Single-Line Value Lists

Single-line values can always be combined into a list using a comma (,) as a separator.

sl_value_or_list    ::= sl_value (sl_list_separator sl_value)+
sl_list_separator   ::= spacing COMMA spacing

value
value , value
value , value , value , value , ...

• In the EBNF syntax above, the symbol sl_value is described in Named Values.

• The symbol spacing is described in Spacing.

Single-Line Value List Rules

1. Commas Form a List: Values separated by commas (,) form a value list.

   [main]
   value list: 1, 2, 3, 4, 5
   

2. Spacing Around Separator: Optional spacing is allowed before and after the comma.

   [main]
   value list 1:   7 ,   1 ,   9
   value list 2: 105 , 722 , 817
   

3. No Prefixing/Trailing Comma: A value list must not start or end with a comma.

   [main]
   value list 1: ,1 , 2      # ERROR! Value list must not start with comma
   value list 2: 1, 2,       # ERROR! Value list must not end with comma.
   

4. No Consecutive Commas: Consecutive commas, with no value between them, are not allowed.

   [main]
   value list: 1, , 2        # ERROR! Consecutive commas are not allowed.
   

5. No Multi-line Values: Multi-line values are not allowed in single-line value lists.

   [main]
   value list: """
       text
       """, """        # ERROR! Multi-line values are not allowed in lists.
       text
       """
   

Example

[main]
first list: 1, 2, 3, 4     # Value lists are created by separating values with commas.
second list: 1  , 2  ,  3  # Spacing is allowed around the comma.

Features

Feature	Coverage
value-list	The syntax outlined in this chapter is part of the standard feature value lists.

Errors

Error Code	Causes
Syntax	Raised if a single line value list contains a multi-line value, such as multi-line text. Raised if a value list contains prefixed, trailing, or consecutive commas.