Package 'intmap'

Title: Ordered Containers with Integer Keys
Description: Provides a key-value store data structure. The keys are integers and the values can be any R object. This is like a list but indexed by a set of integers, not necessarily contiguous and possibly negative. The implementation uses a 'R6' class. These containers are not faster than lists but their usage can be more convenient for certain situations.
Authors: Stéphane Laurent
Maintainer: Stéphane Laurent <[email protected]>
License: GPL-3
Version: 1.0.0
Built: 2026-06-04 08:36:35 UTC
Source: https://github.com/stla/intmap

Help Index

R6 class representing an ordered map

Description

A map is given by keys and values.

Methods

Public methods

Method new()

Creates a new intmap object.

Usage
intmap$new(keys = NULL, values)
Arguments
keys

keys, an integer vector without NA value

values

values, a list of R objects; keys and values must have the same length

Returns

An intmap object.

Examples
intmap$new() # empty map
intmap$new(
  keys = c(4, -2), 
  values = list(c(1, 2), c("a", "b", "c"))
)
# examples with duplicated keys:
intmap$new(
  keys = c(1, 1, 5), 
  values = list(c(1, 2), c(3, 4), "x")
)

Method print()

Show instance of an intmap object.

Usage
intmap$print(...)
Arguments
...

ignored

Method size()

Size of the reference map.

Usage
intmap$size()
Returns

An integer, the number of entries.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$size()

Method keys()

Get all keys.

Usage
intmap$keys()
Returns

The keys, an integer vector.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$keys()

Method values()

Get all values.

Usage
intmap$values()
Returns

The values, a list of R objects.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$values()

Method items()

Get all entries of the reference map.

Usage
intmap$items()
Returns

The entries in a dataframe.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$items()

Method toList()

Converts the map to a named list.

Usage
intmap$toList()
Returns

A named list (the names are the keys).

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$toList()

Method at()

Returns the 'maybe' value corresponding to the given key.

Usage
intmap$at(key)
Arguments
key

a key (integer)

Returns

A maybe value, either the value corresponding to the key as a 'Just' maybe value if the key is found, otherwise the 'Nothing' maybe value.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$at(11)
from_just(imap$at(11))
imap$at(4)

Method get()

Get the value corresponding to the given key or a default value if this key is missing.

Usage
intmap$get(key, default = NULL)
Arguments
key

a key (integer)

default

a R object, the default value

Returns

Either the value corresponding to the key if the key is found, otherwise the default value.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$get(11, default = 999)
imap$get(4, default = 999)

Method index()

Returns the index of the given key.

Usage
intmap$index(key)
Arguments
key

a key (integer)

Returns

The index of the key, or NA if it is not found.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$index(11)
imap$index(4)

Method extract()

Extract a submap from the reference map.

Usage
intmap$extract(keys, inplace = FALSE, bydeleting = FALSE)
Arguments
keys

some keys, an integer vector; those which do not belong to the keys of the reference map will be ignored

inplace

Boolean, whether to update the reference map or to return a new map

bydeleting

Boolean, whether to construct the submap by deleting the keys which are not in keys or by starting from the empty submap and adding the entries

Returns

An intmap object if inplace=FALSE, otherwise the updated reference map, invisibly.

Examples
imap <- intmap$new(
  keys = c(11, -2, 3), values = list(c("a", "b"), list(3, 4, 5), "X")
)
imap_copy <- imap$copy()
imap$extract(c(11, 3))
imap
imap$extract(c(11, 3), inplace = TRUE)
imap
imap_copy$extract(c(11, 3), bydeleting = TRUE)
imap_copy
imap_copy$extract(c(11, 3), inplace = TRUE, bydeleting = TRUE)
imap_copy

Method has_key()

Checks whether a key exists in the reference map.

Usage
intmap$has_key(key)
Arguments
key

a key (integer)

Returns

A Boolean value.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$has_key(11)
imap$has_key(1)

Method nth()

Returns the n-th entry of the reference map.

Usage
intmap$nth(n, stop_if_too_large = TRUE)
Arguments
n

index, a positive integer

stop_if_too_large

a Boolean value, whether to stop if n is too large, or to use maybe values

Returns

A list with the key and the value at index n if stop_if_too_large=TRUE and n is not too large, otherwise a maybe value: either this list wrapped in a 'Just' container, or 'Nothing'.

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$nth(2)
imap$nth(2, stop_if_too_large = FALSE)
imap$nth(9, stop_if_too_large = FALSE)

Method insert()

Insert a new entry in the reference map.

Usage
intmap$insert(key, value, replace = FALSE)
Arguments
key

a key (integer)

value

a value (R object)

replace

Boolean, whether to replace the value if the key is already present

Returns

This updates the reference map and this returns a Boolean value: if replace=FALSE, this returns TRUE if the value has been inserted (i.e. the given key is new); similarly, if replace=TRUE, this returns TRUE if the given key is new (so FALSE means that the value of the existing key has been replaced).

Examples
imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$insert(3, c(6, 7)) # TRUE (insertion)
imap
imap$insert(11, c(8, 9)) # FALSE (no change)
imap
imap$insert(11, c(8, 9), replace = TRUE) # FALSE (replacement)
imap

Method erase()

Erase the entries of the reference map whose keys are the given ones.

Usage
intmap$erase(keys)
Arguments
keys

some keys, an integer vector; those which do not belong to the keys of the reference map are ignored

Returns

The reference map, invisibly.

Examples
imap <- intmap$new(
  keys = c(11, -2, 3), values = list(c("a", "b"), list(3, 4, 5), "X")
)
imap$erase(11)
imap
imap$erase(c(-2, 3))
imap

Method merge()

Merge the reference map with another map.

Usage
intmap$merge(map)
Arguments
map

an intmap object

Returns

The updated reference map, invisibly. Keys of map that are also keys of the reference map are ignored, i.e. there is no replacement, only insertions.

Examples
imap1 <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap2 <- intmap$new(
  keys = c(11, 3), values = list("X", "Z")
)
imap1$merge(imap2)
imap1

Method copy()

Copy the reference map.

Usage
intmap$copy()
Returns

A copy of the reference map.

Examples
imap <- intmap$new(
  keys = c(11, 3), values = list(TRUE, "Z")
)
true_copy <- imap$copy()
true_copy$erase(11)
imap
naive_copy <- imap
naive_copy$erase(11)
imap

Examples

## ------------------------------------------------
## Method `intmap$new`
## ------------------------------------------------

intmap$new() # empty map
intmap$new(
  keys = c(4, -2), 
  values = list(c(1, 2), c("a", "b", "c"))
)
# examples with duplicated keys:
intmap$new(
  keys = c(1, 1, 5), 
  values = list(c(1, 2), c(3, 4), "x")
)

## ------------------------------------------------
## Method `intmap$size`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$size()

## ------------------------------------------------
## Method `intmap$keys`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$keys()

## ------------------------------------------------
## Method `intmap$values`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$values()

## ------------------------------------------------
## Method `intmap$items`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$items()

## ------------------------------------------------
## Method `intmap$toList`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$toList()

## ------------------------------------------------
## Method `intmap$at`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$at(11)
from_just(imap$at(11))
imap$at(4)

## ------------------------------------------------
## Method `intmap$get`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$get(11, default = 999)
imap$get(4, default = 999)

## ------------------------------------------------
## Method `intmap$index`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$index(11)
imap$index(4)

## ------------------------------------------------
## Method `intmap$extract`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2, 3), values = list(c("a", "b"), list(3, 4, 5), "X")
)
imap_copy <- imap$copy()
imap$extract(c(11, 3))
imap
imap$extract(c(11, 3), inplace = TRUE)
imap
imap_copy$extract(c(11, 3), bydeleting = TRUE)
imap_copy
imap_copy$extract(c(11, 3), inplace = TRUE, bydeleting = TRUE)
imap_copy

## ------------------------------------------------
## Method `intmap$has_key`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$has_key(11)
imap$has_key(1)

## ------------------------------------------------
## Method `intmap$nth`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$nth(2)
imap$nth(2, stop_if_too_large = FALSE)
imap$nth(9, stop_if_too_large = FALSE)

## ------------------------------------------------
## Method `intmap$insert`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap$insert(3, c(6, 7)) # TRUE (insertion)
imap
imap$insert(11, c(8, 9)) # FALSE (no change)
imap
imap$insert(11, c(8, 9), replace = TRUE) # FALSE (replacement)
imap

## ------------------------------------------------
## Method `intmap$erase`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, -2, 3), values = list(c("a", "b"), list(3, 4, 5), "X")
)
imap$erase(11)
imap
imap$erase(c(-2, 3))
imap

## ------------------------------------------------
## Method `intmap$merge`
## ------------------------------------------------

imap1 <- intmap$new(
  keys = c(11, -2), values = list(c("a", "b"), list(3, 4, 5))
)
imap2 <- intmap$new(
  keys = c(11, 3), values = list("X", "Z")
)
imap1$merge(imap2)
imap1

## ------------------------------------------------
## Method `intmap$copy`
## ------------------------------------------------

imap <- intmap$new(
  keys = c(11, 3), values = list(TRUE, "Z")
)
true_copy <- imap$copy()
true_copy$erase(11)
imap
naive_copy <- imap
naive_copy$erase(11)
imap

Extract value from a 'Just' value

Description

The from_just function is imported from the maybe package. Follow the link to its documentation: from_just. It has been imported for convenient use of the intmap$at method, which returns a 'Just' value.