# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
module re_app
import re_parser
import popcorn
import popcorn::pop_config
class REHandler
super Handler
redef fun get(req, res) do
res.html new RETemplate
end
redef fun post(req, res) do
# TODO Retrieve re from post body
var re = req.string_arg("re")
var tpl = new RETemplate
if re == null or re.is_empty then
tpl.error = "Error: empty regexp"
res.html tpl
return
end
tpl.re = re
# Parse re
var re_parser = new REParser
var node = re_parser.parse_re(re)
if node == null then
tpl.error = re_parser.last_error.as(not null)
res.html tpl
return
end
# Build nfa and dfa
var nfa = re_parser.make_nfa(node)
tpl.nfa = automaton_to_svg(nfa)
tpl.dfa = automaton_to_svg(nfa.to_dfa)
res.html tpl
end
private fun automaton_to_svg(automaton: Automaton): String do
automaton.to_dot(false).write_to_file "dot.tmp"
sys.system "dot -Tsvg -osvg.tmp dot.tmp"
var svg = "svg.tmp".to_path.read_all
sys.system "rm -f dot.tmp svg.tmp"
return svg
end
end
class RETemplate
super Template
var re = "a*(b|cd?)+"
var nfa: nullable String = null
var dfa: nullable String = null
var error: nullable String = null
redef fun rendering do
add """
REParser
Regular Expressions to NFA and DFA
"""
var error = self.error
if error != null then
add """
{{{error}}}
"""
end
var nfa = self.nfa
if nfa != null then
add """
NFA
{{{nfa}}}
"""
end
var dfa = self.dfa
if dfa != null then
add """
"""
end
end
var config = new AppConfig
config.parse_options(args)
var app = new App
app.use("/", new REHandler)
app.listen(config.app_host, config.app_port)