4 files changed, 46 insertions, 34 deletions
diff --git a/lib/pure/collections/intsets.nim b/lib/pure/collections/intsets.nim
index 38bc9d462..603a4b595 100644
--- a/lib/pure/collections/intsets.nim
+++ b/lib/pure/collections/intsets.nim
@@ -138,6 +138,8 @@ proc initIntSet*: IntSet =
   result.counter = 0
   result.head = nil
 
+proc isNil*(x: IntSet): bool {.inline.} = x.head.isNil
+
 proc assign*(dest: var IntSet, src: IntSet) =
   ## copies `src` to `dest`. `dest` does not need to be initialized by
   ## `initIntSet`.
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index bb6440652..37d52b6de 100644
--- a/lib/pure/collections/tables.nim
+++ b/lib/pure/collections/tables.nim
@@ -96,18 +96,10 @@ proc len*[A, B](t: Table[A, B]): int =
   ## returns the number of keys in `t`.
   result = t.counter
 
-proc `[]`*[A, B](t: Table[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 hc: Hash
-  var index = rawGet(t, key, hc)
-  if index >= 0: result = t.data[index].val
-
-proc mget*[A, B](t: var Table[A, B], key: A): var B =
+template get(t, key): untyped {.immediate.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
   ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  mixin rawGet
   var hc: Hash
   var index = rawGet(t, key, hc)
   if index >= 0: result = t.data[index].val
@@ -117,6 +109,12 @@ proc mget*[A, B](t: var Table[A, B], key: A): var B =
     else:
       raise newException(KeyError, "key not found")
 
+template getOrDefaultImpl(t, key): untyped {.immediate.} =
+  mixin rawGet
+  var hc: Hash
+  var index = rawGet(t, key, hc)
+  if index >= 0: result = t.data[index].val
+
 proc `[]`*[A, B](t: Table[A, B], key: A): B =
   ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
   ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
@@ -134,6 +132,8 @@ proc mget*[A, B](t: var Table[A, B], key: A): var B {.deprecated.} =
   ## instead.
   get(t, key)
 
+proc getOrDefault*[A, B](t: Table[A, B], key: A): B = getOrDefaultImpl(t, key)
+
 iterator allValues*[A, B](t: Table[A, B]; key: A): B =
   ## iterates over any value in the table `t` that belongs to the given `key`.
   var h: Hash = hash(key) and high(t.data)
@@ -305,6 +305,8 @@ proc mget*[A, B](t: TableRef[A, B], key: A): var B {.deprecated.} =
   ## Use ```[]``` instead.
   t[][key]
 
+proc getOrDefault*[A, B](t: TableRef[A, B], key: A): B = getOrDefault(t[], key)
+
 proc mgetOrPut*[A, B](t: TableRef[A, B], key: A, val: B): var B =
   ## retrieves value at ``t[key]`` or puts ``val`` if not present, either way
   ## returning a value which can be modified.
@@ -417,20 +419,6 @@ proc rawGet[A, B](t: OrderedTable[A, B], key: A, hc: var Hash): int =
   rawGetImpl()
 
 proc `[]`*[A, B](t: OrderedTable[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 hc: Hash
-  var index = rawGet(t, key, hc)
-  if index >= 0: result = t.data[index].val
-  else:
-    when compiles($key):
-      raise newException(KeyError, "key not found: " & $key)
-    else:
-      raise newException(KeyError, "key not found")
-
-proc `[]`*[A, B](t: OrderedTable[A, B], key: A): B =
   ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
   ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
   ## the key exists.
@@ -438,11 +426,18 @@ proc `[]`*[A, B](t: OrderedTable[A, B], key: A): B =
 
 proc `[]`*[A, B](t: var OrderedTable[A, B], key: A): var B =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  var hc: Hash
-  var index = rawGet(t, key, hc)
-  if index >= 0: result = t.data[index].val
-  else: raise newException(KeyError, "key not found: " & $key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  get(t, key)
+
+proc mget*[A, B](t: var OrderedTable[A, B], key: A): var B {.deprecated.} =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  get(t, key)
+
+proc getOrDefault*[A, B](t: OrderedTable[A, B], key: A): B =
+  getOrDefaultImpl(t, key)
+
 
 proc hasKey*[A, B](t: OrderedTable[A, B], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -612,6 +607,9 @@ proc mget*[A, B](t: OrderedTableRef[A, B], key: A): var B {.deprecated.} =
   ## Use ```[]``` instead.
   result = t[][key]
 
+proc getOrDefault*[A, B](t: OrderedTableRef[A, B], key: A): B =
+  getOrDefault(t[], key)
+
 proc mgetOrPut*[A, B](t: OrderedTableRef[A, B], key: A, val: B): var B =
   ## retrieves value at ``t[key]`` or puts ``val`` if not present, either way
   ## returning a value which can be modified.
@@ -711,7 +709,7 @@ proc rawGet[A](t: CountTable[A], key: A): int =
     h = nextTry(h, high(t.data))
   result = -1 - h                   # < 0 => MISSING; insert idx = -1 - result
 
-template get[A](t: CountTable[A], key: A): int {.immediate.} =
+template ctget(t, key: untyped): untyped {.immediate.} =
   var index = rawGet(t, key)
   if index >= 0: result = t.data[index].val
   else:
@@ -724,18 +722,22 @@ proc `[]`*[A](t: CountTable[A], key: A): int =
   ## retrieves the value at ``t[key]``. If `key` is not in `t`,
   ## the ``KeyError`` exception is raised. One can check with ``hasKey``
   ## whether the key exists.
-  get(t, key)
+  ctget(t, key)
 
 proc `[]`*[A](t: var CountTable[A], key: A): var int =
   ## retrieves the value at ``t[key]``. The value can be modified.
   ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  get(t, key)
+  ctget(t, key)
 
 proc mget*[A](t: var CountTable[A], key: A): var int {.deprecated.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
   ## If `key` is not in `t`, the ``KeyError`` exception is raised.
   ## Use ```[]``` instead.
-  get(t, key)
+  ctget(t, key)
+
+proc getOrDefault*[A](t: CountTable[A], key: A): int =
+  var index = rawGet(t, key)
+  if index >= 0: result = t.data[index].val
 
 proc hasKey*[A](t: CountTable[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -882,6 +884,9 @@ proc mget*[A](t: CountTableRef[A], key: A): var int {.deprecated.} =
   ## Use ```[]``` instead.
   result = t[][key]
 
+proc getOrDefault*[A](t: CountTableRef[A], key: A): int =
+  getOrDefaultImpl(t, key)
+
 proc hasKey*[A](t: CountTableRef[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
   result = t[].hasKey(key)
diff --git a/lib/pure/strtabs.nim b/lib/pure/strtabs.nim
index 2127c7f10..e477c6f07 100644
--- a/lib/pure/strtabs.nim
+++ b/lib/pure/strtabs.nim
@@ -122,6 +122,11 @@ proc mget*(t: StringTableRef, key: string): var string {.deprecated.} =
   ## ``KeyError`` exception is raised. Use ```[]``` instead.
   get(t, key)
 
+proc getOrDefault*(t: StringTableRef; key: string): string =
+  var index = rawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: result = ""
+
 proc hasKey*(t: StringTableRef, key: string): bool {.rtl, extern: "nst$1".} =
   ## returns true iff `key` is in the table `t`.
   result = rawGet(t, key) >= 0
diff --git a/lib/pure/xmltree.nim b/lib/pure/xmltree.nim
index c60da0239..4a506546b 100644
--- a/lib/pure/xmltree.nim
+++ b/lib/pure/xmltree.nim
@@ -144,7 +144,7 @@ proc `[]`* (n: var XmlNode, i: int): var XmlNode {.inline.} =
   assert n.k == xnElement
   result = n.s[i]
 
-proc mget* (n: var XmlNode, i: int): var XmlNode {.inline, deprecated.} =
+proc mget*(n: var XmlNode, i: int): var XmlNode {.inline, deprecated.} =
   ## returns the `i`'th child of `n` so that it can be modified. Use ```[]```
   ## instead.
   n[i]