\t').map(Symbol(_))
- val body = lines.tail.map(line => (header zip line.split('\t')).toMap)
- return body.map(implicitly[FromRecord[A]].parseRecord)
+ implicit def ToMonadErrorIdOps(e: String) = new {
+ def raiseError[A]: Parser[A]
+ = implicitly[MonadError[({type λ[String, α] = Parser[α]})#λ, String]].raiseError(e)
+ }
+
+ type Header = Seq[Symbol]
+
+ case class Field(value: String) {
+ def parseField[A: FromField]
+ = implicitly[FromField[A]].parseField(Field(value))
+ }
+
+ case class Record(value: Map[Symbol, Field]) {
+ def parseRecord[A: FromRecord]
+ = implicitly[FromRecord[A]].parseRecord(Record(value))
+
+ def lookup[A: FromField](name: Symbol): Parser[A]
+ = value.get(name).fold(("no field named " + name.name).raiseError[A])(_.parseField[A])
+ }
+
+ type Failure[ F[_], R] = String => F[R]
+ type Success[A, F[_], R] = A => F[R]
+
+ trait Parser[+A] {
+ def runParser[F[_], R](kf: Failure[F, R], ks: Success[A, F, R]): F[R]
+ }
+
+ def runParser[A](p: Parser[A]): Either[String, A] = {
+ type F[R] = Either[String, R]
+ def left (e: String): F[A] = Left(e)
+ def right(x: A ): F[A] = Right(x)
+ return p.runParser(left, right)
}
trait FromRecord[A] {
- def parseRecord(r: Record): A
+ def parseRecord(r: Record): Parser[A]
}
trait FromField[A] {
- def parseField(f: Field): A
+ def parseField(f: Field): Parser[A]
}
- def parseField[A: FromField](f: Field): A
- = implicitly[FromField[A]].parseField(f)
trait ToRecord[A] {
def toRecord(a: A): Record
def toField(a: A): Field
}
+ class DecodeFailedException private(e: RuntimeException) extends RuntimeException(e) {
+ def this(msg: String) = this(new RuntimeException(msg))
+ def this(msg: String, cause: Throwable) = this(new RuntimeException(msg, cause))
+ }
+
+ def decode[A: FromRecord](tsv: StringLike[_]): Seq[A] = {
+ val lines = tsv.split('\n').filter(!_.isEmpty)
+ val header = lines.head.split('\t').map(Symbol(_))
+ val body = lines.tail.map(line => Record((header zip line.split('\t').map { Field(_) }).toMap))
+ return body.map { r =>
+ runParser(r.parseRecord[A]) match {
+ case Right(a) => a
+ case Left(e) => throw new DecodeFailedException(e)
+ }
+ }
+ }
+
// Option[A]
implicit def OptionFromField[A: FromField] = new FromField[Option[A]] {
- def parseField(f: Field): Option[A] = {
- if (f.isEmpty) {
- return None
+ def parseField(f: Field): Parser[Option[A]] = {
+ if (f.value.isEmpty) {
+ return None.point[Parser]
}
else {
- return Some(implicitly[FromField[A]].parseField(f))
+ f.parseField[A].map { Some(_) }
}
}
}
// String
- implicit def StringFromField = new FromField[String] {
- def parseField(f: Field): String = f
+ implicit val StringFromField = new FromField[String] {
+ def parseField(f: Field): Parser[String] = f.value.point[Parser]
}
// Int
- implicit def IntFromField = new FromField[Int] {
- def parseField(f: Field): Int = f.toInt
+ implicit val IntFromField = new FromField[Int] {
+ def parseField(f: Field): Parser[Int] = {
+ try {
+ f.value.toInt.point[Parser]
+ }
+ catch {
+ case e: NumberFormatException =>
+ e.getMessage().raiseError[Int]
+ }
+ }
}
}
projects / task-reporter.git / blobdiff