page

Class: Lst

page.EBNF. Lst

Represents a delimited iteration for EBNF.

<private> new Lst(_node, _delim, _min)

Creates a new representation of a delimited iteration for EBNF.

Parameters:
Name Type Description
_node eNode

body; null if called during unmarshalling.
_delim eNode

delimiter; null if called during unmarshalling.
_min number

minimum number of occurences, 0 or 1.
Properties:
Name Type Description
node eNode

body.
delim eNode

delimiter.
min number

minimum number of occurences, 0 or 1.
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 +/ delimiter;
many: item ⭑/ delimiter;

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.Lst#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
a ⭑/ b

where .min is 1 or 0, respectively, are translated to

$#:  ;         # for min == 0
$#:  a $##;    # factored out
$##: ;
$##: b 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 delimited iteration in EBNF notation.

Source:
Returns:
Type
string