Merge pull request #184 from vigoo/repeated

Repeated modifier

clipp-core/src/main/scala/io/github/vigoo/clipp/clipp.scala

@@ -8,11 +8,13 @@ import io.github.vigoo.clipp.errors.ParserError
 
 /**
  * Type class for parsing a command line argument to type T
+ *
  * @tparam T
  */
 trait ParameterParser[T] {
   /**
    * Parse the command line argument into type T or fail with an error message
+   *
    * @param value command line argument
    * @return Either failure or the parsed value
    */

clipp-core/src/main/scala/io/github/vigoo/clipp/syntax.scala

@@ -57,19 +57,29 @@ trait syntax {
                                     withDocumentedChoices: List[T]): Parameter.Spec[T] =
     liftF(SimpleParameter(placeholder, description, Some(withDocumentedChoices), implicitly))
 
-  def command(validValues: String*): Free[Parameter, String] =
+  def command(validValues: String*): Parameter.Spec[String] =
     liftF(Command(validValues.toList, None))
 
-  def command(validValues: List[String], withDocumentedChoices: List[String]): Free[Parameter, String] =
+  def command(validValues: List[String], withDocumentedChoices: List[String]): Parameter.Spec[String] =
     liftF(Command(validValues, Some(withDocumentedChoices)))
 
-  def optional[T](parameter: Parameter.Spec[T]): Free[Parameter, Option[T]] =
+  def optional[T](parameter: Parameter.Spec[T]): Parameter.Spec[Option[T]] =
     liftF[Parameter, Option[T]](Optional(parameter))
 
-  def metadata(programName: String): Free[Parameter, Unit] =
+  def repeated[T](parameter: Parameter.Spec[T]): Parameter.Spec[List[T]] = {
+    def go(acc: List[T]): Parameter.Spec[List[T]] =
+      optional(parameter).flatMap {
+        case None => pure(acc.reverse)
+        case Some(item) => go(item :: acc)
+      }
+
+    go(List.empty)
+  }
+
+  def metadata(programName: String): Parameter.Spec[Unit] =
     liftF[Parameter, Unit](SetMetadata(ParameterParserMetadata(programName, None)))
 
-  def metadata(programName: String, description: String): Free[Parameter, Unit] =
+  def metadata(programName: String, description: String): Parameter.Spec[Unit] =
     liftF[Parameter, Unit](SetMetadata(ParameterParserMetadata(programName, Some(description))))
 
   def pure[T](value: T): Parameter.Spec[T] =

clipp-core/src/test/scala/io/github/vigoo/clipp/ParserSpecs.scala

@@ -25,6 +25,11 @@ class ParserSpecs extends Specification {
     verbose <- flag("Verbosity", 'v', "verbose")
   } yield (verbose, name, password)
 
+  private val specMultiNamedParams = for {
+    names <- repeated { namedParameter[String]("Name", "name", 'n', "name", "username") }
+    _ <- namedParameter[String]("other", "other", "other")
+  } yield names
+
   private val specMix = for {
     name <- namedParameter[String]("User name", "name", 'u', "name", "username")
     verbose <- flag("Verbosity", 'v', "verbose")
@@ -100,6 +105,12 @@ class ParserSpecs extends Specification {
       )
     }
 
+    "be able to collect multiple named parameters" in {
+      Parser.extractParameters(Seq("--name", "1", "--other", "param", "--username", "2", "-n", "3"), specMultiNamedParams) should beRight(
+        (List("1", "2", "3"))
+      )
+    }
+
     "optional named parameter works" in {
       val spec = for {
         required <- namedParameter[String]("A required parameter", "value", "required")

docs/docs/docs/index.md

@@ -168,6 +168,7 @@ The semantics of these parsing commands are the following:
 - `namedParameter[T]` looks for a `--name value` pair of arguments *before the first command location* (if any), **removes both** from the list of arguments and parses the value with an instance of the `ParameterParser` type class
 - `parameter[T]` takes the first argument that does not start with `-` *before the first command location* (if any) and **removes it from the list of arguments, then parses the value with an instance of the `ParameterParser` type class
 - `optional` makes parser specification section optional
+- `repeated` repeates a parser specification until it fails and collects the results as a list. 
 - `command` is a special parameter with a fix set of values, which is parsed by taking the first argument that does not start with `-` and **it drops all the arguments until the command** from the list of arguments.
 
 The semantics of `command` strongly influences the set of CLI interfaces parseable by this library, but it is