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Diffstat (limited to '')
-rw-r--r-- | sca-java-2.x/tags/2.0-Beta1-RC2/modules/implementation-python-runtime/src/main/resources/util.py | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0-Beta1-RC2/modules/implementation-python-runtime/src/main/resources/util.py b/sca-java-2.x/tags/2.0-Beta1-RC2/modules/implementation-python-runtime/src/main/resources/util.py new file mode 100644 index 0000000000..560101e32d --- /dev/null +++ b/sca-java-2.x/tags/2.0-Beta1-RC2/modules/implementation-python-runtime/src/main/resources/util.py @@ -0,0 +1,145 @@ +# 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. + +# Simple utility functions +from sys import maxint + +# Scheme-like lists +def cons(a, b): + return (a,) + b + +def car(l): + return l[0] + +def first(l): + return car(l) + +def cdr(l): + return l[1:] + +def rest(l): + return cdr(l) + +def cadr(l): + return car(cdr(l)) + +def cddr(l): + return cdr(cdr(l)) + +def caddr(l): + return car(cddr(l)) + +def append(a, b): + return a + b + +def reverse(l): + r = list(l) + r.reverse() + return tuple(r) + +def isNil(l): + if isinstance(l, streampair): + return l.isNil() + return l == () + +def isSymbol(v): + return isinstance(v, basestring) and v[0:1] == "'" + +def isList(v): + if getattr(v, '__iter__', False) == False: + return False + if isinstance(v, basestring) or isinstance(v, dict): + return False + return True + +def isTaggedList(v, t): + return isList(v) and not isNil(v) and car(v) == t + + +# Scheme-like streams +class streampair(object): + def __init__(self, car, cdr): + self.car = car + self.cdr = cdr + + def __repr__(self): + return repr(self[0:len(self)]) + + def isNil(self): + return self.cdr == () + + def __len__(self): + if self.cdr == (): + return 0 + return 1 + len(self.cdr()) + + def __getitem__(self, i): + if i == 0: + return self.car + return self.cdr()[i - 1] + + def __getslice__(self, i, j): + if isNil(self): + return () + if i > 0: + if j == maxint: + return self.cdr()[i - 1: j] + return self.cdr()[i - 1: j - 1] + if j == maxint: + return self + if j == 0: + return (self.car,) + return (self.car,) + self.cdr()[: j - 1] + + def __eq__(self, other): + sl = len(self) + ol = len(other) + if sl != ol: + return False + return self[0: sl] == other[0: ol] + + def __ne__(self, other): + return not self.__eq__(other) + +def cons_stream(car, cdr): + return streampair(car, cdr) + + +# Scheme-like associations +def assoc(k, l): + if l == (): + return None + + if k == car(car(l)): + return car(l) + return assoc(k, cdr(l)) + +# Currying / partial function application +def curry(f, *args): + return lambda *a: f(*(args + a)) + +# Split a path into a list of segments +def tokens(path): + return tuple(filter(lambda s: len(s) != 0, path.split("/"))) + +# Write a list of strings to a stream +def writeStrings(l, os): + if l == (): + return os + os.write(car(l)) + return writeStrings(cdr(l), os) + |