Rename mget to []

- In sets, tables, strtabs, critbits, xmltree
- This uses the new var parameter overloading
- mget variants still exist, but are deprecated in favor of `[]`
- Includes tests and fixed tests and usages of mget
- The non-var `[]` now throws an exception instead of returning binary 0
  or an empty string

lib/pure/collections/critbits.nim

@@ -132,20 +132,31 @@ proc `[]=`*[T](c: var CritBitTree[T], key: string, val: T) =
   var n = rawInsert(c, key)
   n.val = val
 
-proc `[]`*[T](c: CritBitTree[T], key: string): T {.inline.} =
+template get[T](c: CritBitTree[T], key: string): T {.immediate.} =
-  ## retrieves the value at ``c[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.
   let n = rawGet(c, key)
   if n != nil: result = n.val
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
 
-proc mget*[T](c: var CritBitTree[T], key: string): var T {.inline.} =
+proc `[]`*[T](c: CritBitTree[T], key: string): T {.inline.} =
+  ## retrieves the value at ``c[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
+  get(c, key)
+
+proc `[]`*[T](c: var CritBitTree[T], key: string): var T {.inline.} =
   ## retrieves the value at ``c[key]``. The value can be modified.
   ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  let n = rawGet(c, key)
+  get(c, key)
-  if n != nil: result = n.val
+
-  else: raise newException(KeyError, "key not found: " & $key)
+proc mget*[T](c: var CritBitTree[T], key: string): var T {.inline, deprecated.} =
+  ## retrieves the value at ``c[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  get(c, key)
 
 proc excl*[T](c: var CritBitTree[T], key: string) =
   ## removes `key` (and its associated value) from the set `c`.
@@ -300,4 +311,3 @@ when isMainModule:
 
   for w in r.itemsWithPrefix("de"):
     echo w
-

lib/pure/collections/sets.nim

@@ -154,7 +154,7 @@ proc rawGetKnownHC[A](s: HashSet[A], key: A, hc: THash): int {.inline.} =
 proc rawGet[A](s: HashSet[A], key: A, hc: var THash): int {.inline.} =
   rawGetImpl()
 
-proc mget*[A](s: var HashSet[A], key: A): var A =
+proc `[]`*[A](s: var HashSet[A], key: A): var A =
   ## returns the element that is actually stored in 's' which has the same
   ## value as 'key' or raises the ``EInvalidKey`` exception. This is useful
   ## when one overloaded 'hash' and '==' but still needs reference semantics
@@ -165,6 +165,13 @@ proc mget*[A](s: var HashSet[A], key: A): var A =
   if index >= 0: result = s.data[index].key
   else: raise newException(KeyError, "key not found: " & $key)
 
+proc mget*[A](s: var HashSet[A], key: A): var A {.deprecated.} =
+  ## returns the element that is actually stored in 's' which has the same
+  ## value as 'key' or raises the ``EInvalidKey`` exception. This is useful
+  ## when one overloaded 'hash' and '==' but still needs reference semantics
+  ## for sharing. Use ```[]``` instead.
+  s[key]
+
 proc contains*[A](s: HashSet[A], key: A): bool =
   ## Returns true iff `key` is in `s`.
   ##

lib/pure/collections/tables.nim

@@ -181,18 +181,7 @@ proc rawGetDeep[A, B](t: Table[A, B], key: A, hc: var THash): int {.inline.} =
 proc rawGet[A, B](t: Table[A, B], key: A, hc: var THash): int {.inline.} =
   rawGetImpl()
 
-proc `[]`*[A, B](t: Table[A, B], key: A): B =
+template get[A, B](t: Table[A, B], key: A): B {.immediate.} =
-  ## 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: THash
-  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 =
-  ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
   var hc: THash
   var index = rawGet(t, key, hc)
   if index >= 0: result = t.data[index].val
@@ -202,6 +191,23 @@ proc mget*[A, B](t: var Table[A, B], key: A): var B =
     else:
       raise newException(KeyError, "key not found")
 
+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
+  ## the key exists.
+  get(t, key)
+
+proc `[]`*[A, B](t: var Table[A, B], key: A): var B =
+  ## 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)
+
+proc mget*[A, B](t: var Table[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)
+
 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: THash = hash(key) and high(t.data)
@@ -386,17 +392,17 @@ iterator mvalues*[A, B](t: TableRef[A, B]): var B =
   for h in 0..high(t.data):
     if isFilled(t.data[h].hcode): yield t.data[h].val
 
-proc `[]`*[A, B](t: TableRef[A, B], key: A): B =
+proc `[]`*[A, B](t: TableRef[A, B], key: A): var B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## retrieves the value at ``t[key]``.  If `key` is not in `t`, the
-  ## default empty value for the type `B` is returned
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
+  ## the key exists.
-  ## exists.
   result = t[][key]
 
-proc mget*[A, B](t: TableRef[A, B], key: A): var B =
+proc mget*[A, B](t: TableRef[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 ``EInvalidKey`` exception is raised.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  t[].mget(key)
+  ## Use ```[]``` instead.
+  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
@@ -510,22 +516,32 @@ proc rawGetDeep[A, B](t: OrderedTable[A, B], key: A, hc: var THash): int {.inlin
 proc rawGet[A, B](t: OrderedTable[A, B], key: A, hc: var THash): int =
   rawGetImpl()
 
-proc `[]`*[A, B](t: OrderedTable[A, B], key: A): B =
+template get[A, B](t: OrderedTable[A, B], key: A): B {.immediate.} =
-  ## 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: THash
   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 mget*[A, B](t: var OrderedTable[A, B], key: A): var B =
+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.
+  get(t, key)
+
+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.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  var hc: THash
+  get(t, key)
-  var index = rawGet(t, key, hc)
+
-  if index >= 0: result = t.data[index].val
+proc mget*[A, B](t: var OrderedTable[A, B], key: A): var B {.deprecated.} =
-  else: raise newException(KeyError, "key not found: " & $key)
+  ## 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 hasKey*[A, B](t: OrderedTable[A, B], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -679,17 +695,17 @@ iterator mvalues*[A, B](t: OrderedTableRef[A, B]): var B =
   forAllOrderedPairs:
     yield t.data[h].val
 
-proc `[]`*[A, B](t: OrderedTableRef[A, B], key: A): B =
+proc `[]`*[A, B](t: OrderedTableRef[A, B], key: A): var B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
-  ## default empty value for the type `B` is returned
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
+  ## the key exists.
-  ## exists.
   result = t[][key]
 
-proc mget*[A, B](t: OrderedTableRef[A, B], key: A): var B =
+proc mget*[A, B](t: OrderedTableRef[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 ``EInvalidKey`` exception is raised.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  result = t[].mget(key)
+  ## Use ```[]``` instead.
+  result = 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
@@ -786,19 +802,31 @@ 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.} =
+  var index = rawGet(t, key)
+  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](t: CountTable[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
+  ## the ``KeyError`` exception is raised. One can check with ``hasKey``
-  ## exists.
+  ## whether the key exists.
-  var index = rawGet(t, key)
+  get(t, key)
-  if index >= 0: result = t.data[index].val
 
-proc mget*[A](t: var CountTable[A], key: A): var int =
+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 ``EInvalidKey`` exception is raised.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  var index = rawGet(t, key)
+  get(t, key)
-  if index >= 0: result = t.data[index].val
+
-  else: raise newException(KeyError, "key not found: " & $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)
 
 proc hasKey*[A](t: CountTable[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -927,16 +955,16 @@ iterator mvalues*[A](t: CountTableRef[A]): var int =
   for h in 0..high(t.data):
     if t.data[h].val != 0: yield t.data[h].val
 
-proc `[]`*[A](t: CountTableRef[A], key: A): int =
+proc `[]`*[A](t: CountTableRef[A], key: A): var int =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## retrieves the value at ``t[key]``. The value can be modified.
-  ## 0 is returned. One can check with ``hasKey`` whether the key
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  ## exists.
   result = t[][key]
 
-proc mget*[A](t: CountTableRef[A], key: A): var int =
+proc mget*[A](t: CountTableRef[A], key: A): var int {.deprecated.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  result = t[].mget(key)
+  ## Use ```[]``` instead.
+  result = t[][key]
 
 proc hasKey*[A](t: CountTableRef[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.

lib/pure/strtabs.nim

@@ -101,21 +101,26 @@ proc rawGet(t: StringTableRef, key: string): int =
     h = nextTry(h, high(t.data))
   result = - 1
 
-proc `[]`*(t: StringTableRef, key: string): string {.rtl, extern: "nstGet".} =
+template get(t: StringTableRef, key: string): stmt {.immediate.} =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`, "" 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
-  else: result = ""
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
 
-proc mget*(t: StringTableRef, key: string): var string {.
+proc `[]`*(t: StringTableRef, key: string): var string {.
-             rtl, extern: "nstTake".} =
+           rtl, extern: "nstTake".} =
   ## retrieves the location at ``t[key]``. If `key` is not in `t`, the
-  ## ``KeyError`` exception is raised.
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
-  var index = rawGet(t, key)
+  ## the key exists.
-  if index >= 0: result = t.data[index].val
+  get(t, key)
-  else: raise newException(KeyError, "key does not exist: " & key)
+
+proc mget*(t: StringTableRef, key: string): var string {.deprecated.} =
+  ## retrieves the location at ``t[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. Use ```[]``` instead.
+  get(t, key)
 
 proc hasKey*(t: StringTableRef, key: string): bool {.rtl, extern: "nst$1".} =
   ## returns true iff `key` is in the table `t`.
@@ -239,6 +244,6 @@ when isMainModule:
   assert x["k"] == "v"
   assert x["11"] == "22"
   assert x["565"] == "67"
-  x.mget("11") = "23"
+  x["11"] = "23"
   assert x["11"] == "23"
 

lib/pure/xmltree.nim

@@ -115,11 +115,16 @@ proc `[]`* (n: XmlNode, i: int): XmlNode {.inline.} =
   assert n.k == xnElement
   result = n.s[i]
 
-proc mget* (n: var XmlNode, i: int): var XmlNode {.inline.} =
+proc `[]`* (n: var XmlNode, i: int): var XmlNode {.inline.} =
   ## returns the `i`'th child of `n` so that it can be modified
   assert n.k == xnElement
   result = n.s[i]
 
+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]
+
 iterator items*(n: XmlNode): XmlNode {.inline.} =
   ## iterates over any child of `n`.
   assert n.k == xnElement
@@ -128,7 +133,7 @@ iterator items*(n: XmlNode): XmlNode {.inline.} =
 iterator mitems*(n: var XmlNode): var XmlNode {.inline.} =
   ## iterates over any child of `n`.
   assert n.k == xnElement
-  for i in 0 .. n.len-1: yield mget(n, i)
+  for i in 0 .. n.len-1: yield n[i]
 
 proc attrs*(n: XmlNode): XmlAttributes {.inline.} =
   ## gets the attributes belonging to `n`.

tests/actiontable/tactiontable.nim

@@ -24,4 +24,3 @@ var
     "D": action4}.toTable
 
 actionTable["C"]("arg")
-

tests/collections/ttables.nim

@@ -60,7 +60,10 @@ block tableTest2:
   t["123"] = 1.5 # test overwriting
 
   assert t["123"] == 1.5
-  assert t["111"] == 0.0 # deleted
+  try:
+    echo t["111"] # deleted
+  except KeyError:
+    discard
   assert(not hasKey(t, "111"))
 
   for key, val in items(data): t[key] = val.toFloat

tests/collections/ttablesref.nim

@@ -60,7 +60,10 @@ block tableTest2:
   t["123"] = 1.5 # test overwriting
 
   assert t["123"] == 1.5
-  assert t["111"] == 0.0 # deleted
+  try:
+    echo t["111"] # deleted
+  except KeyError:
+    discard
   assert(not hasKey(t, "111"))
 
   for key, val in items(data): t[key] = val.toFloat

tests/misc/teventemitter.nim

@@ -18,7 +18,7 @@ proc on*(emitter: var EventEmitter, event: string,
   if not hasKey(emitter.events, event):
     var list: DoublyLinkedList[proc(e: EventArgs) {.nimcall.}]
     add(emitter.events, event, list) #if not, add it.
-  append(emitter.events.mget(event), fn)
+  append(emitter.events[event], fn)
 
 proc initEmitter(emitter: var EventEmitter) =
   emitter.events = initTable[string,
@@ -30,4 +30,3 @@ var
 initEmitter(ee)
 ee.on("print", proc(e: EventArgs) = echo("pie"))
 ee.emit("print", args)
-

tests/stdlib/tmget.nim

@@ -0,0 +1,141 @@
+discard """
+  output: '''Can't access 6
+10
+11
+Can't access 6
+10
+11
+Can't access 6
+10
+11
+Can't access 6
+10
+11
+Can't access 6
+10
+11
+Can't access 6
+10
+11
+Can't access 6
+5
+Can't access 6
+10
+11
+Can't access 6
+10
+11'''
+"""
+
+import tables
+
+block:
+  var x = initTable[int, int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+block:
+  var x = newTable[int, int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+block:
+  var x = initOrderedTable[int, int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+block:
+  var x = newOrderedTable[int, int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+block:
+  var x = initCountTable[int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+block:
+  var x = newCountTable[int]()
+  x[5] = 10
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+  x[5] += 1
+  var c = x[5]
+  echo c
+
+import sets
+
+block:
+  var x = initSet[int]()
+  x.incl 5
+  try:
+    echo x[6]
+  except KeyError:
+    echo "Can't access 6"
+  echo x[5]
+
+import critbits
+
+block:
+  var x: CritBitTree[int]
+  x["5"] = 10
+  try:
+    echo x["6"]
+  except KeyError:
+    echo "Can't access 6"
+  echo x["5"]
+  x["5"] += 1
+  var c = x["5"]
+  echo c
+
+import strtabs
+
+block:
+  var x = newStringTable()
+  x["5"] = "10"
+  try:
+    echo x["6"]
+  except KeyError:
+    echo "Can't access 6"
+  echo x["5"]
+  x["5"][1] = '1'
+  var c = x["5"]
+  echo c

tests/stdlib/tmitems.nim

@@ -132,5 +132,5 @@ block:
   </Students>""")
   for x in d.mitems:
     x = <>Student(Name=x.attrs["Name"] & "foo")
-  d.mget(1).attrs["Name"] = "bar"
+  d[1].attrs["Name"] = "bar"
   echo d