diff options
Diffstat (limited to 'Lib/compiler')
| -rw-r--r-- | Lib/compiler/visitor.py | 54 |
1 files changed, 22 insertions, 32 deletions
diff --git a/Lib/compiler/visitor.py b/Lib/compiler/visitor.py index 7392662..d0e5223 100644 --- a/Lib/compiler/visitor.py +++ b/Lib/compiler/visitor.py @@ -47,31 +47,19 @@ class ASTVisitor: self._preorder(tree) def _preorder(self, node, *args): - stop = apply(self.dispatch, (node,) + args) - if stop: - return - for child in node.getChildren(): - if isinstance(child, ast.Node): - self._preorder(child) - - def postorder(self, tree, visitor): - """Do preorder walk of tree using visitor""" - self.visitor = visitor - visitor.visit = self._postorder - self._postorder(tree) + return apply(self.dispatch, (node,) + args) - def _postorder(self, tree, *args): + def default(self, node, *args): for child in node.getChildren(): if isinstance(child, ast.Node): - self._postorder(child) - apply(self.dispatch, (node,) + args) + apply(self._preorder, (child,) + args) 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) + meth = getattr(self.visitor, 'visit' + className, self.default) self._cache[node.__class__] = meth if self.VERBOSE > 0: if self.VERBOSE == 1: @@ -79,8 +67,7 @@ class ASTVisitor: print "dispatch", className else: print "dispatch", className, (meth and meth.__name__ or '') - if meth: - return apply(meth, (node,) + args) + return apply(meth, (node,) + args) class ExampleASTVisitor(ASTVisitor): """Prints examples of the nodes that aren't visited @@ -93,24 +80,27 @@ class ExampleASTVisitor(ASTVisitor): def dispatch(self, node, *args): self.node = node - className = node.__class__.__name__ - meth = getattr(self.visitor, 'visit' + className, None) - if self.VERBOSE > 0: - if self.VERBOSE > 1: - print "dispatch", className, (meth and meth.__name__ or '') + 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: return apply(meth, (node,) + args) elif self.VERBOSE > 0: klass = node.__class__ - if self.examples.has_key(klass): - return - self.examples[klass] = klass - print - print klass - for attr in dir(node): - if attr[0] != '_': - print "\t", "%-12.12s" % attr, getattr(node, attr) - print + 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 apply(self.default, (node,) + args) _walker = ASTVisitor def walk(tree, visitor, verbose=None): |