Implementing visitor pattern (and toDict) without recursion

esprima/objects.py

@@ -23,58 +23,10 @@
 
 from __future__ import absolute_import, unicode_literals
 
-import re
-import json
-from collections import deque
-
-from .compat import unicode
-
-
-re_type = type(re.compile(r''))
-
 
 def toDict(value):
-    queue = deque()
-
-    def setup(value):
-        if isinstance(value, list):
-            obj = []
-            gen = ((None, v) for v in value)
-        elif isinstance(value, dict):
-            obj = {}
-            gen = ((k, value[k]) for k in value)
-        elif isinstance(value, Object):
-            obj = {}
-            value = value.__dict__
-            gen = ((k, value[k]) for k in value)
-        elif isinstance(value, re_type):
-            obj = {}
-            gen = None
-        else:
-            obj = value
-            gen = None
-        queue.append((obj, gen))
-        return obj
-
-    setup(value)
-
-    while queue:
-        obj, gen = queue[-1]
-
-        if gen is None:
-            queue.pop()
-        else:
-            try:
-                k, value = next(gen)
-            except StopIteration:
-                queue.pop()
-            else:
-                if k is None:
-                    obj.append(setup(value))
-                elif value is not None:
-                    obj[unicode(k)] = setup(value)
-
-    return obj
+    from .visitor import ToDictVisitor
+    return ToDictVisitor().visit(value)
 
 
 class Array(list):
@@ -83,61 +35,12 @@ class Array(list):
 
 class Object(object):
     def toDict(self):
-        return toDict(self.__dict__)
-
-    def repr(self, obj, level=0, indent=4, nl="\n", sp="", skip=(), reprs=()):
-        if isinstance(indent, int):
-            indent = " " * indent
-        indent1 = indent * level
-        indent2 = indent1 + indent
-        if isinstance(obj, Object):
-            obj = obj.__dict__
-        if isinstance(obj, unicode):
-            return json.dumps(obj)
-        if isinstance(obj, list):
-            if not obj:
-                return "[]"
-            return "[%s%s%s%s%s%s%s]" % (
-                sp,
-                nl,
-                indent2,
-                (",%s%s%s" % (nl, sp, indent2)).join(
-                    reprs.get(type(v).__name__, self.repr)(v, level=level + 1, indent=indent, nl=nl, sp=sp, skip=skip, reprs=reprs)
-                    for v in obj
-                ),
-                nl,
-                indent1,
-                sp,
-            )
-        if isinstance(obj, dict):
-            if not obj:
-                return "{}"
-            return "{%s%s%s%s%s%s%s}" % (
-                sp,
-                nl,
-                indent2,
-                (",%s%s%s" % (nl, sp, indent2)).join(
-                    reprs.get(type(v).__name__, self.repr)((k, v), level=level + 1, indent=indent, nl=nl, sp=sp, skip=skip, reprs=reprs)
-                    for k, v in obj.items()
-                    if v is not None and not k.startswith('_') and k not in skip
-                ),
-                nl,
-                indent1,
-                sp,
-            )
-        if isinstance(obj, tuple):
-            k, v = obj
-            return (
-                "%s: %s" % (
-                    k, self.repr(v, level=level, indent=indent, nl=nl, sp=sp, skip=skip, reprs=reprs),
-                )
-            )
-        return repr(obj)
+        from .visitor import ToDictVisitor
+        return ToDictVisitor().visit(self)
 
     def __repr__(self):
-        return self.repr(self, reprs={
-            'SourceLocation': lambda o, **k: self.repr(o, **dict(k, indent="", nl="", sp=" ")),
-        })
+        from .visitor import ReprVisitor
+        return ReprVisitor().visit(self)
 
     def __getattr__(self, name):
         return None