Presentation Tags

Presentation tags are treated as whitespace to the code-generation part of the compiler. The parser notifies interested parties when a presentation tag is discovered, but the compiler ignores that notfication. These tags are used by editors to determine how to display the nearby source code.

Individual presentation tags fit between < and > delimiters, while a set of tags fits between ( and ) delimiters. There must be no whitespace between the opening ( for the set and the opening < for the first tag or between the closing > of the last tag and the closing ) of the set.. For example:

(<chunk state=expanded, handle=true><comment value=“Find the requested string.”>)
{
// A lot of detailed processing...
}
(</chunk>)

An editor vendor can make up additional tags for specific needs for that editor. The following table shows the standard presentation tags and how an editor should interpret them:

Tag	Modifier	Value	Meaning
chunk /chunk			These two comment tags delimit a “chunk” of source code that can be expanded or collapsed. Chunks usually correspond to blocks of source code that accomplish a specific part of a larger task. Collapsing these chunks can give the programmer a better high-level view of the general process involved in that larger task. If a comment tag appears in the same set of tags as this chunk tag, its comment will be displayed only when the chunk is collapsed. Chunks can be nested.
	handle	true \| false	A “handle” is a widget that allows the user to expand or collapse the chunk with a single click. This modifier determines whether such a handle is available. The editor should also provide some other means to expand or collapse chunks.
	state	expanded \| collapsed	How to display the chunk
comment			Linked or embedded source code comment
	embed		How to display comment in source code.
		none	Do not display comment
		value	Show the text specified by the value modifier or the raw contents of the file linked by the URL modifier.
		icon	Show an icon representing the comment. The editor should allow the user to choose operations (open, edit, etc.) for the comment’s object when the icon is selected in the source code.
		object	Embed an editor/player for the comment based on its MIME type
	mime	MIME type	The mime type of the file linked by the URL modifier.
	URL	any URL	The location of the object to be embedded
	value	any text	The text of the comment
tabdef /tabdef			Delimit the definition of a set of tab stops. This allows source code to be formatted consistently for different users without relying on how many space characters each user defines for a tab character.
	base	“name"	The name of another tabdef set on which to base this set. The named tabdef is copied onto this one before any other changes are made with additional tags or modifiers.
	default	ni \|nm \|nc	Sets the default interval between tab stops for this set. n is a numeric value that tells how far apart the default tab stops are. Use i to measure in inches, m for millimeters, and c for characters.
	name	“name"	Names the tabdef for use later in the source code.
tabadd			Add a tabstop to the tabdef currently being defined.
	align	left \| right \| center \| ‘char’	How to align text at this tab stop. Use ‘char’ to align to a specific character (decimal point, for example).
	position		Where the tabstop should go
		here	Put the tabstop wherever this tag ends up in the source file. This is helpful for lining up long parameter lists in a function call or complex nested expressions that span two or more lines.
		ni \|nm \|nc	Place the tabstop at the specified distance from the left margin.
tabrem	position	ni \|nm \|nc	Remove tabstop from the specified position of the tabdef currently being defined.
tabuse \tabuse	name	“name"	Delimits source code that is formatted by the tabdef specified by name.

Value

MIME type

any URL

any text