switched API over to select based driver; added address parser

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@818075 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 140 insertions, 0 deletions

diff --git a/python/qpid/address.py b/python/qpid/address.py
new file mode 100644
index 0000000000..18e8284e4d
--- /dev/null
+++ b/python/qpid/address.py
@@ -0,0 +1,140 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+#
+import re
+
+TYPES = []
+
+class Type:
+
+  def __init__(self, name, pattern=None):
+    self.name = name
+    self.pattern = pattern
+    if self.pattern:
+      TYPES.append(self)
+
+  def __repr__(self):
+    return self.name
+
+LBRACE = Type("LBRACE", r"\{")
+RBRACE = Type("RBRACE", r"\}")
+COLON = Type("COLON", r":")
+COMMA = Type("COMMA", r",")
+ID = Type("ID", r'[a-zA-Z_][a-zA-Z0-9_]*')
+NUMBER = Type("NUMBER", r'[+-]?[0-9]*\.?[0-9]+')
+STRING = Type("STRING", r""""(?:[^\\"]|\\.)*"|'(?:[^\\']|\\.)*'""")
+WSPACE = Type("WSPACE", r"[ \n\r\t]+")
+EOF = Type("EOF")
+
+class Token:
+
+  def __init__(self, type, value):
+    self.type = type
+    self.value = value
+
+  def __repr__(self):
+    return "%s: %r" % (self.type, self.value)
+
+joined = "|".join(["(%s)" % t.pattern for t in TYPES])
+LEXER = re.compile(joined)
+
+def lex(st):
+  pos = 0
+  while pos < len(st):
+    m = LEXER.match(st, pos)
+    if m is None:
+      raise ValueError(repr(st[pos:]))
+    else:
+      idx = m.lastindex
+      t = Token(TYPES[idx - 1], m.group(idx))
+      yield t
+    pos = m.end()
+  yield Token(EOF, None)
+
+class ParseError(Exception): pass
+
+class EOF(Exception): pass
+
+class Parser:
+
+  def __init__(self, tokens):
+    self.tokens = [t for t in tokens if t.type is not WSPACE]
+    self.idx = 0
+
+  def next(self):
+    return self.tokens[self.idx]
+
+  def matches(self, *types):
+    return self.next().type in types
+
+  def eat(self, *types):
+    if types and not self.matches(*types):
+      raise ParseError("expecting %s -- got %s" % (", ".join(map(str, types)), self.next()))
+    else:
+      t = self.next()
+      self.idx += 1
+      return t
+
+  def parse(self):
+    result = self.address()
+    self.eat(EOF)
+    return result
+
+  def address(self):
+    name = self.eat(ID).value
+    if self.matches(LBRACE):
+      options = self.map()
+    else:
+      options = None
+    return name, options
+
+  def map(self):
+    self.eat(LBRACE)
+    result = {}
+    while True:
+      if self.matches(RBRACE):
+        self.eat(RBRACE)
+        break
+      else:
+        if self.matches(ID):
+          n, v = self.nameval()
+          result[n] = v
+        elif self.matches(COMMA):
+          self.eat(COMMA)
+        else:
+          raise ParseError("expecting (ID, COMMA), got %s" % self.next())
+    return result
+
+  def nameval(self):
+    name = self.eat(ID).value
+    self.eat(COLON)
+    val = self.value()
+    return (name, val)
+
+  def value(self):
+    if self.matches(NUMBER, STRING):
+      return eval(self.eat().value)
+    elif self.matches(LBRACE):
+      return self.map()
+    else:
+      raise ParseError("expecting (NUMBER, STRING, LBRACE) got %s" % self.next())
+
+def parse(addr):
+  return Parser(lex(addr)).parse()
+
+__all__ = ["parse"]