Cleanup exceptions

lib/ClosedException.php

@@ -2,4 +2,4 @@
 
 namespace Amp\ByteStream;
 
-class ClosedException extends \Exception {}
+class ClosedException extends StreamException {}

lib/Internal/functions.php

@@ -2,14 +2,14 @@
 
 namespace Amp\ByteStream\Internal;
 
-use Amp\ByteStream\{ ReadableStream, WritableStream };
+use Amp\ByteStream\{ ReadableStream, StreamException, WritableStream };
 
 /**
  * @internal
  */
 function pipe(ReadableStream $source, WritableStream $destination, int $bytes = null): \Generator {
     if (!$destination->isWritable()) {
-        throw new \LogicException("The destination is not writable");
+        throw new StreamException("The destination is not writable");
     }
 
     if (null !== $bytes) {
@@ -24,7 +24,7 @@ function pipe(ReadableStream $source, WritableStream $destination, int $bytes =
         $written += yield $destination->write(
             yield $source->read()
         );
-    } while ($source->isReadable() && $destination->isWritable());
+    } while ($source->isReadable());
 
     return $written;
 }

lib/MemoryStream.php

@@ -77,11 +77,11 @@ class MemoryStream implements DuplexStream {
 
     private function fetch(int $bytes = null, string $delimiter = null): Promise {
         if ($bytes !== null && $bytes <= 0) {
-            throw new \InvalidArgumentException("The number of bytes to read should be a positive integer or null");
+            throw new \Error("The number of bytes to read should be a positive integer or null");
         }
     
         if (!$this->readable) {
-            return new Failure(new \LogicException("The stream has been closed"));
+            return new Failure(new StreamException("The stream is not readable"));
         }
         
         $deferred = new Deferred;
@@ -153,7 +153,7 @@ class MemoryStream implements DuplexStream {
      */
     protected function send(string $data, bool $end = false): Promise {
         if (!$this->writable) {
-            return new Failure(new \LogicException("The stream is not writable"));
+            return new Failure(new StreamException("The stream is not writable"));
         }
         
         if ($end) {

lib/StreamException.php

@@ -0,0 +1,5 @@
+<?php
+
+namespace Amp\ByteStream;
+
+class StreamException extends \Exception {}