Initial stab at asyncio integration

1 files changed, 72 insertions, 0 deletions

diff --git a/pexpect/async.py b/pexpect/async.py
new file mode 100644
index 0000000..87c9a1c
--- /dev/null
+++ b/pexpect/async.py
@@ -0,0 +1,72 @@
+import asyncio
+
+from pexpect import EOF, searcher_re
+
+@asyncio.coroutine
+def expect_async(spawn, pattern):
+    searcher = searcher_re(spawn.compile_pattern_list(pattern))
+
+    def protocol_factory():
+        return PatternWaiter(spawn, searcher)    
+    transport, pw = yield from asyncio.get_event_loop()\
+                        .connect_read_pipe(protocol_factory, spawn)
+    
+    return (yield from pw.fut)
+
+class PatternWaiter(asyncio.Protocol):
+    def __init__(self, spawn, searcher):
+        self.spawn = spawn
+        self.searcher = searcher
+        self.fut = asyncio.Future()
+    
+    def found(self, result):
+        if not self.fut.done():
+            self.fut.set_result(result)
+    
+    def error(self, exc):
+        if not self.fut.done():
+            self.fut.set_exception(exc)
+    
+    def data_received(self, data):
+        spawn = self.spawn
+        s = spawn._coerce_read_string(data)
+        spawn._log(s, 'read')
+        
+        searcher = self.searcher
+        try:
+            incoming = spawn.buffer + s
+            freshlen = len(s)
+            index = searcher.search(incoming, freshlen)
+            if index >= 0:
+                spawn.buffer = incoming[searcher.end:]
+                spawn.before = incoming[: searcher.start]
+                spawn.after = incoming[searcher.start: searcher.end]
+                spawn.match = searcher.match
+                spawn.match_index = index
+                # Found a match
+                self.found(index)
+        except Exception as e:
+            spawn.before = incoming
+            spawn.after = None
+            spawn.match = None
+            spawn.match_index = None
+            self.error(e)
+    
+        spawn.buffer = incoming
+    
+    def eof_received(self):
+        spawn = self.spawn
+        spawn.before = spawn.buffer
+        spawn.buffer = spawn.string_type()
+        spawn.after = EOF
+        index = self.searcher.eof_index
+        if index >= 0:
+            spawn.match = EOF
+            spawn.match_index = index
+            self.found(index)
+        else:
+            spawn.match = None
+            spawn.match_index = None
+            self.error(EOF(str(spawn)))
+
+    
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