BSON::Ordered

A role implementing Associativity.

Description

This role mimics the Hash behavior with a few differences because of the BSON specs. This role is used by the BSON::Document where you can find other information.

Synopsis

Declaration

unit class BSON::Ordered:auth<github:MARTIMM>;
also does Associative;

Methods

AT-KEY

Look up a key and return its value. Please note that the key is automatically created when the key does not exist. In that case, an empty BSON::Document value is returned. This is necessary when an assignment to deep level keys are done. If you don’t want this to happen, you may check the existence of a key first and decide on that outcome. See :exists below.

Example

# look up a value
say $document<some-key>;

# assign a value. $document<a><b> is looked up and the last one is
# taken care of by ASSIGN-KEY().
$document<a><b><c> = 'abc';

ASSIGN-KEY

Define a key and assign a value to it.

Example

$document<x> = 'y';

BIND-KEY

Binding a value to a key.

Example

my $y = 12345;
$document<y> := $y;
note $document<y>;   # 12345
$y = 54321;
note $document<y>;   # 54321

EXISTS-KEY

Check existence of a key

Example

$document<Foo> = 'Bar' if $document<Foo>:!exists;

Do not check for undefinedness like below. In that case, when key did not exist, the key is created and set with an empty BSON::Document. //= will then see that the value is defined and the assignment is not done;

# this results in assignment of an empty BSON::Document
$document<Foo> //= 'Bar';

DELETE-KEY

Delete a key with its value. The value is returned.

Example

my $old-foo-key-value = $document<Foo>:delete

elems

Return the number of keys and values in the document

Example

say 'there are elements in the document' if $document.elems;

kv

Return a sequence of key and value

Example

for $document.kv -> $k, $v {
  …
}

pairs

Get a sequence of pairs

Example

for $document.pairs -> Pair $p {
  …
}

keys

Get a sequence of keys from the document.

Example

for $document.keys -> Str $k {
  …
}

values

Example

for $document.values -> $v {
  …
}

raku, perl

Show the structure of a document

method raku ( Int :$indent --> Str ) is also<perl>

• Int $indent; setting the starting indentation.