Class: EBNF::ABNF

Inherits:

Object

Object
EBNF::ABNF

Includes:: PEG::Parser

Defined in:: lib/ebnf/abnf.rb

Constant Summary collapse

ALPHA = Regular expressions for both “Core” and ABNF-specific terminals.

%r{[\x41-\x5A\x61-\x7A]}

VCHAR =

%r{[\x20-\x7E]}

WSP =

%r{[\x20\x09]}

CRLF =

%r{\x0D?\x0A}

COMMENT =

%r{;(?:#{WSP}|#{VCHAR})*#{CRLF}}

C_NL =

%r{#{COMMENT}|#{CRLF}}

C_WSP =

%r{#{WSP}|(?:#{C_NL}#{WSP})}

Instance Attribute Summary collapse

#parsed_rules ⇒ Hash{Symbol => EBNF::Rule} readonly

Hash of generated Rule objects by symbol.

Attributes included from PEG::Parser

#packrat, #scanner, #whitespace

Instance Method Summary collapse

#ast ⇒ Array<EBNF::Rule>

The AST includes the parsed rules along with built-in rules for ABNF used within the parsed grammar.
#initialize(input, **options) ⇒ EBNFParser constructor

## Parser invocation.

Methods included from PEG::Parser

#clear_packrat, #debug, #depth, #error, #find_rule, included, #onFinish, #onStart, #onTerminal, #parse, #prod_data, #progress, #terminal_options, #terminal_regexp, #update_furthest_failure, #warn

Constructor Details

#initialize(input, **options) ⇒ `EBNFParser`

## Parser invocation. On start, yield ourselves if a block is given, otherwise, return this parser instance

Parameters:

input (#read, #to_s)
options (Hash{Symbol => Object})

Options Hash (**options):

:level (Boolean) —

Trace level. 0(debug), 1(info), 2(warn), 3(error).

# File 'lib/ebnf/abnf.rb', line 235

def initialize(input, **options)
  # If the `level` option is set, instantiate a logger for collecting trace information.
  if options.has_key?(:level)
    options[:logger] = Logger.new(STDERR)
    options[:logger].level = options[:level]
    options[:logger].formatter = lambda {|severity, datetime, progname, msg| "#{severity} #{msg}\n"}
  end

  # Read input, if necessary, which will be used in a Scanner.
  @input = input.respond_to?(:read) ? input.read : input.to_s

  @parsed_rules = {}

  # Parses into `@parsed_rules`
  parse(@input,
        :rulelist,        # Starting rule
        ABNFMeta::RULES,  # PEG rules
        whitespace: '',   # No implicit whitespace
        **options)
rescue EBNF::PEG::Parser::Error => e
  raise SyntaxError, e.message
end

Instance Attribute Details

#parsed_rules ⇒ `Hash{Symbol => EBNF::Rule}` (readonly)

Hash of generated Rule objects by symbol

Returns:

(Hash{Symbol => EBNF::Rule})



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# File 'lib/ebnf/abnf.rb', line 24

def parsed_rules
  @parsed_rules
end

Instance Method Details

#ast ⇒ `Array<EBNF::Rule>`

The AST includes the parsed rules along with built-in rules for ABNF used within the parsed grammar.