Added insert() and related tests (+ more length checks)

src/nimdeque.nim

@@ -14,6 +14,19 @@
 import private/queues/linked
 
 
-
+# Exports linked queue stuff
 export newLinkedDeque
-export LinkedDeque
+export LinkedDeque
+export add
+export addLeft
+export contains
+export items
+export reversed
+export len
+export linked.high
+export pop
+export `[]`
+export `[]=`
+export pairs
+export linked.`$`
+export insert

src/private/queues/linked.nim

@@ -70,7 +70,7 @@ proc addLeft*[T](self: LinkedDeque[T], val: T) =
     self.head.next = head
     head.prev = node
     inc(self.size)
-    
+
 
 proc len*[T](self: LinkedDeque[T]): int =
     ## Returns the length of the deque.
@@ -111,7 +111,32 @@ proc getNode[T](self: LinkedDeque[T], i: int): DequeNode[T] =
         while pos > i:
             result = result.prev
             dec(pos)
-    
+
+
+
+proc insert*[T](self: LinkedDeque[T], pos: int, val: T) =
+    ## Inserts the given value at the given
+    ## position. When pos equals 0 or self.high(),
+    ## this proc is equivalent to addLeft and add
+    ## respectively. In all other cases, all items
+    ## are "shifted" by 1 (shifted is in quotes because
+    ## no shifting actually occurs, but the result is
+    ## the same). The operation takes constant time
+    if pos == 0:
+        self.addLeft(val)
+    elif pos == self.high():
+        self.add(val)
+    else:
+        var node = self.getNode(pos)
+        var prev: DequeNode[T] = node.prev
+        var newNode = newDequeNode(val)
+        node.prev = newNode
+        prev.next = newNode
+        newNode.next = node
+        newNode.prev = prev
+        inc(self.size)
+
+
 
 proc `[]`*[T](self: LinkedDeque[T], i: int): T =
     ## Implements indexing into the queue
@@ -187,6 +212,6 @@ proc `$`*[T](self: LinkedDeque[T]): string =
     result = "deque(["
     for i, item in self:
         result &= $item
-        if i < self.high():
+        if i < self.len():
             result &= ", "
     result &= "])"

tests/linked.nim

@@ -16,11 +16,13 @@ import ../src/nimdeque
 
 
 when isMainModule:
-    const size = 10000
+    const size = 1000
     var deque = newLinkedDeque[int]()
     echo &"Generating {size} values"
     for i in countup(0, size, 1):
         deque.add(i)
+    echo "Checking length"
+    doAssert deque.len() == size + 1
     echo "Checking iteration"
     for i in countup(0, size, 1):
         doAssert deque[i] == i
@@ -29,8 +31,12 @@ when isMainModule:
         doAssert i in deque
     echo "Popping off the head"
     doAssert deque.pop() == 0
+    echo "Checking length"
+    doAssert deque.len() == size 
     echo "Popping off the tail"
     doAssert deque.pop(deque.high()) == size
+    echo "Checking length"
+    doAssert deque.len() == size - 1
     echo "Checking new head"
     doAssert deque[0] == 1
     echo "Checking new tail"
@@ -38,11 +44,40 @@ when isMainModule:
     echo "Re-checking values"
     for i in countup(0, size - 2, 1):
         doAssert deque[i] == i + 1
-    echo "Appending value at the beginning"
+    echo "Checking addLeft"
     deque.addLeft(0)
+    echo "Checking length"
+    doAssert deque.len() == size
     echo "Re-checking head"
     doAssert deque[0] == 0
     echo "Re-checking values"
     for i in countup(0, size - 1, 1):
         doAssert deque[i] == i
+    echo "Checking insert(3)"
+    var oldLen = deque.len()
+    deque.insert(3, 69420)
+    echo "Checking length"
+    doAssert oldLen + 1 == deque.len()
+    echo "Checking inserted value"
+    doAssert deque.pop(3) == 69420
+    echo "Checking length"
+    doAssert deque.len() == oldLen
+    echo &"Checking insert({size - 2})"
+    oldLen = deque.len()
+    deque.insert(size - 2, 0x42362)
+    echo "Checking length"
+    doAssert oldLen + 1 == deque.len()
+    echo "Checking inserted value"
+    doAssert deque.pop(size - 2) == 0x42362
+    echo "Checking length"
+    doAssert deque.len() == oldLen
+    echo &"Checking insert({size div 2})"
+    oldLen = deque.len()
+    deque.insert(size div 2, 0xf7102)
+    echo "Checking length"
+    doAssert oldLen + 1 == deque.len()
+    echo "Checking inserted value"
+    doAssert deque.pop(size div 2) == 0xf7102
+    echo "Checking length"
+    doAssert deque.len() == oldLen
     echo "All tests passed!"