Multiple changes:

- Move to a Python process for the LanguageLink client [fixes #1, presumably]
- Finish a first rough draft of the booklet [fixes #4]

carp/src/bridge/flask_platform.py

@@ -0,0 +1,73 @@
+from flask import Flask, request
+import http.client
+import json
+import threading
+import bridge.globals
+import bridge.utils
+from bridge import json_encoder
+import sys
+import logging
+import requests
+
+class FlaskMsgService:
+
+    def __init__(self, port, pharo_port, feed_callback):
+        self.serializer = json_encoder.JsonSerializer()
+        log = logging.getLogger('werkzeug')
+        log.setLevel(logging.ERROR)
+        self.thread = None
+        self.port = port
+        self.pharo_port = pharo_port
+        self.feed_callback = feed_callback
+        self.app = Flask('carp_bridge')
+        self.app.use_reloader=False
+        self.session = requests.Session()
+        self.session.trust_env = True
+
+        @self.app.route("/ENQUEUE", methods=["POST"])
+        def eval_expression():
+            data = request.get_json(force=True)
+            self.feed_callback(data)
+            return "{}"
+
+        @self.app.route("/IS_ALIVE", methods=["POST"])
+        def status_endpoint():
+            return "{}"
+        
+    def addMapping(self, key_type, mapping_function):
+        json_encoder.addMapping(key_type, mapping_function)
+
+    def _start(self):
+        try:
+            self.app.run(port=self.port)
+        except OSError as err:
+            bridge.globals.logger.log('Critical Error:' + str(err))
+            exit(42)
+    
+    def start(self):
+        self.thread = threading.Thread(target=self._start, args=())
+        self.thread.daemon = True
+        self.thread.start()
+
+    def is_running(self):
+        return self.thread != None
+
+    def stop(self):
+        pass
+
+    def send_async_message(self, msg):
+        self.send_sync_message(msg)
+    
+    def send_sync_message(self, msg):
+        msg['__sync'] = bridge.utils.random_str()
+        bridge.globals.logger.log("SYNC_MSG: " + json.dumps(msg))
+        response = self.session.post(
+            'http://localhost:' + str(self.pharo_port) + '/' + msg['type'], 
+            data=json.dumps(msg),
+            headers={'content-type': 'application/json'}, 
+            allow_redirects=True).content.decode('utf-8')
+        bridge.globals.logger.log("SYNC_ANS: " + response)
+        return json.loads(response)
+
+def build_service(port, pharo_port, feed_callback):
+    return FlaskMsgService(port, pharo_port, feed_callback)