page Class: Alt

Creates a new representation of a choice for EBNF.

Name	Type	Description
`_nodes`	Array.<eNode>	alternatives, at least two.

Name	Type	Description
`nodes`	Array.<eNode>	descendants, at least two.
`nt`	page.BNF.NT	corresponding non-terminal for BNF.
`empty`	boolean	true if no input can be accepted.
`first`	Map	terminals at front, maps ord to page.BNF.T.
`follow`	Map	terminals following, maps ord to page.BNF.T.

Source:

choice: a | b;

<private> init()

Called once by page.EBNF#init to complete EBNF grammar initialization. Imports page.BNF.NT.empty, page.BNF.NT.first, and page.BNF.NT.follow from page.EBNF.Alt.nt and then delegates to the descendants.

Source:

<private> toBNF(_grammar [, _nt])

Called once by page.EBNF#init to recursively translate into BNF.

a | b | c

is translated to

$#: a;
$#: b;
$#: c;

Name	Type	Argument	Description
`_grammar`	page.EBNF		object to which the construct belongs.
`_nt`	page.EBNF.NT	<optional>	left-hand side, if known; avoids the need for a fresh non-terminal.

Source:

non-terminal representing the translated construct.

toString()

Displays alternatives in EBNF notation.

Source:

Class: Alt