resource

Type Members

1. type CloseResult = Result[CloseError, Unit]

   

2. trait Closeable[A] extends AnyRef

   

   Type class for all types that can be closed.

3. type InputResource[A] = Resource[A, InputStream]

   

   Resource specialised for java.io.InputStream.

4. type OpenResult[A] = Result[OpenError, A]

   

5. type OutputResource[A] = Resource[A, OutputStream]

   

   Resource specialised for java.io.OutputStream.

6. type ProcessResult[A] = Result[ProcessError, A]

   

7. type ReaderResource[A] = Resource[A, Reader]

   

   Resource specialised for java.io.Reader.

   Resource specialised for java.io.Reader.

   Note that it's good practice not to declare explicit instances of ReaderResource for types that have an instance of InputResource. It's better to let the implicit resolution mechanism work out how to best turn an InputStream into a Reader - the kantan.codecs.resource.bom package, in particular, relies on this.

8. trait Resource[I, R] extends AnyRef

   

   Represents a resource that can be opened and worked on.

   Represents a resource that can be opened and worked on.

   The purpose of this trait is to abstract over the notion of "things that can be opened", such as files, URLs... Default instances are provided for java.io types - java.io.File, for example, has instances for both opening it for reading and for writing.

   I

   type of the resource itself (eg java.io.File).

   R

   type of the opened resource (eg java.io.InputStream)

9. sealed trait ResourceError extends Product with Serializable

   

10. trait ResourceIterator[+A] extends TraversableOnce[A] with java.io.Closeable

    

    Offers iterator-like access to IO resources.

    Offers iterator-like access to IO resources.

    For the most part, values of type ResourceIterator can be considered as iterators, with a few improvements.

    First, they have a ResourceIterator.close()* method, which allows you to release the underlying resource when needed. This is fairly important and part of the reason why working with Source.getLines can be so aggravating.

    Second, ResourceIterator.close()* is mostly not needed: whenever an IO error occurs or the underlying resource is empty, it will be closed automatically. Provided you intend to read the whole resource, you never need to explicitly close it. This covers non-obvious cases such as filtering or dropping elements.

    You should be able to express most common causes for not reading the entire stream through standard combinators. For example, "take the first n elements" is take(n), or "take all odd elements" is filter(_ % 2 == 0). This allows you to ignore the fact that the underlying resource needs to be closed. Should you ever find youself in a situation when you just want to stop, however, ResourceIterator.close()* is available.

    Annotations

    @SuppressWarnings()

11. type ResourceResult[A] = Result[ResourceError, A]

    

12. type WriterResource[A] = Resource[A, Writer]

    

    Resource specialised for java.io.Writer.

    Resource specialised for java.io.Writer.

    Note that it's good practice not to declare explicit instances of WriterResource for types that have an instance of OutputResource. It's better to let the implicit resolution mechanism work out how to best turn an OutputStream into a Writer - the kantan.codecs.resource.bom package, in particular, relies on this.