page

Class: Rep

page.EBNF. Rep

Represents an iteration for EBNF.

<private> new Rep(_node, _min, _max)

Creates a new representation of an iteration for EBNF.

Parameters:
Name Type Description
_node eNode

body; null if called during unmarshalling.
_min number

minimum number of occurences, 0 or 1.
_max number

maximum number of occurences, 1 or undefined.
Properties:
Name Type Description
node eNode

body.
min number

minimum number of occurences, 0 or 1.
max number

maximum number of occurences, 1 or undefined.
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:
Example
some: item +;
many: item *;
optional: item ?;

Methods

<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.Rep.nt and then delegates to the descendant.

Source:

<private> toBNF(_grammar [, _nt])

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

a+
a*
a?

where .min and .max are 1:undefined, 0:undefined, or 0:1, respectively, are translated to

$#: a $##;   # .min == 1
$##: ;
$##: a $##;

$#: $##;     # if left-hand side is known
$##: ;       # .min == 0
$##: a $##;

$#: ;        # .min == 0, .max == 1
$#: a;
Parameters:
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:
Returns:

non-terminal representing the translated construct.

Type
page.BNF.NT

toString()

Displays iteration in EBNF notation.

Source:
Returns:
Type
string