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The tables module implements variants of an efficient hash table (also often named dictionary in other programming languages) that is a mapping from keys to values.

There are several different types of hash tables available:

  • Table is the usual hash table,
  • OrderedTable is like Table but remembers insertion order,
  • CountTable is a mapping from a key to its number of occurrences

For consistency with every other data type in Nim these have value semantics, this means that = performs a copy of the hash table.

For ref semantics use their Ref variants: TableRef, OrderedTableRef, and CountTableRef.

To give an example, when a is a Table, then var b = a gives b as a new independent table. b is initialised with the contents of a. Changing b does not affect a and vice versa:

import tables

var
  a = {1: "one", 2: "two"}.toTable  # creates a Table
  b = a

echo a, b  # output: {1: one, 2: two}{1: one, 2: two}

b[3] = "three"
echo a, b  # output: {1: one, 2: two}{1: one, 2: two, 3: three}
echo a == b  # output: false

On the other hand, when a is a TableRef instead, then changes to b also affect a. Both a and b ref the same data structure:

import tables

var
  a = {1: "one", 2: "two"}.newTable  # creates a TableRef
  b = a

echo a, b  # output: {1: one, 2: two}{1: one, 2: two}

b[3] = "three"
echo a, b  # output: {1: one, 2: two, 3: three}{1: one, 2: two, 3: three}
echo a == b  # output: true

Basic usage

Table

import tables
from sequtils import zip

let
  names = ["John", "Paul", "George", "Ringo"]
  years = [1940, 1942, 1943, 1940]

var beatles = initTable[string, int]()

for pairs in zip(names, years):
  let (name, birthYear) = pairs
  beatles[name] = birthYear

echo beatles
# {"George": 1943, "Ringo": 1940, "Paul": 1942, "John": 1940}


var beatlesByYear = initTable[int, seq[string]]()

for pairs in zip(years, names):
  let (birthYear, name) = pairs
  if not beatlesByYear.hasKey(birthYear):
    # if a key doesn't exist, we create one with an empty sequence
    # before we can add elements to it
    beatlesByYear[birthYear] = @[]
  beatlesByYear[birthYear].add(name)

echo beatlesByYear
# {1940: @["John", "Ringo"], 1942: @["Paul"], 1943: @["George"]}

OrderedTable

OrderedTable is used when it is important to preserve the insertion order of keys.

import tables

let
  a = [('z', 1), ('y', 2), ('x', 3)]
  t = a.toTable          # regular table
  ot = a.toOrderedTable  # ordered tables

echo t   # {'x': 3, 'y': 2, 'z': 1}
echo ot  # {'z': 1, 'y': 2, 'x': 3}

CountTable

CountTable is useful for counting number of items of some container (e.g. string, sequence or array), as it is a mapping where the items are the keys, and their number of occurrences are the values. For that purpose toCountTable proc comes handy:

import tables

let myString = "abracadabra"
let letterFrequencies = toCountTable(myString)
echo letterFrequencies
# 'a': 5, 'b': 2, 'c': 1, 'd': 1, 'r': 2}

The same could have been achieved by manually iterating over a container and increasing each key's value with inc proc:

import tables

let myString = "abracadabra"
var letterFrequencies = initCountTable[char]()
for c in myString:
  letterFrequencies.inc(c)
echo letterFrequencies
# output: {'a': 5, 'b': 2, 'c': 1, 'd': 1, 'r': 2}

Hashing

If you are using simple standard types like int or string for the keys of the table you won't have any problems, but as soon as you try to use a more complex object as a key you will be greeted by a strange compiler error:

Error: type mismatch: got (Person) but expected one of: hashes.hash(x: openArray[A]): Hash hashes.hash(x: int): Hash hashes.hash(x: float): Hash …

What is happening here is that the types used for table keys require to have a hash() proc which will convert them to a Hash value, and the compiler is listing all the hash functions it knows. Additionally there has to be a == operator that provides the same semantics as its corresponding hash proc.

After you add hash and == for your custom type everything will work. Currently, however, hash for objects is not defined, whereas system.== for objects does exist and performs a "deep" comparison (every field is compared) which is usually what you want. So in the following example implementing only hash suffices:

import tables, hashes

type
  Person = object
    firstName, lastName: string

proc hash(x: Person): Hash =
  ## Piggyback on the already available string hash proc.
  ##
  ## Without this proc nothing works!
  result = x.firstName.hash !& x.lastName.hash
  result = !$result

var
  salaries = initTable[Person, int]()
  p1, p2: Person

p1.firstName = "Jon"
p1.lastName = "Ross"
salaries[p1] = 30_000

p2.firstName = "소진"
p2.lastName = "박"
salaries[p2] = 45_000

See also

Types

Table[A; B] = object
  data: KeyValuePairSeq[A, B]
  counter: int

Generic hash table, consisting of a key-value pair.

data and counter are internal implementation details which can't be accessed.

For creating an empty Table, use initTable proc.

  Source Edit
TableRef[A; B] = ref Table[A, B]

Ref version of Table.

For creating a new empty TableRef, use newTable proc.

  Source Edit
OrderedTable[A; B] = object
  data: OrderedKeyValuePairSeq[A, B]
  counter, first, last: int

Hash table that remembers insertion order.

For creating an empty OrderedTable, use initOrderedTable proc.

  Source Edit
OrderedTableRef[A; B] = ref OrderedTable[A, B]

Ref version of OrderedTable.

For creating a new empty OrderedTableRef, use newOrderedTable proc.

  Source Edit
CountTable[A] = object
  data: seq[tuple[key: A, val: int]]
  counter: int
  isSorted: bool

Hash table that counts the number of each key.

For creating an empty CountTable, use initCountTable proc.

  Source Edit
CountTableRef[A] = ref CountTable[A]

Ref version of CountTable.

For creating a new empty CountTableRef, use newCountTable proc.

  Source Edit

Procs

proc initTable[A, B](initialsize = defaultInitialSize): Table[A, B]

Creates a new hash table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

Starting from Nim v0.20, tables are initialized by default and it is not necessary to call this function explicitly.

See also:

Examples:

let
  a = initTable[int, string]()
  b = initTable[char, seq[int]]()
  Source Edit
proc toTable[A, B](pairs: openArray[(A, B)]): Table[A, B]

Creates a new hash table that contains the given pairs.

pairs is a container consisting of (key, value) tuples.

See also:

Examples:

let a = [('a', 5), ('b', 9)]
let b = toTable(a)
assert b == {'a': 5, 'b': 9}.toTable
  Source Edit
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 proc whether the key exists.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert a['a'] == 5
doAssertRaises(KeyError):
  echo a['z']
  Source Edit
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.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table
  Source Edit
proc `[]=`[A, B](t: var Table[A, B]; key: A; val: B)

Inserts a (key, value) pair into t.

See also:

Examples:

var a = initTable[char, int]()
a['x'] = 7
a['y'] = 33
doAssert a == {'x': 7, 'y': 33}.toTable
  Source Edit
proc hasKey[A, B](t: Table[A, B]; key: A): bool

Returns true if key is in the table t.

See also:

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert a.hasKey('a') == true
doAssert a.hasKey('z') == false
  Source Edit
proc contains[A, B](t: Table[A, B]; key: A): bool
Alias of hasKey proc for use with the in operator.

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert 'b' in a == true
doAssert a.contains('z') == false
  Source Edit
proc hasKeyOrPut[A, B](t: var Table[A, B]; key: A; val: B): bool

Returns true if key is in the table, otherwise inserts value.

See also:

Examples:

var a = {'a': 5, 'b': 9}.toTable
if a.hasKeyOrPut('a', 50):
  a['a'] = 99
if a.hasKeyOrPut('z', 50):
  a['z'] = 99
doAssert a == {'a': 99, 'b': 9, 'z': 50}.toTable
  Source Edit
proc getOrDefault[A, B](t: Table[A, B]; key: A): B

Retrieves the value at t[key] if key is in t. Otherwise, the default initialization value for type B is returned (e.g. 0 for any integer type).

See also:

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert a.getOrDefault('a') == 5
doAssert a.getOrDefault('z') == 0
  Source Edit
proc getOrDefault[A, B](t: Table[A, B]; key: A; default: B): B

Retrieves the value at t[key] if key is in t. Otherwise, default is returned.

See also:

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert a.getOrDefault('a', 99) == 5
doAssert a.getOrDefault('z', 99) == 99
  Source Edit
proc mgetOrPut[A, B](t: var Table[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.

See also:

Examples:

var a = {'a': 5, 'b': 9}.toTable
doAssert a.mgetOrPut('a', 99) == 5
doAssert a.mgetOrPut('z', 99) == 99
doAssert a == {'a': 5, 'b': 9, 'z': 99}.toTable
  Source Edit
proc len[A, B](t: Table[A, B]): int
Returns the number of keys in t.

Examples:

let a = {'a': 5, 'b': 9}.toTable
doAssert len(a) == 2
  Source Edit
proc add[A, B](t: var Table[A, B]; key: A; val: B)

Puts a new (key, value) pair into t even if t[key] already exists.

This can introduce duplicate keys into the table!

Use []= proc for inserting a new (key, value) pair in the table without introducing duplicates.

  Source Edit
proc del[A, B](t: var Table[A, B]; key: A)

Deletes key from hash table t. Does nothing if the key does not exist.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.toTable
a.del('a')
doAssert a == {'b': 9, 'c': 13}.toTable
a.del('z')
doAssert a == {'b': 9, 'c': 13}.toTable
  Source Edit
proc take[A, B](t: var Table[A, B]; key: A; val: var B): bool

Deletes the key from the table. Returns true, if the key existed, and sets val to the mapping of the key. Otherwise, returns false, and the val is unchanged.

See also:

Examples:

var
  a = {'a': 5, 'b': 9, 'c': 13}.toTable
  i: int
doAssert a.take('b', i) == true
doAssert a == {'a': 5, 'c': 13}.toTable
doAssert i == 9
i = 0
doAssert a.take('z', i) == false
doAssert a == {'a': 5, 'c': 13}.toTable
doAssert i == 0
  Source Edit
proc clear[A, B](t: var Table[A, B])

Resets the table so that it is empty.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.toTable
doAssert len(a) == 3
clear(a)
doAssert len(a) == 0
  Source Edit
proc `$`[A, B](t: Table[A, B]): string
The $ operator for hash tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A, B](s, t: Table[A, B]): bool
The == operator for hash tables. Returns true if the content of both tables contains the same key-value pairs. Insert order does not matter.

Examples:

let
  a = {'a': 5, 'b': 9, 'c': 13}.toTable
  b = {'b': 9, 'c': 13, 'a': 5}.toTable
doAssert a == b
  Source Edit
proc rightSize(count: Natural): int {...}{.inline, raises: [], tags: [].}

Return the value of initialSize to support count items.

If more items are expected to be added, simply add that expected extra amount to the parameter before calling this.

Internally, we want mustRehash(rightSize(x), x) == false.

  Source Edit
proc indexBy[A, B, C](collection: A; index: proc (x: B): C): Table[C, B]
Index the collection with the proc provided.   Source Edit
proc newTable[A, B](initialsize = defaultInitialSize): <//>TableRef[A, B]

Creates a new ref hash table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

See also:

Examples:

let
  a = newTable[int, string]()
  b = newTable[char, seq[int]]()
  Source Edit
proc newTable[A, B](pairs: openArray[(A, B)]): <//>TableRef[A, B]

Creates a new ref hash table that contains the given pairs.

pairs is a container consisting of (key, value) tuples.

See also:

Examples:

let a = [('a', 5), ('b', 9)]
let b = newTable(a)
assert b == {'a': 5, 'b': 9}.newTable
  Source Edit
proc newTableFrom[A, B, C](collection: A; index: proc (x: B): C): <//>TableRef[C, B]
Index the collection with the proc provided.   Source Edit
proc `[]`[A, B](t: TableRef[A, B]; key: A): var B

Retrieves the value at t[key].

If key is not in t, the KeyError exception is raised. One can check with hasKey proc whether the key exists.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert a['a'] == 5
doAssertRaises(KeyError):
  echo a['z']
  Source Edit
proc `[]=`[A, B](t: TableRef[A, B]; key: A; val: B)

Inserts a (key, value) pair into t.

See also:

Examples:

var a = newTable[char, int]()
a['x'] = 7
a['y'] = 33
doAssert a == {'x': 7, 'y': 33}.newTable
  Source Edit
proc hasKey[A, B](t: TableRef[A, B]; key: A): bool

Returns true if key is in the table t.

See also:

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert a.hasKey('a') == true
doAssert a.hasKey('z') == false
  Source Edit
proc contains[A, B](t: TableRef[A, B]; key: A): bool
Alias of hasKey proc for use with the in operator.

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert 'b' in a == true
doAssert a.contains('z') == false
  Source Edit
proc hasKeyOrPut[A, B](t: var TableRef[A, B]; key: A; val: B): bool

Returns true if key is in the table, otherwise inserts value.

See also:

Examples:

var a = {'a': 5, 'b': 9}.newTable
if a.hasKeyOrPut('a', 50):
  a['a'] = 99
if a.hasKeyOrPut('z', 50):
  a['z'] = 99
doAssert a == {'a': 99, 'b': 9, 'z': 50}.newTable
  Source Edit
proc getOrDefault[A, B](t: TableRef[A, B]; key: A): B

Retrieves the value at t[key] if key is in t. Otherwise, the default initialization value for type B is returned (e.g. 0 for any integer type).

See also:

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert a.getOrDefault('a') == 5
doAssert a.getOrDefault('z') == 0
  Source Edit
proc getOrDefault[A, B](t: TableRef[A, B]; key: A; default: B): B

Retrieves the value at t[key] if key is in t. Otherwise, default is returned.

See also:

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert a.getOrDefault('a', 99) == 5
doAssert a.getOrDefault('z', 99) == 99
  Source Edit
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.

See also:

Examples:

var a = {'a': 5, 'b': 9}.newTable
doAssert a.mgetOrPut('a', 99) == 5
doAssert a.mgetOrPut('z', 99) == 99
doAssert a == {'a': 5, 'b': 9, 'z': 99}.newTable
  Source Edit
proc len[A, B](t: TableRef[A, B]): int
Returns the number of keys in t.

Examples:

let a = {'a': 5, 'b': 9}.newTable
doAssert len(a) == 2
  Source Edit
proc add[A, B](t: TableRef[A, B]; key: A; val: B)

Puts a new (key, value) pair into t even if t[key] already exists.

This can introduce duplicate keys into the table!

Use []= proc for inserting a new (key, value) pair in the table without introducing duplicates.

  Source Edit
proc del[A, B](t: TableRef[A, B]; key: A)

Deletes key from hash table t. Does nothing if the key does not exist.

If duplicate keys were added, this may need to be called multiple times.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.newTable
a.del('a')
doAssert a == {'b': 9, 'c': 13}.newTable
a.del('z')
doAssert a == {'b': 9, 'c': 13}.newTable
  Source Edit
proc take[A, B](t: TableRef[A, B]; key: A; val: var B): bool

Deletes the key from the table. Returns true, if the key existed, and sets val to the mapping of the key. Otherwise, returns false, and the val is unchanged.

If duplicate keys were added, this may need to be called multiple times.

See also:

Examples:

var
  a = {'a': 5, 'b': 9, 'c': 13}.newTable
  i: int
doAssert a.take('b', i) == true
doAssert a == {'a': 5, 'c': 13}.newTable
doAssert i == 9
i = 0
doAssert a.take('z', i) == false
doAssert a == {'a': 5, 'c': 13}.newTable
doAssert i == 0
  Source Edit
proc clear[A, B](t: TableRef[A, B])

Resets the table so that it is empty.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.newTable
doAssert len(a) == 3
clear(a)
doAssert len(a) == 0
  Source Edit
proc `$`[A, B](t: TableRef[A, B]): string
The $ operator for hash tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A, B](s, t: TableRef[A, B]): bool
The == operator for hash tables. Returns true if either both tables are nil, or neither is nil and the content of both tables contains the same key-value pairs. Insert order does not matter.

Examples:

let
  a = {'a': 5, 'b': 9, 'c': 13}.newTable
  b = {'b': 9, 'c': 13, 'a': 5}.newTable
doAssert a == b
  Source Edit
proc initOrderedTable[A, B](initialsize = defaultInitialSize): OrderedTable[A, B]

Creates a new ordered hash table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

Starting from Nim v0.20, tables are initialized by default and it is not necessary to call this function explicitly.

See also:

Examples:

let
  a = initOrderedTable[int, string]()
  b = initOrderedTable[char, seq[int]]()
  Source Edit
proc toOrderedTable[A, B](pairs: openArray[(A, B)]): OrderedTable[A, B]

Creates a new ordered hash table that contains the given pairs.

pairs is a container consisting of (key, value) tuples.

See also:

Examples:

let a = [('a', 5), ('b', 9)]
let b = toOrderedTable(a)
assert b == {'a': 5, 'b': 9}.toOrderedTable
  Source Edit
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 proc whether the key exists.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert a['a'] == 5
doAssertRaises(KeyError):
  echo a['z']
  Source Edit
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 KeyError exception is raised.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table
  Source Edit
proc `[]=`[A, B](t: var OrderedTable[A, B]; key: A; val: B)

Inserts a (key, value) pair into t.

See also:

Examples:

var a = initOrderedTable[char, int]()
a['x'] = 7
a['y'] = 33
doAssert a == {'x': 7, 'y': 33}.toOrderedTable
  Source Edit
proc hasKey[A, B](t: OrderedTable[A, B]; key: A): bool

Returns true if key is in the table t.

See also:

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert a.hasKey('a') == true
doAssert a.hasKey('z') == false
  Source Edit
proc contains[A, B](t: OrderedTable[A, B]; key: A): bool
Alias of hasKey proc for use with the in operator.

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert 'b' in a == true
doAssert a.contains('z') == false
  Source Edit
proc hasKeyOrPut[A, B](t: var OrderedTable[A, B]; key: A; val: B): bool

Returns true if key is in the table, otherwise inserts value.

See also:

Examples:

var a = {'a': 5, 'b': 9}.toOrderedTable
if a.hasKeyOrPut('a', 50):
  a['a'] = 99
if a.hasKeyOrPut('z', 50):
  a['z'] = 99
doAssert a == {'a': 99, 'b': 9, 'z': 50}.toOrderedTable
  Source Edit
proc getOrDefault[A, B](t: OrderedTable[A, B]; key: A): B

Retrieves the value at t[key] if key is in t. Otherwise, the default initialization value for type B is returned (e.g. 0 for any integer type).

See also:

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert a.getOrDefault('a') == 5
doAssert a.getOrDefault('z') == 0
  Source Edit
proc getOrDefault[A, B](t: OrderedTable[A, B]; key: A; default: B): B

Retrieves the value at t[key] if key is in t. Otherwise, default is returned.

See also:

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert a.getOrDefault('a', 99) == 5
doAssert a.getOrDefault('z', 99) == 99
  Source Edit
proc mgetOrPut[A, B](t: var OrderedTable[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.

See also:

Examples:

var a = {'a': 5, 'b': 9}.toOrderedTable
doAssert a.mgetOrPut('a', 99) == 5
doAssert a.mgetOrPut('z', 99) == 99
doAssert a == {'a': 5, 'b': 9, 'z': 99}.toOrderedTable
  Source Edit
proc len[A, B](t: OrderedTable[A, B]): int {...}{.inline.}
Returns the number of keys in t.

Examples:

let a = {'a': 5, 'b': 9}.toOrderedTable
doAssert len(a) == 2
  Source Edit
proc add[A, B](t: var OrderedTable[A, B]; key: A; val: B)

Puts a new (key, value) pair into t even if t[key] already exists.

This can introduce duplicate keys into the table!

Use []= proc for inserting a new (key, value) pair in the table without introducing duplicates.

  Source Edit
proc del[A, B](t: var OrderedTable[A, B]; key: A)

Deletes key from hash table t. Does nothing if the key does not exist.

O(n) complexity.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.toOrderedTable
a.del('a')
doAssert a == {'b': 9, 'c': 13}.toOrderedTable
a.del('z')
doAssert a == {'b': 9, 'c': 13}.toOrderedTable
  Source Edit
proc clear[A, B](t: var OrderedTable[A, B])

Resets the table so that it is empty.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.toOrderedTable
doAssert len(a) == 3
clear(a)
doAssert len(a) == 0
  Source Edit
proc sort[A, B](t: var OrderedTable[A, B]; cmp: proc (x, y: (A, B)): int;
              order = SortOrder.Ascending)

Sorts t according to the function cmp.

This modifies the internal list that kept the insertion order, so insertion order is lost after this call but key lookup and insertions remain possible after sort (in contrast to the sort proc for count tables).

Examples:

import
  algorithm

var a = initOrderedTable[char, int]()
for i, c in "cab":
  a[c] = 10 * i
doAssert a == {'c': 0, 'a': 10, 'b': 20}.toOrderedTable
a.sort(system.cmp)
doAssert a == {'a': 10, 'b': 20, 'c': 0}.toOrderedTable
a.sort(system.cmp, order = SortOrder.Descending)
doAssert a == {'c': 0, 'b': 20, 'a': 10}.toOrderedTable
  Source Edit
proc `$`[A, B](t: OrderedTable[A, B]): string
The $ operator for ordered hash tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A, B](s, t: OrderedTable[A, B]): bool
The == operator for ordered hash tables. Returns true if both the content and the order are equal.

Examples:

let
  a = {'a': 5, 'b': 9, 'c': 13}.toOrderedTable
  b = {'b': 9, 'c': 13, 'a': 5}.toOrderedTable
doAssert a != b
  Source Edit
proc newOrderedTable[A, B](initialsize = defaultInitialSize): <//>OrderedTableRef[A, B]

Creates a new ordered ref hash table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

See also:

Examples:

let
  a = newOrderedTable[int, string]()
  b = newOrderedTable[char, seq[int]]()
  Source Edit
proc newOrderedTable[A, B](pairs: openArray[(A, B)]): <//>OrderedTableRef[A, B]

Creates a new ordered ref hash table that contains the given pairs.

pairs is a container consisting of (key, value) tuples.

See also:

Examples:

let a = [('a', 5), ('b', 9)]
let b = newOrderedTable(a)
assert b == {'a': 5, 'b': 9}.newOrderedTable
  Source Edit
proc `[]`[A, B](t: OrderedTableRef[A, B]; key: A): var B

Retrieves the value at t[key].

If key is not in t, the KeyError exception is raised. One can check with hasKey proc whether the key exists.

See also:

  • getOrDefault proc to return a default value (e.g. zero for int) if the key doesn't exist
  • getOrDefault proc to return a custom value if the key doesn't exist
  • []= proc for inserting a new (key, value) pair in the table
  • hasKey proc for checking if a key is in the table

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert a['a'] == 5
doAssertRaises(KeyError):
  echo a['z']
  Source Edit
proc `[]=`[A, B](t: OrderedTableRef[A, B]; key: A; val: B)

Inserts a (key, value) pair into t.

See also:

Examples:

var a = newOrderedTable[char, int]()
a['x'] = 7
a['y'] = 33
doAssert a == {'x': 7, 'y': 33}.newOrderedTable
  Source Edit
proc hasKey[A, B](t: OrderedTableRef[A, B]; key: A): bool

Returns true if key is in the table t.

See also:

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert a.hasKey('a') == true
doAssert a.hasKey('z') == false
  Source Edit
proc contains[A, B](t: OrderedTableRef[A, B]; key: A): bool
Alias of hasKey proc for use with the in operator.

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert 'b' in a == true
doAssert a.contains('z') == false
  Source Edit
proc hasKeyOrPut[A, B](t: var OrderedTableRef[A, B]; key: A; val: B): bool

Returns true if key is in the table, otherwise inserts value.

See also:

Examples:

var a = {'a': 5, 'b': 9}.newOrderedTable
if a.hasKeyOrPut('a', 50):
  a['a'] = 99
if a.hasKeyOrPut('z', 50):
  a['z'] = 99
doAssert a == {'a': 99, 'b': 9, 'z': 50}.newOrderedTable
  Source Edit
proc getOrDefault[A, B](t: OrderedTableRef[A, B]; key: A): B

Retrieves the value at t[key] if key is in t. Otherwise, the default initialization value for type B is returned (e.g. 0 for any integer type).

See also:

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert a.getOrDefault('a') == 5
doAssert a.getOrDefault('z') == 0
  Source Edit
proc getOrDefault[A, B](t: OrderedTableRef[A, B]; key: A; default: B): B

Retrieves the value at t[key] if key is in t. Otherwise, default is returned.

See also:

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert a.getOrDefault('a', 99) == 5
doAssert a.getOrDefault('z', 99) == 99
  Source Edit
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.

See also:

Examples:

var a = {'a': 5, 'b': 9}.newOrderedTable
doAssert a.mgetOrPut('a', 99) == 5
doAssert a.mgetOrPut('z', 99) == 99
doAssert a == {'a': 5, 'b': 9, 'z': 99}.newOrderedTable
  Source Edit
proc len[A, B](t: OrderedTableRef[A, B]): int {...}{.inline.}
Returns the number of keys in t.

Examples:

let a = {'a': 5, 'b': 9}.newOrderedTable
doAssert len(a) == 2
  Source Edit
proc add[A, B](t: OrderedTableRef[A, B]; key: A; val: B)

Puts a new (key, value) pair into t even if t[key] already exists.

This can introduce duplicate keys into the table!

Use []= proc for inserting a new (key, value) pair in the table without introducing duplicates.

  Source Edit
proc del[A, B](t: var OrderedTableRef[A, B]; key: A)

Deletes key from hash table t. Does nothing if the key does not exist.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.newOrderedTable
a.del('a')
doAssert a == {'b': 9, 'c': 13}.newOrderedTable
a.del('z')
doAssert a == {'b': 9, 'c': 13}.newOrderedTable
  Source Edit
proc clear[A, B](t: var OrderedTableRef[A, B])

Resets the table so that it is empty.

See also:

Examples:

var a = {'a': 5, 'b': 9, 'c': 13}.newOrderedTable
doAssert len(a) == 3
clear(a)
doAssert len(a) == 0
  Source Edit
proc sort[A, B](t: OrderedTableRef[A, B]; cmp: proc (x, y: (A, B)): int;
              order = SortOrder.Ascending)

Sorts t according to the function cmp.

This modifies the internal list that kept the insertion order, so insertion order is lost after this call but key lookup and insertions remain possible after sort (in contrast to the sort proc for count tables).

Examples:

import
  algorithm

var a = newOrderedTable[char, int]()
for i, c in "cab":
  a[c] = 10 * i
doAssert a == {'c': 0, 'a': 10, 'b': 20}.newOrderedTable
a.sort(system.cmp)
doAssert a == {'a': 10, 'b': 20, 'c': 0}.newOrderedTable
a.sort(system.cmp, order = SortOrder.Descending)
doAssert a == {'c': 0, 'b': 20, 'a': 10}.newOrderedTable
  Source Edit
proc `$`[A, B](t: OrderedTableRef[A, B]): string
The $ operator for hash tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A, B](s, t: OrderedTableRef[A, B]): bool
The == operator for ordered hash tables. Returns true if either both tables are nil, or neither is nil and the content and the order of both are equal.

Examples:

let
  a = {'a': 5, 'b': 9, 'c': 13}.newOrderedTable
  b = {'b': 9, 'c': 13, 'a': 5}.newOrderedTable
doAssert a != b
  Source Edit
proc initCountTable[A](initialsize = defaultInitialSize): CountTable[A]

Creates a new count table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

Starting from Nim v0.20, tables are initialized by default and it is not necessary to call this function explicitly.

See also:

  Source Edit
proc toCountTable[A](keys: openArray[A]): CountTable[A]
Creates a new count table with every member of a container keys having a count of how many times it occurs in that container.   Source Edit
proc `[]`[A](t: CountTable[A]; key: A): int

Retrieves the value at t[key] if key is in t. Otherwise 0 is returned.

See also:

  Source Edit
proc mget[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.

  Source Edit
proc `[]=`[A](t: var CountTable[A]; key: A; val: int)

Inserts a (key, value) pair into t.

See also:

  • [] proc for retrieving a value of a key
  • inc proc for incrementing a value of a key
  Source Edit
proc inc[A](t: var CountTable[A]; key: A; val = 1)
Increments t[key] by val (default: 1).

Examples:

var a = toCountTable("aab")
a.inc('a')
a.inc('b', 10)
doAssert a == toCountTable("aaabbbbbbbbbbb")
  Source Edit
proc smallest[A](t: CountTable[A]): tuple[key: A, val: int]

Returns the (key, value) pair with the smallest val. Efficiency: O(n)

See also:

  Source Edit
proc largest[A](t: CountTable[A]): tuple[key: A, val: int]

Returns the (key, value) pair with the largest val. Efficiency: O(n)

See also:

  Source Edit
proc hasKey[A](t: CountTable[A]; key: A): bool

Returns true if key is in the table t.

See also:

  Source Edit
proc contains[A](t: CountTable[A]; key: A): bool
Alias of hasKey proc for use with the in operator.   Source Edit
proc getOrDefault[A](t: CountTable[A]; key: A; default: int = 0): int

Retrieves the value at t[key] if``key`` is in t. Otherwise, the integer value of default is returned.

See also:

  • [] proc for retrieving a value of a key
  • hasKey proc for checking if a key is in the table
  Source Edit
proc len[A](t: CountTable[A]): int
Returns the number of keys in t.   Source Edit
proc clear[A](t: var CountTable[A])
Resets the table so that it is empty.   Source Edit
proc sort[A](t: var CountTable[A]; order = SortOrder.Descending)

Sorts the count table so that, by default, the entry with the highest counter comes first.

WARNING: This is destructive! Once sorted, you must not modify t afterwards!

You can use the iterators pairs, keys, and values to iterate over t in the sorted order.

Examples:

import
  algorithm, sequtils

var a = toCountTable("abracadabra")
doAssert a == "aaaaabbrrcd".toCountTable
a.sort()
doAssert toSeq(a.values) == @[5, 2, 2, 1, 1]
a.sort(SortOrder.Ascending)
doAssert toSeq(a.values) == @[1, 1, 2, 2, 5]
  Source Edit
proc merge[A](s: var CountTable[A]; t: CountTable[A])
Merges the second table into the first one (must be declared as var).

Examples:

var a = toCountTable("aaabbc")
let b = toCountTable("bcc")
a.merge(b)
doAssert a == toCountTable("aaabbbccc")
  Source Edit
proc merge[A](s, t: CountTable[A]): CountTable[A]
Merges the two tables into a new one.

Examples:

let
  a = toCountTable("aaabbc")
  b = toCountTable("bcc")
doAssert merge(a, b) == toCountTable("aaabbbccc")
  Source Edit
proc `$`[A](t: CountTable[A]): string
The $ operator for count tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A](s, t: CountTable[A]): bool
The == operator for count tables. Returns true if both tables contain the same keys with the same count. Insert order does not matter.   Source Edit
proc newCountTable[A](initialsize = defaultInitialSize): <//>CountTableRef[A]

Creates a new ref count table that is empty.

initialSize must be a power of two (default: 64). If you need to accept runtime values for this you could use the nextPowerOfTwo proc from the math module or the rightSize proc from this module.

See also:

  Source Edit
proc newCountTable[A](keys: openArray[A]): <//>CountTableRef[A]
Creates a new ref count table with every member of a container keys having a count of how many times it occurs in that container.   Source Edit
proc `[]`[A](t: CountTableRef[A]; key: A): int

Retrieves the value at t[key] if key is in t. Otherwise 0 is returned.

See also:

  Source Edit
proc mget[A](t: CountTableRef[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.

  Source Edit
proc `[]=`[A](t: CountTableRef[A]; key: A; val: int)

Inserts a (key, value) pair into t.

See also:

  • [] proc for retrieving a value of a key
  • inc proc for incrementing a value of a key
  Source Edit
proc inc[A](t: CountTableRef[A]; key: A; val = 1)
Increments t[key] by val (default: 1).

Examples:

var a = newCountTable("aab")
a.inc('a')
a.inc('b', 10)
doAssert a == newCountTable("aaabbbbbbbbbbb")
  Source Edit
proc smallest[A](t: CountTableRef[A]): (A, int)

Returns the (key, value) pair with the smallest val. Efficiency: O(n)

See also:

  Source Edit
proc largest[A](t: CountTableRef[A]): (A, int)

Returns the (key, value) pair with the largest val. Efficiency: O(n)

See also:

  Source Edit
proc hasKey[A](t: CountTableRef[A]; key: A): bool

Returns true if key is in the table t.

See also:

  Source Edit
proc contains[A](t: CountTableRef[A]; key: A): bool
Alias of hasKey proc for use with the in operator.   Source Edit
proc getOrDefault[A](t: CountTableRef[A]; key: A; default: int): int

Retrieves the value at t[key] if``key`` is in t. Otherwise, the integer value of default is returned.

See also:

  • [] proc for retrieving a value of a key
  • hasKey proc for checking if a key is in the table
  Source Edit
proc len[A](t: CountTableRef[A]): int
Returns the number of keys in t.   Source Edit
proc clear[A](t: CountTableRef[A])
Resets the table so that it is empty.   Source Edit
proc sort[A](t: CountTableRef[A]; order = SortOrder.Descending)

Sorts the count table so that, by default, 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.

  Source Edit
proc merge[A](s, t: CountTableRef[A])
Merges the second table into the first one.

Examples:

let
  a = newCountTable("aaabbc")
  b = newCountTable("bcc")
a.merge(b)
doAssert a == newCountTable("aaabbbccc")
  Source Edit
proc `$`[A](t: CountTableRef[A]): string
The $ operator for count tables. Used internally when calling echo on a table.   Source Edit
proc `==`[A](s, t: CountTableRef[A]): bool
The == operator for count tables. Returns true if either both tables are nil, or neither is nil and both contain the same keys with the same count. Insert order does not matter.   Source Edit

Iterators

iterator pairs[A, B](t: Table[A, B]): (A, B)

Iterates over any (key, value) pair in the table t.

See also:

Examples:

let a = {
  'o': [1, 5, 7, 9],
  'e': [2, 4, 6, 8]
  }.toTable

for k, v in a.pairs:
  echo "key: ", k
  echo "value: ", v

# key: e
# value: [2, 4, 6, 8]
# key: o
# value: [1, 5, 7, 9]
  Source Edit
iterator mpairs[A, B](t: var Table[A, B]): (A, var B)

Iterates over any (key, value) pair in the table t (must be declared as var). The values can be modified.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toTable
for k, v in a.mpairs:
  v.add(v[0] + 10)
doAssert a == {'e': @[2, 4, 6, 8, 12], 'o': @[1, 5, 7, 9, 11]}.toTable
  Source Edit
iterator keys[A, B](t: Table[A, B]): A

Iterates over any key in the table t.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toTable
for k in a.keys:
  a[k].add(99)
doAssert a == {'e': @[2, 4, 6, 8, 99], 'o': @[1, 5, 7, 9, 99]}.toTable
  Source Edit
iterator values[A, B](t: Table[A, B]): B

Iterates over any value in the table t.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toTable
for v in a.values:
  doAssert v.len == 4
  Source Edit
iterator mvalues[A, B](t: var Table[A, B]): var B

Iterates over any value in the table t (must be declared as var). The values can be modified.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toTable
for v in a.mvalues:
  v.add(99)
doAssert a == {'e': @[2, 4, 6, 8, 99], 'o': @[1, 5, 7, 9, 99]}.toTable
  Source Edit
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.

Used if you have a table with duplicate keys (as a result of using add proc).

Examples:

var a = {'a': 3, 'b': 5}.toTable
for i in 1..3:
  a.add('z', 10*i)
echo a # {'a': 3, 'b': 5, 'z': 10, 'z': 20, 'z': 30}

for v in a.allValues('z'):
  echo v
# 10
# 20
# 30
  Source Edit
iterator pairs[A, B](t: TableRef[A, B]): (A, B)

Iterates over any (key, value) pair in the table t.

See also:

Examples:

let a = {
  'o': [1, 5, 7, 9],
  'e': [2, 4, 6, 8]
  }.newTable

for k, v in a.pairs:
  echo "key: ", k
  echo "value: ", v

# key: e
# value: [2, 4, 6, 8]
# key: o
# value: [1, 5, 7, 9]
  Source Edit
iterator mpairs[A, B](t: TableRef[A, B]): (A, var B)

Iterates over any (key, value) pair in the table t. The values can be modified.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newTable
for k, v in a.mpairs:
  v.add(v[0] + 10)
doAssert a == {'e': @[2, 4, 6, 8, 12], 'o': @[1, 5, 7, 9, 11]}.newTable
  Source Edit
iterator keys[A, B](t: TableRef[A, B]): A

Iterates over any key in the table t.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newTable
for k in a.keys:
  a[k].add(99)
doAssert a == {'e': @[2, 4, 6, 8, 99], 'o': @[1, 5, 7, 9, 99]}.newTable
  Source Edit
iterator values[A, B](t: TableRef[A, B]): B

Iterates over any value in the table t.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newTable
for v in a.values:
  doAssert v.len == 4
  Source Edit
iterator mvalues[A, B](t: TableRef[A, B]): var B

Iterates over any value in the table t. The values can be modified.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newTable
for v in a.mvalues:
  v.add(99)
doAssert a == {'e': @[2, 4, 6, 8, 99], 'o': @[1, 5, 7, 9, 99]}.newTable
  Source Edit
iterator pairs[A, B](t: OrderedTable[A, B]): (A, B)

Iterates over any (key, value) pair in the table t in insertion order.

See also:

Examples:

let a = {
  'o': [1, 5, 7, 9],
  'e': [2, 4, 6, 8]
  }.toOrderedTable

for k, v in a.pairs:
  echo "key: ", k
  echo "value: ", v

# key: o
# value: [1, 5, 7, 9]
# key: e
# value: [2, 4, 6, 8]
  Source Edit
iterator mpairs[A, B](t: var OrderedTable[A, B]): (A, var B)

Iterates over any (key, value) pair in the table t (must be declared as var) in insertion order. The values can be modified.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toOrderedTable
for k, v in a.mpairs:
  v.add(v[0] + 10)
doAssert a == {'o': @[1, 5, 7, 9, 11], 'e': @[2, 4, 6, 8, 12]}.toOrderedTable
  Source Edit
iterator keys[A, B](t: OrderedTable[A, B]): A

Iterates over any key in the table t in insertion order.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toOrderedTable
for k in a.keys:
  a[k].add(99)
doAssert a == {'o': @[1, 5, 7, 9, 99], 'e': @[2, 4, 6, 8, 99]}.toOrderedTable
  Source Edit
iterator values[A, B](t: OrderedTable[A, B]): B

Iterates over any value in the table t in insertion order.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toOrderedTable
for v in a.values:
  doAssert v.len == 4
  Source Edit
iterator mvalues[A, B](t: var OrderedTable[A, B]): var B

Iterates over any value in the table t (must be declared as var) in insertion order. The values can be modified.

See also:

Examples:

var a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.toOrderedTable
for v in a.mvalues:
  v.add(99)
doAssert a == {'o': @[1, 5, 7, 9, 99], 'e': @[2, 4, 6, 8, 99]}.toOrderedTable
  Source Edit
iterator pairs[A, B](t: OrderedTableRef[A, B]): (A, B)

Iterates over any (key, value) pair in the table t in insertion order.

See also:

Examples:

let a = {
  'o': [1, 5, 7, 9],
  'e': [2, 4, 6, 8]
  }.newOrderedTable

for k, v in a.pairs:
  echo "key: ", k
  echo "value: ", v

# key: o
# value: [1, 5, 7, 9]
# key: e
# value: [2, 4, 6, 8]
  Source Edit
iterator mpairs[A, B](t: OrderedTableRef[A, B]): (A, var B)

Iterates over any (key, value) pair in the table t in insertion order. The values can be modified.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newOrderedTable
for k, v in a.mpairs:
  v.add(v[0] + 10)
doAssert a == {'o': @[1, 5, 7, 9, 11], 'e': @[2, 4, 6, 8, 12]}.newOrderedTable
  Source Edit
iterator keys[A, B](t: OrderedTableRef[A, B]): A

Iterates over any key in the table t in insertion order.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newOrderedTable
for k in a.keys:
  a[k].add(99)
doAssert a == {'o': @[1, 5, 7, 9, 99], 'e': @[2, 4, 6, 8, 99]}.newOrderedTable
  Source Edit
iterator values[A, B](t: OrderedTableRef[A, B]): B

Iterates over any value in the table t in insertion order.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newOrderedTable
for v in a.values:
  doAssert v.len == 4
  Source Edit
iterator mvalues[A, B](t: OrderedTableRef[A, B]): var B

Iterates over any value in the table t in insertion order. The values can be modified.

See also:

Examples:

let a = {'o': @[1, 5, 7, 9], 'e': @[2, 4, 6, 8]}.newOrderedTable
for v in a.mvalues:
  v.add(99)
doAssert a == {'o': @[1, 5, 7, 9, 99], 'e': @[2, 4, 6, 8, 99]}.newOrderedTable
  Source Edit
iterator pairs[A](t: CountTable[A]): (A, int)

Iterates over any (key, value) pair in the table t.

See also:

Examples:

let a = toCountTable("abracadabra")

for k, v in pairs(a):
  echo "key: ", k
  echo "value: ", v

# key: a
# value: 5
# key: b
# value: 2
# key: c
# value: 1
# key: d
# value: 1
# key: r
# value: 2
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iterator mpairs[A](t: var CountTable[A]): (A, var int)

Iterates over any (key, value) pair in the table t (must be declared as var). The values can be modified.

See also:

Examples:

var a = toCountTable("abracadabra")
for k, v in mpairs(a):
  v = 2
doAssert a == toCountTable("aabbccddrr")
  Source Edit
iterator keys[A](t: CountTable[A]): A

Iterates over any key in the table t.

See also:

Examples:

var a = toCountTable("abracadabra")
for k in keys(a):
  a[k] = 2
doAssert a == toCountTable("aabbccddrr")
  Source Edit
iterator values[A](t: CountTable[A]): int

Iterates over any value in the table t.

See also:

Examples:

let a = toCountTable("abracadabra")
for v in values(a):
  assert v < 10
  Source Edit
iterator mvalues[A](t: var CountTable[A]): var int

Iterates over any value in the table t (must be declared as var). The values can be modified.

See also:

Examples:

var a = toCountTable("abracadabra")
for v in mvalues(a):
  v = 2
doAssert a == toCountTable("aabbccddrr")
  Source Edit
iterator pairs[A](t: CountTableRef[A]): (A, int)

Iterates over any (key, value) pair in the table t.

See also:

Examples:

let a = newCountTable("abracadabra")

for k, v in pairs(a):
  echo "key: ", k
  echo "value: ", v

# key: a
# value: 5
# key: b
# value: 2
# key: c
# value: 1
# key: d
# value: 1
# key: r
# value: 2
  Source Edit
iterator mpairs[A](t: CountTableRef[A]): (A, var int)

Iterates over any (key, value) pair in the table t. The values can be modified.

See also:

Examples:

let a = newCountTable("abracadabra")
for k, v in mpairs(a):
  v = 2
doAssert a == newCountTable("aabbccddrr")
  Source Edit
iterator keys[A](t: CountTableRef[A]): A

Iterates over any key in the table t.

See also:

Examples:

let a = newCountTable("abracadabra")
for k in keys(a):
  a[k] = 2
doAssert a == newCountTable("aabbccddrr")
  Source Edit
iterator values[A](t: CountTableRef[A]): int

Iterates over any value in the table t.

See also:

Examples:

let a = newCountTable("abracadabra")
for v in values(a):
  assert v < 10
  Source Edit
iterator mvalues[A](t: CountTableRef[A]): var int

Iterates over any value in the table t. The values can be modified.

See also:

Examples:

var a = newCountTable("abracadabra")
for v in mvalues(a):
  v = 2
doAssert a == newCountTable("aabbccddrr")
  Source Edit

Templates

template withValue[A; B](t: var Table[A, B]; key: A; value, body: untyped)

Retrieves the value at t[key].

value can be modified in the scope of the withValue call.

sharedTable.withValue(key, value) do:
  # block is executed only if ``key`` in ``t``
  value.name = "username"
  value.uid = 1000
  Source Edit
template withValue[A; B](t: var Table[A, B]; key: A; value, body1, body2: untyped)

Retrieves the value at t[key].

value can be modified in the scope of the withValue call.

table.withValue(key, value) do:
  # block is executed only if ``key`` in ``t``
  value.name = "username"
  value.uid = 1000
do:
  # block is executed when ``key`` not in ``t``
  raise newException(KeyError, "Key not found")
  Source Edit