Exported extendLeft and added test for it. Added performance metrics and TODOs to README

README.md

@@ -102,3 +102,122 @@ some benchmarks as well as the test suite used to validate the behavior of the q
 3. The deque in that module is a value type
 4. I was bored during my programming class
 
+
+## Performance metrics
+------------------------------------------
+
+To outline just how much faster a deque is than a regular dynamic array when doing insertion and popping
+near the ends, here are some performance metrics I took on my laptop with an 8-core Ryzen 7 4700U.
+
+Both collections have been filled with 500000 elements and the time taken for each operation has been
+recorded. The average, minimum and maximum time taken are shown here, as well as the standard deviation
+for each micro-benchmark.
+
+
+## Appending at the end
+
+### LinkedDeque
+
+Time taken: `0.325591755` seconds. Results:
+
+  - min:   `0.0`
+  - max:   `0.010444388`
+  - avg:   `3.415999800000153e-07`
+  - stdev: `1.643969031599315e-05`
+
+### seq
+
+Time taken: `0.283606824` seconds. Results:
+
+  - min:   `2.499999999239222e-07`
+  - max:   `0.001853333999999984`
+  - avg:   `2.750403260000028e-07`
+  - stdev: `3.929418946682074e-06`
+
+## Popping the head
+
+### LinkedDeque
+
+Time taken: `0.008184640000000076` seconds. Results:
+
+  - min:   `2.499999999239222e-07`
+  - max:   `1.186499999994428e-05`
+  - avg:   `2.64712133333553e-07`
+  - stdev: `9.675646231323721e-08`
+
+### seq
+
+Time taken: `2.3356288` seconds. Results:
+
+  - min:   `0.0001166700000001519`
+  - max:   `0.002396426000000229`
+  - avg:   `0.0001549421693333322`
+  - stdev: `8.55174518472766e-05`
+
+## Adding at the left side
+
+### LinkedDeque
+
+Time taken: `0.3028111230000001` seconds. Results:
+
+  - min:   `2.699999996913505e-07`
+  - max:   `0.01986077199999992`
+  - avg:   `3.19837340000251e-07`
+  - stdev: `2.808711098829249e-05`
+
+### seq
+
+Time taken: `23.515489255` seconds. Results:
+
+  - min:   `2.700000001354397e-07`
+  - max:   `0.002371210999999818`
+  - avg:   `4.657242209800181e-05`
+  - stdev: `3.14827288610087e-05`
+
+## Random access (10000 times)
+
+### LinkedDeque
+
+Time taken: `8.208724628999995` seconds. Results:
+
+  - min:   `9.920000003660334e-07`
+  - max:   `0.002548661999998814`
+  - avg:   `0.0008192961785821358`
+  - stdev: `0.0004795569727666707`
+
+### seq
+
+Time taken: `0.00333773400000581` seconds. Results:
+
+  - min:   `1.599999990276046e-07`
+  - max:   `9.759999997527302e-06`
+  - avg:   `1.632506749111258e-07`
+  - stdev: `9.612951140246536e-08`
+
+## Popping the tail
+
+### LinkedDeque
+
+Time taken: `0.004907793000000993` seconds. Results:
+  - min:   `1.499999982002009e-07`
+  - max:   '8.515999994074264e-06`
+  - avg:   `1.609196000041869e-07`
+  - stdev: `9.069790474947947e-08`
+
+### seq
+
+Time taken: `0.004914629999994702` seconds. Results:
+  - min:   `1.499999982002009e-07`
+  - max:   `6.697999999971671e-06`
+  - avg:   `1.62365333385613e-07`
+  - stdev: `5.410771724203826e-08`
+
+
+## TODOs
+
+There are many possible implementations for double-ended queues: the current one is based on the usual textbook implementation of
+a doubly linked list, but that isn't the best choice for cache locality and has significant memory overhead for each link in
+the chain; Other possibilities involve using a list of subarrays to alleviate both of these issues, while some other options 
+make use of ring buffers or specialized dynamic arrays growing from the center that can be used to allow even fast random accessing 
+and can be made really efficient using lazy evaluation. The goal of this module is to implement most (possibly all) of these approaches, 
+because I find them fascinating.

src/nimdeque.nim

@@ -34,4 +34,5 @@ export insert
 export extend
 export reversedPairs
 export clear
-export clearPop
+export clearPop
+export extendLeft

tests/linked.nim

@@ -20,7 +20,7 @@ import ../src/nimdeque
 
 when isMainModule:
     const size = 1500
-    const benchSize = 1500000
+    const benchSize = 500000
 
     echo &"Running tests with queue of size {size}"
     var deque = newLinkedDeque[int]()
@@ -129,6 +129,12 @@ when isMainModule:
         doAssert deque[i] == s[i]
     doAssert old + len(s) == deque.len()
 
+    echo "\t- Testing extendLeft()"
+    old = deque.len()
+    deque.extendLeft(s)
+    for i in countup(0, 5):
+        doAssert deque[i] == s[5 - i]
+
     echo "\t- Testing clear()"
     deque.clear()
     doAssert deque.len() == 0