Merge pull request #1075 from flaviut/inlinedocs

Add some documentations and code examples in system

tests/misc/tsimplesort.nim

@@ -0,0 +1,313 @@
+discard """
+  output: '''true'''
+"""
+  
+import hashes, math
+
+
+when defined(shallowADT):
+  {.pragma: myShallow, shallow.}
+else:
+  {.pragma: myShallow.}
+
+type
+  TSlotEnum = enum seEmpty, seFilled, seDeleted
+  TKeyValuePair[A, B] = tuple[slot: TSlotEnum, key: A, val: B]
+  TKeyValuePairSeq[A, B] = seq[TKeyValuePair[A, B]]
+  TTable* {.final, myShallow.}[A, B] = object
+    data: TKeyValuePairSeq[A, B]
+    counter: int
+
+proc len*[A, B](t: TTable[A, B]): int =
+  ## returns the number of keys in `t`.
+  result = t.counter
+
+iterator pairs*[A, B](t: TTable[A, B]): tuple[key: A, val: B] =
+  ## iterates over any (key, value) pair in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield (t.data[h].key, t.data[h].val)
+
+iterator keys*[A, B](t: TTable[A, B]): A =
+  ## iterates over any key in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].key
+
+iterator values*[A, B](t: TTable[A, B]): B =
+  ## iterates over any value in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].val
+
+const
+  growthFactor = 2
+
+proc mustRehash(length, counter: int): bool {.inline.} =
+  assert(length > counter)
+  result = (length * 2 < counter * 3) or (length - counter < 4)
+
+proc nextTry(h, maxHash: THash): THash {.inline.} =
+  result = ((5 * h) + 1) and maxHash
+
+template rawGetImpl() =
+  var h: THash = hash(key) and high(t.data) # start with real hash value
+  while t.data[h].slot != seEmpty:
+    if t.data[h].key == key and t.data[h].slot == seFilled:
+      return h
+    h = nextTry(h, high(t.data))
+  result = -1
+
+template rawInsertImpl() =
+  var h: THash = hash(key) and high(data)
+  while data[h].slot == seFilled:
+    h = nextTry(h, high(data))
+  data[h].key = key
+  data[h].val = val
+  data[h].slot = seFilled
+
+proc RawGet[A, B](t: TTable[A, B], key: A): int =
+  rawGetImpl()
+
+proc `[]`*[A, B](t: TTable[A, B], key: A): B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## default empty value for the type `B` is returned
+  ## and no exception is raised. One can check with ``hasKey`` whether the key
+  ## exists.
+  var index = RawGet(t, key)
+  if index >= 0: result = t.data[index].val
+
+proc hasKey*[A, B](t: TTable[A, B], key: A): bool =
+  ## returns true iff `key` is in the table `t`.
+  result = rawGet(t, key) >= 0
+
+proc RawInsert[A, B](t: var TTable[A, B], data: var TKeyValuePairSeq[A, B],
+                     key: A, val: B) =
+  rawInsertImpl()
+
+proc Enlarge[A, B](t: var TTable[A, B]) =
+  var n: TKeyValuePairSeq[A, B]
+  newSeq(n, len(t.data) * growthFactor)
+  for i in countup(0, high(t.data)):
+    if t.data[i].slot == seFilled: RawInsert(t, n, t.data[i].key, t.data[i].val)
+  swap(t.data, n)
+
+template PutImpl() =
+  var index = RawGet(t, key)
+  if index >= 0:
+    t.data[index].val = val
+  else:
+    if mustRehash(len(t.data), t.counter): Enlarge(t)
+    RawInsert(t, t.data, key, val)
+    inc(t.counter)
+
+proc `[]=`*[A, B](t: var TTable[A, B], key: A, val: B) =
+  ## puts a (key, value)-pair into `t`.
+  putImpl()
+
+proc del*[A, B](t: var TTable[A, B], key: A) =
+  ## deletes `key` from hash table `t`.
+  var index = RawGet(t, key)
+  if index >= 0:
+    t.data[index].slot = seDeleted
+    dec(t.counter)
+
+proc initTable*[A, B](initialSize=64): TTable[A, B] =
+  ## creates a new hash table that is empty. `initialSize` needs to be
+  ## a power of two.
+  assert isPowerOfTwo(initialSize)
+  result.counter = 0
+  newSeq(result.data, initialSize)
+
+proc toTable*[A, B](pairs: openarray[tuple[key: A, 
+                    val: B]]): TTable[A, B] =
+  ## creates a new hash table that contains the given `pairs`.
+  result = initTable[A, B](nextPowerOfTwo(pairs.len+10))
+  for key, val in items(pairs): result[key] = val
+
+template dollarImpl(): stmt =
+  if t.len == 0:
+    result = "{:}"
+  else:
+    result = "{"
+    for key, val in pairs(t):
+      if result.len > 1: result.add(", ")
+      result.add($key)
+      result.add(": ")
+      result.add($val)
+    result.add("}")
+
+proc `$`*[A, B](t: TTable[A, B]): string =
+  ## The `$` operator for hash tables.
+  dollarImpl()
+
+# ------------------------------ count tables -------------------------------
+
+type
+  TCountTable* {.final, myShallow.}[
+      A] = object ## table that counts the number of each key
+    data: seq[tuple[key: A, val: int]]
+    counter: int
+
+proc len*[A](t: TCountTable[A]): int =
+  ## returns the number of keys in `t`.
+  result = t.counter
+
+iterator pairs*[A](t: TCountTable[A]): tuple[key: A, val: int] =
+  ## iterates over any (key, value) pair in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield (t.data[h].key, t.data[h].val)
+
+iterator keys*[A](t: TCountTable[A]): A =
+  ## iterates over any key in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield t.data[h].key
+
+iterator values*[A](t: TCountTable[A]): int =
+  ## iterates over any value in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield t.data[h].val
+
+proc RawGet[A](t: TCountTable[A], key: A): int =
+  var h: THash = hash(key) and high(t.data) # start with real hash value
+  while t.data[h].val != 0:
+    if t.data[h].key == key: return h
+    h = nextTry(h, high(t.data))
+  result = -1
+
+proc `[]`*[A](t: TCountTable[A], key: A): int =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## 0 is returned. One can check with ``hasKey`` whether the key
+  ## exists.
+  var index = RawGet(t, key)
+  if index >= 0: result = t.data[index].val
+
+proc hasKey*[A](t: TCountTable[A], key: A): bool =
+  ## returns true iff `key` is in the table `t`.
+  result = rawGet(t, key) >= 0
+
+proc RawInsert[A](t: TCountTable[A], data: var seq[tuple[key: A, val: int]],
+                  key: A, val: int) =
+  var h: THash = hash(key) and high(data)
+  while data[h].val != 0: h = nextTry(h, high(data))
+  data[h].key = key
+  data[h].val = val
+
+proc Enlarge[A](t: var TCountTable[A]) =
+  var n: seq[tuple[key: A, val: int]]
+  newSeq(n, len(t.data) * growthFactor)
+  for i in countup(0, high(t.data)):
+    if t.data[i].val != 0: RawInsert(t, n, t.data[i].key, t.data[i].val)
+  swap(t.data, n)
+
+proc `[]=`*[A](t: var TCountTable[A], key: A, val: int) =
+  ## puts a (key, value)-pair into `t`. `val` has to be positive.
+  assert val > 0
+  PutImpl()
+
+proc initCountTable*[A](initialSize=64): TCountTable[A] =
+  ## creates a new count table that is empty. `initialSize` needs to be
+  ## a power of two.
+  assert isPowerOfTwo(initialSize)
+  result.counter = 0
+  newSeq(result.data, initialSize)
+
+proc toCountTable*[A](keys: openArray[A]): TCountTable[A] =
+  ## creates a new count table with every key in `keys` having a count of 1.
+  result = initCountTable[A](nextPowerOfTwo(keys.len+10))
+  for key in items(keys): result[key] = 1
+
+proc `$`*[A](t: TCountTable[A]): string =
+  ## The `$` operator for count tables.
+  dollarImpl()
+
+proc inc*[A](t: var TCountTable[A], key: A, val = 1) = 
+  ## increments `t[key]` by `val`.
+  var index = RawGet(t, key)
+  if index >= 0:
+    inc(t.data[index].val, val)
+  else:
+    if mustRehash(len(t.data), t.counter): Enlarge(t)
+    RawInsert(t, t.data, key, val)
+    inc(t.counter)
+
+proc Smallest*[A](t: TCountTable[A]): tuple[key: A, val: int] =
+  ## returns the largest (key,val)-pair. Efficiency: O(n)
+  assert t.len > 0
+  var minIdx = 0
+  for h in 1..high(t.data):
+    if t.data[h].val > 0 and t.data[minIdx].val > t.data[h].val: minIdx = h
+  result.key = t.data[minIdx].key
+  result.val = t.data[minIdx].val
+
+proc Largest*[A](t: TCountTable[A]): tuple[key: A, val: int] =
+  ## returns the (key,val)-pair with the largest `val`. Efficiency: O(n)
+  assert t.len > 0
+  var maxIdx = 0
+  for h in 1..high(t.data):
+    if t.data[maxIdx].val < t.data[h].val: maxIdx = h
+  result.key = t.data[maxIdx].key
+  result.val = t.data[maxIdx].val
+
+proc sort*[A](t: var TCountTable[A]) =
+  ## sorts the count table so that the entry with the highest counter comes
+  ## first. This is destructive! You must not modify `t` afterwards!
+  ## You can use the iterators `pairs`,  `keys`, and `values` to iterate over
+  ## `t` in the sorted order.
+
+  # we use shellsort here; fast enough and simple
+  var h = 1
+  while true:
+    h = 3 * h + 1
+    if h >= high(t.data): break
+  while true:
+    h = h div 3
+    for i in countup(h, high(t.data)):
+      var j = i
+      while t.data[j-h].val <= t.data[j].val:
+        var xyz = t.data[j]
+        t.data[j] = t.data[j-h]
+        t.data[j-h] = xyz
+        j = j-h
+        if j < h: break
+    if h == 1: break
+
+
+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}
+
+proc countTableTest1 =
+  var s = initTable[string, int](64)
+  for key, val in items(data): s[key] = val
+  var w: tuple[key: string, val: int] #type(otherCountTable.data[0])
+
+  var t = initCountTable[string]()
+  for k, v in items(data): 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
+
+countTableTest1()
+echo true
+
+