Required item. Required items appear on
the main path of the horizontal line. You must specify these items.
|
>>-KEYWORD--required_item--------------------------------------><
|
Required choice. A required choice (two
or more items) appears in a vertical stack on the main path of the
horizontal line. You must choose one of the items in the stack.
|
>>-KEYWORD--+-required_choice1-+-------------------------------><
'-required_choice2-'
|
Optional item. Optional items appear below
the main path of the horizontal line.
|
>>-KEYWORD--+---------------+----------------------------------><
'-optional_item-'
|
Optional choice. An optional choice (two
or more items) appears in a vertical stack below the main path of
the horizontal line. You may choose one of the items in the stack.
|
>>-KEYWORD--+------------------+-------------------------------><
+-optional_choice1-+
'-optional_choice2-'
|
Default. Default items appear above the
main path of the horizontal line. The remaining items (required or
optional) appear on (required) or below (optional) the main path of
the horizontal line. The following example displays a default with
optional items.
|
.-default_choice1--.
>>-KEYWORD--+------------------+-------------------------------><
+-optional_choice2-+
'-optional_choice3-'
|
Variable. Variables appear in lowercase
italics. They represent names or values.
|
>>-KEYWORD--variable-------------------------------------------><
|
Repeatable item. An arrow returning to
the left above the main path of the horizontal line indicates an
item that can be repeated.
A character within the arrow means
you must separate repeated items with that character.
An
arrow returning to the left above a group of repeatable items indicates
that one of the items can be selected,or a single item can be repeated.
|
.-----------------.
V |
>>-KEYWORD----repeatable_item-+--------------------------------><
.-,---------------.
V |
>>-KEYWORD----repeatable_item-+--------------------------------><
|
Fragment. The fragment symbol indicates
that a labelled group is described below the main syntax diagram.
Syntax is occasionally broken into fragments if the inclusion of
the fragment would overly complicate the main syntax diagram.
|
>>-KEYWORD--| fragment |---------------------------------------><
fragment
|--+-,required_choice1----------------------+-------------------|
| .-,default_choice--. |
'-,required_choice2-+------------------+-'
'-,optional_choice-'
|