Markup spec/BNF/Special block
EBNF grammar project
Special blocks are things like itemized lists starting with *
; they can only be specified at the start of a line and usually run till the end of the line.
<special-block> ::= <horizontal-rule> | <heading> | <list-item> | <table> | <space-block> | ...
The dots need to be filled in.
Horizontal rule
[edit]A horizontal rule is specified by 4 or more dashes. It is translated to an <hr> element.
<horizontal-rule> ::= "----" [<dashes>] [<inline-text>] <newline>
<dashes> ::= "-" [<dashes>]
If the inline-text
is present, it is not wrapped in a <p> element.
Heading
[edit]A level-n heading is translated to an <hn> element.
<heading> ::= <level-6-heading> | <level-5-heading> | <level-4-heading>
| <level-3-heading> | <level-2-heading> | <level-1-heading>
<level-6-heading> ::= "======" <inline-text> "======" <space-tabs> <newline>
<level-5-heading> ::= "=====" <inline-text> "=====" <space-tabs> <newline>
<level-4-heading> ::= "====" <inline-text> "====" <space-tabs> <newline>
<level-3-heading> ::= "===" <inline-text> "===" <space-tabs> <newline>
<level-2-heading> ::= "==" <inline-text> "==" <space-tabs> <newline>
<level-1-heading> ::= "=" <inline-text> "=" <space-tabs> <newline>
The alternatives in the first rule need to be tried from left to right.
Some notes (as implied by the grammar):
- An unterminated heading tag is treated as normal text.
- Unbalanced tags are treated as the shorter of the two tags (i.e. ==== heading == renders as the level 2 heading == heading)
- More than 6 = signs are treated as 6, with the extra symbols being included in the header.
List item
[edit]<list-item> ::= <indent-item> | <enumerated-item> | <bullet-item>
<indent-item> ::= ":" [(<list-item> | <item-body>)]
<enumerated-item> ::= "#" [(<list-item> | <item-body>)]
<bullet-item> ::= "*" [(<list-item> | <item-body>)]
<item-body> ::= <defined-term> | [<whitespace>] <inline-text>
<defined-term> ::= ";" <text> [ (<definition>)]
<definition> ::= ":" <inline-text>
Semantics:
<indent-item>
and<definition>
are translated to a <dd> element, wrapped in a <dl>- A
<bullet-item>
is translated to a <li> element wrapped in a <ul>. - An
<enumerated-item>
is translated to a <li> element wrapped in a <ol>. - A
<defined-term>
is translated to a <dt> element wrapped in a <dl>.
Notes:
- The grouping of successive list items cannot be captured in EBNF. The simplest approach would appear to be a second pass whereby successive pairings of close/open list are eliminated. For example, <ol><li>Foo</li>
</ol><ol><li>Boo</li></ol> would be rewritten as <ol><li>Foo</li><li>Boo</li></ol> <list-item>
and<defined-term>
are obviously matched in preference to<inline-text>
. The user has to insert whitespace in order to get inline-text starting with #, ;, * or :.- The current parser accepts a wide range of syntax than the above, allowing other list items to appear after a definition list (;). This appears to be arbitrary, unpredictable and not particularly useful. See bug11894.
Table
[edit]From meta...minor reformatting
<Table> ::= "{|" [ " " TableParameters ] NewLine TableFirstRow "|}" ;
<TableFirstRow> ::= TableColumnLine NewLine | TableColumnMultiLine | TableRow ;
<TableRow> ::= "|-" [ CSS ] NewLine TableColumn [ TableRow ] ;
<TableColumn> ::= TableColumnLine | TableColumnMultiLine ;
<TableColumnLine> ::= "|" InlineText [ "|" TableColumnLine ] ;
<TableColumnMultiLine> ::= "|" [ TableCellParameters "|" ] AnyText NewLine [ TableColumnMultiLine ] ;
<TableParameters> ::= CSS | ? HTML table attributes ? ;
<TableCellParameter> ::= CSS | ? HTML cell attributes ? ;
Space block
[edit]Starting a line with a space creates a pre-formatted block of text similar to using <pre>. The big difference is that the contained text is still parsed and rendered normally.
<space-block> ::= " " <inline-text> <newline> [ {<space-block-2} ]
<space-block-2> ::= " " [<inline-text>] <newline>
- Rendering
- The block is surrounded with <pre>. White space and newlines are preserved literally.
- Note that the first line of a space block must have text in it. Subsequent lines can be composed of just spaces.