python上的微型抽象数据类型
miniadt的Python项目详细描述
如何使用
## create Type
>>> from miniadt import ADTTypeProvider
>>> TreeType = ADTTypeProvider("Tree")
>>> Node = TreeType("Node", "e children")
>>> Leaf = TreeType("Leaf", "e")
## printing value
>>> Leaf(e=10)
Leaf(e=10)
>>> Node(e=10, children=[Leaf(e=20)])
Node(e=10, children=[Leaf(e=20)])
## use pattern match
>>> @TreeType.match
... class depth(object):
... def Node(e, children):
... return max(depth(e)for e in children) + 1
...
... def Leaf(e):
... return 1
>>> depth(Leaf(e=10))
1
>>> depth(Node(e=10, children=[Leaf(e=20), Node(e=30, children=[Leaf(e=40)])]))
3
miniadt具有全面的检查功能。
## not comprehensive definition on pattern matching function error is occur ### 1. lack of dispatch andidates >>> class invalid_dispatch(object): ... def Node(e, children): ... return "foo" >>> TreeType.match(invalid_dispatch) Traceback (most recent call last): ... miniadt.NotComprehensive: Leaf is not found. expected=['Node', 'Leaf'] ### 2. dispatch function's arguments are invalid. >>> class invalid_dispatch2(object): ... def Node(e): ## correct argsspec is "e, children" ... return "foo" ... def Leaf(e): ... return "foo" >>> TreeType.match(invalid_dispatch2) Traceback (most recent call last): ... miniadt.NotComprehensive: on Tree.Node: expected=['e', 'children'] != actual=['e']
类似功能
- 匹配
- 匹配实例
- 分类
fromminiadtimportADTTypeProviderTree=ADTTypeProvider("Tree")Node=Tree("Node","e children")Leaf=Tree("Leaf","e")print(Leaf(e=10))# => Leaf(e=10)print(Node(e=10,children=[Leaf(e=20)]))# => Node(e=10, children=[Leaf(e=20)])@Tree.matchclassdepth(object):defLeaf(e):return1defNode(e,children):returnmax(depth(e)foreinchildren)+1print(depth(Leaf(e=10)))# => 10print(depth(Node(e=10,children=[Leaf(e=20)])))# 2@Tree.match_instanceclassApplicator(object):def__init__(self,name):self.name=namedefLeaf(self,e):returnself.namedefNode(self,e,children):return[self.name,[self(x)forxinchildren]]print(Applicator("foo")(Leaf(e=10)))# => fooprint(Applicator("foo")(Node(e=10,children=[Leaf(e=20)])))# => ['foo', ['foo']]@Tree.classifyclassToDict(object):defLeaf(self,leaf):returnleaf.edefNode(self,node):return{"e":node.e,"children":[self(e)foreinnode.children]}todict=ToDict()print(todict(Leaf(e=10)))# => 10print(todict(Node(e=10,children=[Leaf(e=20)])))# => {'e': 10, 'children': [20]}
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