DoubleLinkedList: more tests.

spec/test-lists.cr

@@ -49,9 +49,56 @@ describe "DoubleLinkedList" do
 		list.size.should eq 0
 	end
 
+	it "insert_at" do
+		list = DoubleLinkedList(Int32).new
+		list.insert_at 2, 0
+		list.insert_at 1, 0
+		list.insert_at 3, 2
+		list.insert_at 0, 0
+		list.to_s.should eq "[ 0, 1, 2, 3 ]"
+	end
+
 	it "reverse" do
 		list = DoubleLinkedList(Int32).new
+		list.reverse.to_s.should eq "[  ]"
 		list << 1 << 2 << 3 << 4
 		list.reverse.to_s.should eq "[ 4, 3, 2, 1 ]"
 	end
+
+	it "concat" do
+		list1 = DoubleLinkedList(Int32).new
+		list2 = DoubleLinkedList(Int32).new
+		list1 << 1 << 2
+		list2 << 3 << 4
+		list1.concat list2
+		list1.to_s.should eq "[ 1, 2, 3, 4 ]"
+	end
+
+	it "+" do
+		list1 = DoubleLinkedList(Int32).new
+		list2 = DoubleLinkedList(Int32).new
+		list1 << 1 << 2
+		list2 << 3 << 4
+		list3 = list1 + list2
+		list1.to_s.should eq "[ 1, 2 ]"
+		list2.to_s.should eq "[ 3, 4 ]"
+		list3.to_s.should eq "[ 1, 2, 3, 4 ]"
+	end
+
+	it "shift" do
+		list = DoubleLinkedList(Int32).new
+		list << 1 << 2 << 3 << 4
+		list.shift.value.should eq 1
+		list.shift.value.should eq 2
+		list.shift.value.should eq 3
+		list.shift.value.should eq 4
+	end
+
+	it "peek" do
+		list = DoubleLinkedList(Int32).new
+		list << 1 << 2 << 3 << 4
+		list.peek.value.should eq 4
+		list.pop
+		list.peek.value.should eq 3
+	end
 end

src/list.cr

@@ -42,9 +42,9 @@ class DoubleLinkedList(V)
 	class BrokenList < ::Exception
 	end
 
-	@first : Node(V) | Nil
-	@last : Node(V) | Nil
-	@size : UInt32 = 0
+	property first : Node(V) | Nil
+	property last : Node(V) | Nil
+	property size : UInt32 = 0
 
 	include Enumerable(V | Nil)
 
@@ -94,7 +94,7 @@ class DoubleLinkedList(V)
 	# list = DoubleLinkedList(Int32).new
 	# list << 1            # -> [1]
 	# list << 2            # -> [1] [2]
-	# list.insert_at(3, 1) # [1] [3] [2]
+	# list.insert_at(3, 1) # -> [1] [3] [2]
 	# ```
 	# WARNING: this operation is slow, at worst O(n).
 	def insert_at(value : V, index : Int32) : Node(V)
@@ -196,7 +196,7 @@ class DoubleLinkedList(V)
 	# list = DoubleLinkedList(Int32).new
 	# list << 1
 	# list << 2
-	# list.shift() # -> 1
+	# list.shift # -> 1
 	# ```
 	def shift : Node(V)
 		if first = @first
@@ -213,7 +213,7 @@ class DoubleLinkedList(V)
 	# ```
 	# list = DoubleLinkedList(Int32).new(1)
 	# list << 2
-	# list.peek() # => 2
+	# list.peek # => 2
 	# ```
 	def peek : Node(V)
 		if last = @last
@@ -388,15 +388,12 @@ class DoubleLinkedList(V)
 	# Fancy print of the list's content.
 	def to_s(io)
 		io << "[ "
-
 		remaining_values = @size
-
 		each do |value|
 			io << value
 			remaining_values -= 1
 			io << ", " unless remaining_values == 0
 		end
-
 		io << " ]"
 	end
 end