diff --git a/core-lib/Collections.ns b/core-lib/Collections.ns
index 12ba94b2e..954a8e36a 100644
--- a/core-lib/Collections.ns
+++ b/core-lib/Collections.ns
@@ -129,6 +129,10 @@ class Collections usingKernel: kernel = Value (
     public removeAll = (
       items removeAll
     )
+
+    public asArray = (
+      ^ items asArray
+    )
   ) : (
     public new = ( ^ self new: initialSize )
   )
@@ -138,6 +142,16 @@ class Collections usingKernel: kernel = Value (
       items do: [ :it | it == anObject ifTrue: [ ^ true ] ].
       ^ false
     )
+
+    public remove: anObject = (
+      | newItems |
+      newItems:: Vector new.
+      [ items isEmpty ]
+        whileFalse: [ | it |
+          it:: items remove.
+          it == anObject ifFalse: [ newItems append: it ] ].
+      items:: newItems
+    )
   ) : (
     public new = ( ^ self new: initialSize )
   )
@@ -236,6 +250,41 @@ class Collections usingKernel: kernel = Value (
         current:: current next ]
     )
 
+    public remove: aKey = (
+      ^ remove: aKey ifAbsent: nil
+    )
+
+    public remove: aKey ifAbsent: aBlock = (
+      | hash i current |
+      hash:: hash: aKey.
+      i:: bucketIdx: hash.
+      current:: buckets at: i.
+
+      current isNil
+        ifTrue: [ ^ aBlock value ]
+        ifFalse: [
+          ^ removeBucketEntry: aKey hash: hash idx: i head: current ifAbsent: aBlock ]
+    )
+
+    private removeBucketEntry: key hash: hash idx: i head: head ifAbsent: aBlock = (
+      | current prev |
+      current:: head.
+
+      [true] whileTrue: [
+        (current match: hash key: key) ifTrue: [
+          prev isNil
+            ifTrue: [ buckets at: i put: current next ]
+            ifFalse: [ prev next: current next ].
+          size_:: size_ - 1.
+          ^ current value ].
+
+        current next isNil ifTrue: [
+          ^ aBlock value ].
+
+        prev:: current.
+        current:: current next ]
+    )
+
     private resize = (
       | oldStorage |
       oldStorage:: buckets.
diff --git a/core-lib/Kernel.ns b/core-lib/Kernel.ns
index 4b730bb02..31db3201c 100644
--- a/core-lib/Kernel.ns
+++ b/core-lib/Kernel.ns
@@ -512,6 +512,38 @@ class Kernel vmMirror: vmMirror = Object <: Value (
       self doIndexes: [ :i | result at: i put: (aBlock value: (self at: i)) ].
       ^ result
     )
+
+    public prependedWith: val = (
+      | result |
+      result:: Array new: self size + 1.
+      self doIndexes: [:i |
+        result at: i + 1 put: (self at: i)].
+      result at: 1 put: val.
+      ^ result
+    )
+
+    public extendedWith: val = (
+      | result |
+      result:: Array new: self size + 1.
+      self doIndexes: [:i |
+        result at: i put: (self at: i)].
+      result at: result size put: val.
+      ^ result
+    )
+
+    public join: joiner = (
+      | result first |
+      first:: true.
+
+      self do: [:e |
+        first
+          ifTrue: [
+            result:: e.
+            first:: false ]
+          ifFalse: [
+            result:: result + joiner + e ] ].
+      ^ result
+    )
   )
 
   public class Array = Object <: ArrayReadMixin ()
diff --git a/core-lib/TestSuite/CollectionTests.ns b/core-lib/TestSuite/CollectionTests.ns
index f8353c92f..606c15138 100644
--- a/core-lib/TestSuite/CollectionTests.ns
+++ b/core-lib/TestSuite/CollectionTests.ns
@@ -305,6 +305,65 @@ class CollectionTests usingPlatform: platform testFramework: minitest = (
       self assert: (c contains: #b).
       self assert: (c contains: #c).
     )
+
+    public testPrependedWith = (
+      | arr result |
+      arr:: Array new: 0.
+      result:: arr prependedWith: 0.
+
+      assert: 1 equals: result size.
+      assert: 0 equals: (result at: 1).
+
+      arr:: Array with: 1 with: 2.
+      result:: arr prependedWith: 0.
+
+      assert: 3 equals: result size.
+      assert: 0 equals: (result at: 1).
+      assert: 1 equals: (result at: 2).
+      assert: 2 equals: (result at: 3).
+    )
+
+    public testExtendedWith = (
+      | arr result |
+      arr:: Array new: 0.
+      result:: arr extendedWith: 0.
+
+      assert: 1 equals: result size.
+      assert: 0 equals: (result at: 1).
+
+      arr:: Array with: 1 with: 2.
+      result:: arr extendedWith: 3.
+
+      assert: 3 equals: result size.
+      assert: 1 equals: (result at: 1).
+      assert: 2 equals: (result at: 2).
+      assert: 3 equals: (result at: 3).
+    )
+
+    public testAsArray = (
+      | set result |
+      set:: Set new.
+      10 to: 110 do: [:i |
+        set add: i].
+
+      result:: set asArray.
+      self assert: 101 equals: set size.
+
+      10 to: 110 do: [:i |
+        self assert: i equals: (result at: i - 9) ]
+    )
+
+    public testJoin = (
+      | arr |
+      arr:: Array new: 0.
+      self assert: nil is: (arr join: ', ').
+
+      arr:: Array with: 1 with: 10 with: 100.
+      self assert: 1 + 20000 + 10 + 20000 + 100 equals: (arr join: 20000).
+
+      arr:: Array with: 'a' with: 'b' with: 'c'.
+      self assert: 'a, b, c' equals: (arr join: ', ').
+    )
   ) : ( TEST_CONTEXT = () )
 
   public class VectorTest = TestContext (
@@ -429,6 +488,31 @@ class CollectionTests usingPlatform: platform testFramework: minitest = (
       self assert: (dict values contains: 55).
     )
 
+    public testRemoveOneByOne = (
+      | dict result |
+      dict:: Dictionary new.
+
+      self assert: dict size equals: 0 description: 'Empty after creation'.
+
+      dict at: #ee put: 5.
+      dict at: #e1 put: 66.
+      dict at: #e2 put: 444.
+
+      self assert: dict size equals: 3 description: 'After inserting 3 elements'.
+
+      self assert: 66 equals: (dict remove: #e1).
+      self assert: dict size equals: 2.
+      self assert: nil is: (dict remove: #e1).
+
+      self assert: 5 equals: (dict remove: #ee).
+      self assert: nil is: (dict remove: #ee).
+      self assert: dict size equals: 1.
+
+      self assert: 444 equals: (dict remove: #e2).
+      self assert: nil is: (dict remove: #e2).
+      self assert: dict size equals: 0.
+    )
+
     public testRemoveAll = (
       | dict |
       dict:: Dictionary new.
diff --git a/src/som/compiler/Parser.java b/src/som/compiler/Parser.java
index 960b3c2f9..bc61cf258 100644
--- a/src/som/compiler/Parser.java
+++ b/src/som/compiler/Parser.java
@@ -1402,7 +1402,15 @@ private ExpressionNode binaryOperand(final MethodBuilder builder)
       evenutalSend = accept(EventualSend, KeywordTag.class);
     }
 
-    assert !evenutalSend : "eventualSend should not be true, because that means we steal it from the next operation (think here shouldn't be one, but still...)";
+    if (evenutalSend) {
+      // eventualSend should not be true, because that means we steal it from the next
+      // operation (think here shouldn't be one, but still...)
+      throw new ParseError(
+          "Parsing something unexpectedly as eventual send. " +
+              "Perhaps some variable declaration statement is not terminated?",
+          Symbol.NONE, this);
+    }
+
     return operand;
   }
 
diff --git a/tests/dym/expected-results.tar.bz2 b/tests/dym/expected-results.tar.bz2
index 77af9dd07..b1d46bde7 100644
Binary files a/tests/dym/expected-results.tar.bz2 and b/tests/dym/expected-results.tar.bz2 differ