:let xs = count(list, 'x')	" count nr of times 'x' appears in list
	:let i = index(list, 'x')	" index of first 'x' in list
	:let lines = getline(1, 10)	" get ten text lines from buffer
	:call append('$', lines)	" append text lines in buffer
	:let list = split("a b c")	" create list from items in a string
	:let string = join(list, ', ')	" create string from list items
	:let s = string(list)		" String representation of list
	:call map(list, '">> " .. v:val')  " prepend ">> " to each item

Don't forget that a combination of features can make things simple.  For
example, to add up all the numbers in a list: >
	:exe 'let sum = ' .. join(nrlist, '+')


1.4 Dictionaries ~
				 *Dict* *dict* *Dictionaries* *Dictionary*
A Dictionary is an associative array: Each entry has a key and a value.  The
entry can be located with the key.  The entries are stored without a specific
ordering.


Dictionary creation ~
						*E720* *E721* *E722* *E723*
A Dictionary is created with a comma-separated list of entries in curly
braces.  Each entry has a key and a value, separated by a colon.  Each key can
only appear once.  Examples: >
	:let mydict = {1: 'one', 2: 'two', 3: 'three'}
	:let emptydict = {}
<							*E713* *E716* *E717*
A key is always a String.  You can use a Number, it will be converted to a
String automatically.  Thus the String '4' and the number 4 will find the same
entry.  Note that the String '04' and the Number 04 are different, since the
Number will be converted to the String '4', leading zeros are dropped.  The
empty string can also be used as a key.
						*literal-Dict* *#{}*
To avoid having to put quotes around every key the #{} form can be used.  This
does require the key to consist only of ASCII letters, digits, '-' and '_'.
Example: >
	:let mydict = #{zero: 0, one_key: 1, two-key: 2, 333: 3}
Note that 333 here is the string "333".  Empty keys are not possible with #{}.

A value can be any expression.  Using a Dictionary for a value creates a
nested Dictionary: >
	:let nestdict = {1: {11: 'a', 12: 'b'}, 2: {21: 'c'}}

An extra comma after the last entry is ignored.


Accessing entries ~

The normal way to access an entry is by putting the key in square brackets: >
	:let val = mydict["one"]
	:let mydict["four"] = 4

You can add new entries to an existing Dictionary this way, unlike Lists.

For keys that consist entirely of letters, digits and underscore the following
form can be used |expr-entry|: >
	:let val = mydict.one
	:let mydict.four = 4

Since an entry can be any type, also a List and a Dictionary, the indexing and
key lookup can be repeated: >
	:echo dict.key[idx].key


Dictionary to List conversion ~

You may want to loop over the entries in a dictionary.  For this you need to
turn the Dictionary into a List and pass it to |:for|.

Most often you want to loop over the keys, using the |keys()| function: >
	:for key in keys(mydict)
	:   echo key .. ': ' .. mydict[key]
	:endfor

The List of keys is unsorted.  You may want to sort them first: >
	:for key in sort(keys(mydict))

To loop over the values use the |values()| function:  >
	:for v in values(mydict)
	:   echo "value: " .. v
	:endfor

If you want both the key and the value use the |items()| function.  It returns
a List in which each item is a List with two items, the key and the value: >
	:for [key, value] in items(mydict)
	:   echo key .. ': ' .. value
	:endfor


Dictionary identity ~
							*dict-identity*
Just like Lists you need to use |copy()| and |deepcopy()| to make a copy of a
Dictionary.  Otherwise, assignment results in referring to the same
Dictionary: >
	:let onedict = {'a': 1, 'b': 2}
	:let adict = onedict
	:let adict['a'] = 11
	:echo onedict['a']
	11

Two Dictionaries compare equal if all the key-value pairs compare equal.  For
more info see |list-identity|.


Dictionary modification ~
							*dict-modification*
To change an already existing entry of a Dictionary, or to add a new entry,
use |:let| this way: >
	:let dict[4] = "four"
	:let dict['one'] = item