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author | Ori Bernstein <ori@eigenstate.org> | 2021-06-14 00:00:37 +0000 |
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committer | Ori Bernstein <ori@eigenstate.org> | 2021-06-14 00:00:37 +0000 |
commit | a73a964e51247ed169d322c725a3a18859f109a3 (patch) | |
tree | 3f752d117274d444bda44e85609aeac1acf313f3 /sys/lib/python/compiler/visitor.py | |
parent | e64efe273fcb921a61bf27d33b230c4e64fcd425 (diff) |
python, hg: tow outside the environment.
they've served us well, and can ride off into the sunset.
Diffstat (limited to 'sys/lib/python/compiler/visitor.py')
-rw-r--r-- | sys/lib/python/compiler/visitor.py | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/sys/lib/python/compiler/visitor.py b/sys/lib/python/compiler/visitor.py deleted file mode 100644 index 9e39d3664..000000000 --- a/sys/lib/python/compiler/visitor.py +++ /dev/null @@ -1,113 +0,0 @@ -from compiler import ast - -# XXX should probably rename ASTVisitor to ASTWalker -# XXX can it be made even more generic? - -class ASTVisitor: - """Performs a depth-first walk of the AST - - The ASTVisitor will walk the AST, performing either a preorder or - postorder traversal depending on which method is called. - - methods: - preorder(tree, visitor) - postorder(tree, visitor) - tree: an instance of ast.Node - visitor: an instance with visitXXX methods - - The ASTVisitor is responsible for walking over the tree in the - correct order. For each node, it checks the visitor argument for - a method named 'visitNodeType' where NodeType is the name of the - node's class, e.g. Class. If the method exists, it is called - with the node as its sole argument. - - The visitor method for a particular node type can control how - child nodes are visited during a preorder walk. (It can't control - the order during a postorder walk, because it is called _after_ - the walk has occurred.) The ASTVisitor modifies the visitor - argument by adding a visit method to the visitor; this method can - be used to visit a child node of arbitrary type. - """ - - VERBOSE = 0 - - def __init__(self): - self.node = None - self._cache = {} - - def default(self, node, *args): - for child in node.getChildNodes(): - self.dispatch(child, *args) - - def dispatch(self, node, *args): - self.node = node - klass = node.__class__ - meth = self._cache.get(klass, None) - if meth is None: - className = klass.__name__ - meth = getattr(self.visitor, 'visit' + className, self.default) - self._cache[klass] = meth -## if self.VERBOSE > 0: -## className = klass.__name__ -## if self.VERBOSE == 1: -## if meth == 0: -## print "dispatch", className -## else: -## print "dispatch", className, (meth and meth.__name__ or '') - return meth(node, *args) - - def preorder(self, tree, visitor, *args): - """Do preorder walk of tree using visitor""" - self.visitor = visitor - visitor.visit = self.dispatch - self.dispatch(tree, *args) # XXX *args make sense? - -class ExampleASTVisitor(ASTVisitor): - """Prints examples of the nodes that aren't visited - - This visitor-driver is only useful for development, when it's - helpful to develop a visitor incrementally, and get feedback on what - you still have to do. - """ - examples = {} - - def dispatch(self, node, *args): - self.node = node - meth = self._cache.get(node.__class__, None) - className = node.__class__.__name__ - if meth is None: - meth = getattr(self.visitor, 'visit' + className, 0) - self._cache[node.__class__] = meth - if self.VERBOSE > 1: - print "dispatch", className, (meth and meth.__name__ or '') - if meth: - meth(node, *args) - elif self.VERBOSE > 0: - klass = node.__class__ - if not self.examples.has_key(klass): - self.examples[klass] = klass - print - print self.visitor - print klass - for attr in dir(node): - if attr[0] != '_': - print "\t", "%-12.12s" % attr, getattr(node, attr) - print - return self.default(node, *args) - -# XXX this is an API change - -_walker = ASTVisitor -def walk(tree, visitor, walker=None, verbose=None): - if walker is None: - walker = _walker() - if verbose is not None: - walker.VERBOSE = verbose - walker.preorder(tree, visitor) - return walker.visitor - -def dumpNode(node): - print node.__class__ - for attr in dir(node): - if attr[0] != '_': - print "\t", "%-10.10s" % attr, getattr(node, attr) |