3 files changed, 63 insertions, 18 deletions
diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 00056ff14..5f4b5a530 100755
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -10,17 +10,12 @@
 ## The ``sets`` module implements an efficient hash set and ordered hash set.
 ##
 ## **Note**: The data types declared here have *value semantics*: This means
-## that ``=`` performs a copy of the hash table. If you are overly concerned
-## with efficiency and know what you do (!), you can define the symbol
-## ``shallowADT`` to compile a version that uses shallow copies instead.
+## that ``=`` performs a copy of the set.
 
 import
   os, hashes, math
 
-when defined(shallowADT):
-  {.pragma: myShallow, shallow.}
-else:
-  {.pragma: myShallow.}
+{.pragma: myShallow.}
 
 type
   TSlotEnum = enum seEmpty, seFilled, seDeleted
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index 6fe77b26f..31b98a0cc 100755
--- a/lib/pure/collections/tables.nim
+++ b/lib/pure/collections/tables.nim
@@ -11,17 +11,12 @@
 ## a mapping from keys to values.
 ##
 ## **Note:** The data types declared here have *value semantics*: This means
-## that ``=`` performs a copy of the hash table. If you are overly concerned
-## with efficiency and know what you do (!), you can define the symbol
-## ``shallowADT`` to compile a version that uses shallow copies instead.
+## that ``=`` performs a copy of the hash table.
 
 import
   hashes, math
 
-when defined(shallowADT):
-  {.pragma: myShallow, shallow.}
-else:
-  {.pragma: myShallow.}
+{.pragma: myShallow.}
 
 type
   TSlotEnum = enum seEmpty, seFilled, seDeleted
@@ -40,6 +35,12 @@ iterator pairs*[A, B](t: TTable[A, B]): tuple[key: A, val: B] =
   for h in 0..high(t.data):
     if t.data[h].slot == seFilled: yield (t.data[h].key, t.data[h].val)
 
+iterator mpairs*[A, B](t: var TTable[A, B]): tuple[key: A, val: var B] =
+  ## iterates over any (key, value) pair in the table `t`. The values
+  ## can be modified.
+  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):
@@ -50,6 +51,11 @@ iterator values*[A, B](t: TTable[A, B]): B =
   for h in 0..high(t.data):
     if t.data[h].slot == seFilled: yield t.data[h].val
 
+iterator mvalues*[A, B](t: var TTable[A, B]): var B =
+  ## iterates over any value in the table `t`. The values can be modified.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].val
+
 const
   growthFactor = 2
 
@@ -87,6 +93,13 @@ proc `[]`*[A, B](t: TTable[A, B], key: A): B =
   var index = RawGet(t, key)
   if index >= 0: result = t.data[index].val
 
+proc mget*[A, B](t: var TTable[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 index = RawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: raise newException(EInvalidKey, "key not found: " & $key)
+
 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
@@ -197,6 +210,12 @@ iterator pairs*[A, B](t: TOrderedTable[A, B]): tuple[key: A, val: B] =
   forAllOrderedPairs:
     yield (t.data[h].key, t.data[h].val)
 
+iterator mpairs*[A, B](t: var TOrderedTable[A, B]): tuple[key: A, val: var B] =
+  ## iterates over any (key, value) pair in the table `t` in insertion
+  ## order. The values can be modified.
+  forAllOrderedPairs:
+    yield (t.data[h].key, t.data[h].val)
+
 iterator keys*[A, B](t: TOrderedTable[A, B]): A =
   ## iterates over any key in the table `t` in insertion order.
   forAllOrderedPairs:
@@ -207,6 +226,12 @@ iterator values*[A, B](t: TOrderedTable[A, B]): B =
   forAllOrderedPairs:
     yield t.data[h].val
 
+iterator mvalues*[A, B](t: var TOrderedTable[A, B]): var B =
+  ## iterates over any value in the table `t` in insertion order. The values
+  ## can be modified.
+  forAllOrderedPairs:
+    yield t.data[h].val
+
 proc RawGet[A, B](t: TOrderedTable[A, B], key: A): int =
   rawGetImpl()
 
@@ -218,6 +243,13 @@ proc `[]`*[A, B](t: TOrderedTable[A, B], key: A): B =
   var index = RawGet(t, key)
   if index >= 0: result = t.data[index].val
 
+proc mget*[A, B](t: var TOrderedTable[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 index = RawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: raise newException(EInvalidKey, "key not found: " & $key)
+
 proc hasKey*[A, B](t: TOrderedTable[A, B], key: A): bool =
   ## returns true iff `key` is in the table `t`.
   result = rawGet(t, key) >= 0
@@ -288,6 +320,12 @@ iterator pairs*[A](t: TCountTable[A]): tuple[key: A, val: int] =
   for h in 0..high(t.data):
     if t.data[h].val != 0: yield (t.data[h].key, t.data[h].val)
 
+iterator mpairs*[A](t: var TCountTable[A]): tuple[key: A, val: var int] =
+  ## iterates over any (key, value) pair in the table `t`. The values can
+  ## be modified.
+  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):
@@ -298,6 +336,11 @@ iterator values*[A](t: TCountTable[A]): int =
   for h in 0..high(t.data):
     if t.data[h].val != 0: yield t.data[h].val
 
+iterator mvalues*[A](t: TCountTable[A]): var int =
+  ## iterates over any value in the table `t`. The values can be modified.
+  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:
@@ -312,6 +355,13 @@ proc `[]`*[A](t: TCountTable[A], key: A): int =
   var index = RawGet(t, key)
   if index >= 0: result = t.data[index].val
 
+proc mget*[A](t: var TCountTable[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.
+  var index = RawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: raise newException(EInvalidKey, "key not found: " & $key)
+
 proc hasKey*[A](t: TCountTable[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
   result = rawGet(t, key) >= 0
diff --git a/lib/pure/strtabs.nim b/lib/pure/strtabs.nim
index 584282fbc..a9ce9016c 100755
--- a/lib/pure/strtabs.nim
+++ b/lib/pure/strtabs.nim
@@ -92,13 +92,13 @@ proc `[]`*(t: PStringTable, key: string): string {.rtl, extern: "nstGet".} =
   if index >= 0: result = t.data[index].val
   else: result = ""
 
-proc modGet*(t: PStringTable, key: string): var string {.
+proc mget*(t: PStringTable, key: string): var string {.
              rtl, extern: "nstTake".} =
   ## retrieves the location at ``t[key]``. If `key` is not in `t`, the
-  ## ``EInvalidValue`` exception is raised.
+  ## ``EInvalidKey`` exception is raised.
   var index = RawGet(t, key)
   if index >= 0: result = t.data[index].val
-  else: raise newException(EInvalidValue, "key does not exist: " & key)
+  else: raise newException(EInvalidKey, "key does not exist: " & key)
 
 proc hasKey*(t: PStringTable, key: string): bool {.rtl, extern: "nst$1".} =
   ## returns true iff `key` is in the table `t`.
@@ -221,6 +221,6 @@ when isMainModule:
   assert x["k"] == "v"
   assert x["11"] == "22"
   assert x["565"] == "67"
-  x.modGet("11") = "23"
+  x.mget("11") = "23"
   assert x["11"] == "23"