Files
old-gem/lib/lexer.rb
2020-02-05 13:40:37 +01:00

108 lines
2.5 KiB
Ruby

#--
# DO NOT MODIFY!!!!
# This file is automatically generated by rex 1.0.7
# from lexical definition file "./lib/specification.rex".
#++
require 'racc/parser'
class Query < Racc::Parser
require 'strscan'
class ScanError < StandardError ; end
attr_reader :lineno
attr_reader :filename
attr_accessor :state
def scan_setup(str)
@ss = StringScanner.new(str)
@lineno = 1
@state = nil
end
def action
yield
end
def scan_str(str)
scan_setup(str)
do_parse
end
alias :scan :scan_str
def load_file( filename )
@filename = filename
File.open(filename, "r") do |f|
scan_setup(f.read)
end
end
def scan_file( filename )
load_file(filename)
do_parse
end
def next_token
return if @ss.eos?
# skips empty actions
until token = _next_token or @ss.eos?; end
token
end
def _next_token
text = @ss.peek(1)
@lineno += 1 if text == "\n"
token = case @state
when nil
case
when (text = @ss.scan(/ +/))
;
when (text = @ss.scan(/\(/))
action { return [:L_BRACKET, text] }
when (text = @ss.scan(/\)/))
action { return [:R_BRACKET, text] }
when (text = @ss.scan(/(?i)or/))
action { return [:OPERATOR_OR, text] }
when (text = @ss.scan(/(?i)and/))
action { return [:OPERATOR_AND, text] }
when (text = @ss.scan(/(?i)not/))
action { return [:OPERATOR_NOT, text] }
when (text = @ss.scan(/"([^"]*)"/))
action { return [:TERM_WITH_QUOTES, text] }
when (text = @ss.scan(/[a-zA-Z0-9\-_]+/))
action { return [:TERM_WITHOUT_QUOTES, text] }
when (text = @ss.scan(/\:/))
action { return [:COLON, text] }
else
text = @ss.string[@ss.pos .. -1]
raise ScanError, "can not match: '" + text + "'"
end # if
else
raise ScanError, "undefined state: '" + state.to_s + "'"
end # case state
token
end # def _next_token
def tokenize(code)
scan_setup(code)
tokens = []
while token = next_token
tokens << token
end
tokens
end
end # class