lib/nlp: add wrapper to the web REST api

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/lib/nlp/examples/nlp_server.nit b/lib/nlp/examples/nlp_server.nit
new file mode 100644 (file)
index 0000000..61dd888
--- /dev/null
+++ b/lib/nlp/examples/nlp_server.nit
@@ -0,0 +1,37 @@
+# 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 nlp_server
+
+import nlp
+import config
+
+redef class Config
+
+       var opt_java_cp = new OptionString("StanfordNLP java classpath", "-c", "--classpath")
+       var opt_port = new OptionInt("Server port on localhost (default is 9000)", 9000, "-p", "--port")
+
+       redef init do
+               opts.add_option(opt_java_cp, opt_port)
+       end
+end
+
+var config = new Config
+config.parse_options(args)
+
+var cp = config.opt_java_cp.value
+if cp == null then cp = "stanfordnlp/*"
+
+var srv = new NLPServer(cp, config.opt_port.value)
+srv.start

diff --git a/lib/nlp/stanford.nit b/lib/nlp/stanford.nit
index 29058b3..22153b5 100644 (file)
--- a/lib/nlp/stanford.nit
+++ b/lib/nlp/stanford.nit
@@ -19,6 +19,8 @@ module stanford
 
 import opts
 import dom
+import curl
+import pthreads
 
 # Natural Language Processor
 #
@@ -285,3 +287,81 @@ class NLPToken
                init(index, word, lemma, begin_offset, end_offset, pos)
        end
 end
+
+# Stanford web server
+#
+# Runs the server on `port`.
+#
+# For more details about the stanford NLP server see
+# https://stanfordnlp.github.io/CoreNLP/corenlp-server.html
+class NLPServer
+       super Thread
+
+       # Stanford jar classpath
+       #
+       # Classpath to give to Java when loading the StanfordNLP jars.
+       var java_cp: String
+
+       # Port the Java server will listen on
+       var port: Int
+
+       redef fun main do
+               sys.system "java -mx4g -cp \"{java_cp}\" edu.stanford.nlp.pipeline.StanfordCoreNLPServer -port {port.to_s} -timeout 15000"
+               return null
+       end
+end
+
+# A NLPProcessor using a NLPServer as backend
+class NLPClient
+       super NLPProcessor
+
+       # Base uri of the NLP server API
+       #
+       # For examples "http://localhost:9000" or "https://myserver.com"
+       var api_uri: String
+
+       # Annotators to use
+       #
+       # The specified annotators must exist on the server.
+       #
+       # Defaults are: `tokenize`, `ssplit`, `pos` and `lemma`.
+       var annotators: Array[String] = ["tokenize", "ssplit", "pos", "lemma"] is writable
+
+       # Language to process
+       #
+       # The language must be available on the server.
+       #
+       # Default is `en`.
+       var language = "en" is writable
+
+       # Output format to ask.
+       #
+       # Only `xml` is implemented at the moment.
+       private var format = "xml"
+
+       # API uri used to build curl POST requests
+       fun post_uri: String do
+               return "{api_uri}/?properties=%7B%22annotators%22%3A%20%22tokenize%2Cssplit%2Cpos%2clemma%22%2C%22outputFormat%22%3A%22{format}%22%7D&pipelineLanguage={language}"
+       end
+
+       redef fun process(string) do
+               var request = new CurlHTTPRequest(post_uri)
+               request.body = string
+               var response = request.execute
+               if response isa CurlResponseSuccess then
+                       if response.status_code != 200 then
+                               print "Error: {response.body_str}"
+                               return new NLPDocument
+                       end
+                       var xml = response.body_str.to_xml
+                       if xml isa XMLError then
+                               print xml
+                       end
+                       return new NLPDocument.from_xml(response.body_str.to_xml.as(XMLDocument))
+               else if response isa CurlResponseFailed then
+                       print "Error: {response.error_msg}"
+                       return new NLPDocument
+               end
+               return new NLPDocument
+       end
+end