1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
#!/usr/bin/python3
import collections
import http.client
import json
import re
import urllib
# Create a new pengine, initialize it with [code] and return its ID. The engine
# will be destroyed after completing one query.
def create(code=''):
opts = {'format': 'json-s', 'destroy': True, 'src_text': code}
reply, messages = request('POST', '/pengine/create', body=json.dumps(opts))
if reply.get('event') != 'create' or 'error' in messages:
raise Exception('\n'.join(messages['error']))
return reply['id']
# Create a new pengine with [code], run [query] and destroy the engine. Return
# the reply from engine.
def create_and_ask(code, query):
opts = {'format': 'json-s', 'destroy': True, 'src_text': code, 'ask': query}
reply, messages = request('POST', '/pengine/create', body=json.dumps(opts))
if reply.get('event') != 'create' or 'error' in messages:
raise Exception('\n'.join(messages['error']))
return reply['answer']['data']
def ask(engine, query):
return send(engine, 'ask(({}),[])'.format(query))
def next(engine, n=1):
return send(engine, 'next({})'.format(n))
def stop(engine):
return send(engine, 'stop')
def destroy(engine):
return send(engine, 'destroy')
def send(engine, event):
params = urllib.parse.urlencode({
'id': engine,
'event': event,
'format': 'json-s'})
reply, messages = request('GET', '/pengine/send?' + params)
return reply
# Return the main reply and pull potential output replies.
address, port = 'localhost', 3030 # TODO put this somewhere sane
def request(method, path, body=None):
headers = {'Content-Type': 'application/json;charset=utf-8'}
messages = collections.defaultdict(list)
try:
conn = http.client.HTTPConnection(address, port, timeout=10)
conn.request(method, path, body, headers=headers)
while True:
response = conn.getresponse()
if response.status != http.client.OK:
raise Exception('server returned {}'.format(response.status))
reply = json.loads(response.read().decode('utf-8'))
if reply.get('event') == 'output':
msg_type, msg_data = get_message(reply)
messages[msg_type].append(msg_data)
# Request next reply.
params = urllib.parse.urlencode({
'id': reply['id'],
'format': 'json-s'})
conn.request('GET', '/pengine/pull_response?' + params, headers=headers)
else:
return reply, messages
finally:
conn.close()
# Strip boilerplate from Prolog messages … ugly.
def get_message(reply):
match = re.match(r'.*<pre class="[^"]*">(.*)</pre>.*',
reply['data'], flags=re.DOTALL)
data = match.group(1).strip()
message = ''
if reply['message'] == 'error':
if 'location' in reply:
loc = reply['location']
message += 'near line ' + str(loc['line'])
if 'ch' in loc:
message += ', character ' + str(loc['ch'])
message += ': '
if reply.get('code') == 'syntax_error':
match = re.match(r'^.*Syntax error: (.*)$', data, flags=re.DOTALL)
data = match.group(1)
elif reply.get('code') == 'permission_error':
match = re.match(r'^.*(No permission [^\n]*)', data, flags=re.DOTALL)
data = match.group(1)
elif reply.get('code') == 'type_error':
match = re.match(r'^.*(Type error: [^\n]*)', data, flags=re.DOTALL)
data = match.group(1)
message += data
# Replace anonymous variable names with _.
message = re.sub(r'_G[0-9]*', '_', message)
return reply['message'], message
# Basic sanity check.
if __name__ == '__main__':
engine = create(code='dup([],[]). dup([H|T],[H,H|TT]) :- dup(T,TT).')
print('engine id is ' + engine)
print(ask(engine, "run_tests({}, Result)".format('dup/2')))
destroy(engine)
|
