Added support for ref type hash tables.

This reuses the hash table implementation for objects (and the
associated tests). For efficiency reasons, iterator implementations
are currently adapted rather than calling the TTable code.

tests/table/ptables.nim

@@ -0,0 +1,128 @@
+discard """
+  output: '''true'''
+"""
+
+import hashes, tables
+
+const
+  data = {
+    "34": 123456, "12": 789,
+    "90": 343, "0": 34404,
+    "1": 344004, "2": 344774,
+    "3": 342244, "4": 3412344,
+    "5": 341232144, "6": 34214544,
+    "7": 3434544, "8": 344544,
+    "9": 34435644, "---00": 346677844,
+    "10": 34484, "11": 34474, "19": 34464,
+    "20": 34454, "30": 34141244, "40": 344114,
+    "50": 344490, "60": 344491, "70": 344492,
+    "80": 344497}
+
+  sorteddata = {
+    "---00": 346677844,
+    "0": 34404,
+    "1": 344004,
+    "10": 34484, 
+    "11": 34474,
+    "12": 789,
+    "19": 34464,
+    "2": 344774, "20": 34454, 
+    "3": 342244, "30": 34141244,
+    "34": 123456,
+    "4": 3412344, "40": 344114,
+    "5": 341232144, "50": 344490, 
+    "6": 34214544, "60": 344491,
+    "7": 3434544, "70": 344492,
+    "8": 344544, "80": 344497,
+    "9": 34435644,
+    "90": 343}
+
+block tableTest1:
+  var t = newTable[tuple[x, y: int], string]()
+  t[(0,0)] = "00"
+  t[(1,0)] = "10"
+  t[(0,1)] = "01"
+  t[(1,1)] = "11"
+  for x in 0..1:
+    for y in 0..1:
+      assert t[(x,y)] == $x & $y
+  assert($t == 
+    "{(x: 0, y: 0): 00, (x: 0, y: 1): 01, (x: 1, y: 0): 10, (x: 1, y: 1): 11}")
+
+block tableTest2:
+  var t = newTable[string, float]()
+  t["test"] = 1.2345
+  t["111"] = 1.000043
+  t["123"] = 1.23
+  t.del("111")
+  
+  t["012"] = 67.9
+  t["123"] = 1.5 # test overwriting
+  
+  assert t["123"] == 1.5
+  assert t["111"] == 0.0 # deleted
+  assert(not hasKey(t, "111"))
+  
+  for key, val in items(data): t[key] = val.toFloat
+  for key, val in items(data): assert t[key] == val.toFloat
+  
+
+block orderedTableTest1:
+  var t = newOrderedTable[string, int](2)
+  for key, val in items(data): t[key] = val
+  for key, val in items(data): assert t[key] == val
+  var i = 0
+  # `pairs` needs to yield in insertion order:
+  for key, val in pairs(t):
+    assert key == data[i][0]
+    assert val == data[i][1]
+    inc(i)
+
+  for key, val in mpairs(t): val = 99
+  for val in mvalues(t): assert val == 99
+
+block countTableTest1:
+  var s = data.toTable
+  var t = newCountTable[string]()
+  for k in s.Keys: t.inc(k)
+  for k in t.keys: assert t[k] == 1
+  t.inc("90", 3)
+  t.inc("12", 2)
+  t.inc("34", 1)
+  assert t.largest()[0] == "90"
+
+  t.sort()
+  var i = 0
+  for k, v in t.pairs:
+    case i
+    of 0: assert k == "90" and v == 4
+    of 1: assert k == "12" and v == 3
+    of 2: assert k == "34" and v == 2
+    else: break
+    inc i
+
+block SyntaxTest:
+  var x = newTable[int, string]({:})
+
+proc orderedTableSortTest() =
+  var t = newOrderedTable[string, int](2)
+  for key, val in items(data): t[key] = val
+  for key, val in items(data): assert t[key] == val
+  t.sort(proc (x, y: tuple[key: string, val: int]): int = cmp(x.key, y.key))
+  var i = 0
+  # `pairs` needs to yield in sorted order:
+  for key, val in pairs(t):
+    doAssert key == sorteddata[i][0]
+    doAssert val == sorteddata[i][1]
+    inc(i)
+
+  # check that lookup still works:
+  for key, val in pairs(t):
+    doAssert val == t[key]
+  # check that insert still works:
+  t["newKeyHere"] = 80
+
+
+orderedTableSortTest()
+echo "true"
+