class DBus::Type::Parser

D-Bus type parser class¶ ↑

Helper class to parse a type signature in the protocol. @api private

Public Class Methods

new(signature) click to toggle source

Create a new parser for the given signature. @param signature [Signature]

    # File lib/dbus/type.rb
197 def initialize(signature)
198   @signature = signature
199   if signature.size > 255
200     msg = "Potential signature is longer than 255 characters (#{@signature.size}): #{@signature}"
201     raise SignatureException, msg
202   end
203 
204   @idx = 0
205 end

Public Instance Methods

nextchar() click to toggle source

Returns the next character from the signature.

    # File lib/dbus/type.rb
208 def nextchar
209   c = @signature[@idx]
210   @idx += 1
211   c
212 end

parse() click to toggle source

Parse the entire signature, return a DBus::Type object. @return [Array<Type>]

    # File lib/dbus/type.rb
263 def parse
264   @idx = 0
265   ret = []
266   while (c = nextchar)
267     ret << parse_one(c)
268   end
269   ret.freeze
270 end

parse1() click to toggle source

Parse one {SingleCompleteType} @return [Type]

    # File lib/dbus/type.rb
274 def parse1
275   c = nextchar
276   raise SignatureException, "Empty signature, expecting a Single Complete Type" if c.nil?
277 
278   t = parse_one(c)
279   raise SignatureException, "Has more than a Single Complete Type: #{@signature}" unless nextchar.nil?
280 
281   t.freeze
282 end

parse_one(char, for_array: false) click to toggle source

Parse one character char of the signature. @param for_array [Boolean] are we parsing an immediate child of an ARRAY @return [Type]

    # File lib/dbus/type.rb
217 def parse_one(char, for_array: false)
218   res = nil
219   case char
220   when "a"
221     res = Type.new(ARRAY)
222     char = nextchar
223     raise SignatureException, "Empty ARRAY in #{@signature}" if char.nil?
224 
225     child = parse_one(char, for_array: true)
226     res << child
227   when "("
228     res = Type.new(STRUCT, abstract: true)
229     while (char = nextchar) && char != ")"
230       res << parse_one(char)
231     end
232     raise SignatureException, "STRUCT not closed in #{@signature}" if char.nil?
233     raise SignatureException, "Empty STRUCT in #{@signature}" if res.members.empty?
234   when "{"
235     raise SignatureException, "DICT_ENTRY not an immediate child of an ARRAY" unless for_array
236 
237     res = Type.new(DICT_ENTRY, abstract: true)
238 
239     # key type, value type
240     2.times do |i|
241       char = nextchar
242       raise SignatureException, "DICT_ENTRY not closed in #{@signature}" if char.nil?
243 
244       raise SignatureException, "DICT_ENTRY must have 2 subtypes, found #{i} in #{@signature}" if char == "}"
245 
246       res << parse_one(char)
247     end
248 
249     # closing "}"
250     char = nextchar
251     raise SignatureException, "DICT_ENTRY not closed in #{@signature}" if char.nil?
252 
253     raise SignatureException, "DICT_ENTRY must have 2 subtypes, found 3 or more in #{@signature}" if char != "}"
254   else
255     res = Type.new(char)
256   end
257   res.members.freeze
258   res
259 end