# frozen_string_literal: true
##
# Collection of methods for writing parsers
module RDoc::Parser::RubyTools
##
# Adds a token listener +obj+, but you should probably use token_listener
def add_token_listener(obj)
@token_listeners ||= []
@token_listeners << obj
end
##
# Fetches the next token from the scanner
def get_tk
tk = nil
if @tokens.empty? then
if @scanner_point >= @scanner.size
return nil
else
tk = @scanner[@scanner_point]
@scanner_point += 1
@read.push tk[:text]
end
else
@read.push @unget_read.shift
tk = @tokens.shift
end
if tk == nil || :on___end__ == tk[:kind]
tk = nil
end
return nil unless tk
# inform any listeners of our shiny new token
@token_listeners.each do |obj|
obj.add_token(tk)
end if @token_listeners
tk
end
##
# Reads and returns all tokens up to one of +tokens+. Leaves the matched
# token in the token list.
def get_tk_until(*tokens)
read = []
loop do
tk = get_tk
case tk
when *tokens then
unget_tk tk
break
end
read << tk
end
read
end
##
# Retrieves a String representation of the read tokens
def get_tkread
read = @read.join("")
@read = []
read
end
##
# Peek equivalent for get_tkread
def peek_read
@read.join('')
end
##
# Peek at the next token, but don't remove it from the stream
def peek_tk
unget_tk(tk = get_tk)
tk
end
##
# Removes the token listener +obj+
def remove_token_listener(obj)
@token_listeners.delete(obj)
end
##
# Resets the tools
def reset
@read = []
@tokens = []
@unget_read = []
@nest = 0
@scanner_point = 0
end
##
# Skips whitespace tokens including newlines
def skip_tkspace
tokens = []
while (tk = get_tk) and (:on_sp == tk[:kind] or :on_nl == tk[:kind] or :on_ignored_nl == tk[:kind]) do
tokens.push(tk)
end
unget_tk(tk)
tokens
end
##
# Skips whitespace tokens excluding newlines
def skip_tkspace_without_nl
tokens = []
while (tk = get_tk) and :on_sp == tk[:kind] do
tokens.push(tk)
end
unget_tk(tk)
tokens
end
##
# Has +obj+ listen to tokens
def token_listener(obj)
add_token_listener obj
yield
ensure
remove_token_listener obj
end
##
# Returns +tk+ to the scanner
def unget_tk(tk)
@tokens.unshift tk
@unget_read.unshift @read.pop
# Remove this token from any listeners
@token_listeners.each do |obj|
obj.pop_token
end if @token_listeners
nil
end
end
|