Dict Class

The Dict() resembles Python's dict type, and is implemented as a specialized associative Container(). For the standard S3 interface, see dict().

Details

This class inherits from class Container() and overwrides some methods to account for the associative key-value pair semantic. Internally, all key-value pairs are stored in a hash-table and the elements are always sorted lexicographically by their keys.

See also

Container(), dict()

Super classes

container::Iterable -> container::Container -> Dict

Methods

Public methods

• Dict$new()

• Dict$add()

• Dict$discard_at()

• Dict$get()

• Dict$keys()

• Dict$remove()

• Dict$replace()

• Dict$set()

• Dict$sort()

• Dict$update()

• Dict$values()

• Dict$clone()

Inherited methods

• container::Iterable$iter()
• container::Container$at()
• container::Container$at2()
• container::Container$clear()
• container::Container$count()
• container::Container$delete()
• container::Container$delete_at()
• container::Container$discard()
• container::Container$empty()
• container::Container$get_compare_fun()
• container::Container$has()
• container::Container$has_name()
• container::Container$is_empty()
• container::Container$length()
• container::Container$names()
• container::Container$peek_at()
• container::Container$peek_at2()
• container::Container$pop()
• container::Container$print()
• container::Container$rename()
• container::Container$replace_at()
• container::Container$size()
• container::Container$type()

---

Method new()

Dict constructor

Usage

Dict$new(...)

Arguments

...

initial elements put into the Dict

Returns

returns the Dict

---

Method add()

If name not yet in Dict, insert value at name, otherwise signal an error.

Usage

Dict$add(name, value)

Arguments

name

character variable name under which to store value.

value

the value to be added to the Dict.

Returns

the Dict object

---

Method discard_at()

Discard value at given index. If index is not found, the operation is ignored.

Usage

Dict$discard_at(index)

Arguments

index

character or numeric index

Returns

the Dict object

---

Method get()

This function is deprecated. Use at2() instead.

Usage

Dict$get(key)

Arguments

key

character name of key.

Returns

If key in Dict, return value at key, else throw error.

---

Method keys()

Get all keys.

Usage

Dict$keys()

Returns

character vector of all keys.

---

Method remove()

This function is deprecated. Use delete() instead.

Usage

Dict$remove(key)

Arguments

key

character name of key.

Returns

If key in Dict, remove it, otherwise raise an error.

---

Method replace()

Replace one element by another element. Search for occurence of old and, if found, replace it by new. If old does not exist, an error is signaled.

Usage

Dict$replace(old, new)

Arguments

old

element to be replaced

new

element to be put instead of old

Returns

the Dict object

---

Method set()

This function is deprecated. Use replace() instead.

Usage

Dict$set(key, value, add = FALSE)

Arguments

key

character name of key.

value

the value to be set

add

logical if TRUE the value is set regardless whether key already exists in Dict.

Returns

returns the Dict

---

Method sort()

Sort elements according to their keys. This function is deprecated as keys are now always sorted.

Usage

Dict$sort(decr = FALSE)

Arguments

decr

logical if TRUE sort in decreasing order.

Returns

returns the Dict

---

Method update()

Add elements of other to this if the name is not in the Dict and update elements with existing names.

Usage

Dict$update(other)

Arguments

other

Iterable object used to update this.

Returns

returns the updated Dict object.

---

Method values()

Get Container values

Usage

Dict$values()

Returns

a copy of all elements in a list

---

Method clone()

The objects of this class are cloneable with this method.

Usage

Dict$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

d = Dict$new(o = "one", na = NA, a = 1)
d
#> {a = 1, na = NA, o = "one"}
d$keys()
#> [1] "a"  "na" "o" 

d$add("li", list(1, 2))
#> {a = 1, li = list(1, 2), na = NA, o = "one"}
d$discard_at("na")
#> {a = 1, li = list(1, 2), o = "one"}
d$replace(1, 9)
#> {a = 9, li = list(1, 2), o = "one"}

d2 = Dict$new(a = 0, b = 1)
d$update(d2)
#> {a = 0, b = 1, li = list(1, 2), o = "one"}