hy/hy/mangle.py
2013-04-05 19:29:31 -04:00

110 lines
3.1 KiB
Python

# Copyright (c) 2013 Paul Tagliamonte <paultag@debian.org>
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
from hy.models.expression import HyExpression
# from hy.models.list import HyList
MANGLES = []
class Mangle(object):
"""
Mangle (n.)
1. To mutilate or disfigure by battering, hacking, cutting,
or tearing. See Synonyms at batter1.
(but mostly hacking)
"""
class TreeChanged(Exception):
pass
def _mangle(self, tree):
# Things that force a scope push to go into:
#
# - Functions
# - If
scopable = ["fn", "if"]
scoped = False
self.push_stack(tree)
if isinstance(tree, HyExpression):
what = tree[0]
if what in scopable:
self.push_scope(tree)
scoped = True
if isinstance(tree, list):
for i, element in enumerate(tree):
nel = self.visit(element)
if nel:
tree[i] = nel
self.tree_changed()
self._mangle(element)
if scoped:
self.pop_scope()
self.pop_stack()
def hoist(self, what):
scope = self.scope
for point, el in enumerate(scope):
if el in self.stack:
break
self.scope.insert(point, what)
def get_scope(self):
return self.scopes[0]
def tree_changed(self):
raise self.TreeChanged()
@property
def scope(self):
return self.get_scope()
def push_scope(self, tree):
self.scopes.insert(0, tree)
def push_stack(self, tree):
self.stack.insert(0, tree)
def pop_scope(self):
return self.scopes.pop(0)
def pop_stack(self):
return self.stack.pop(0)
def mangle(self, tree):
unfinished = True
while unfinished:
self.root = tree
self.scopes = []
self.stack = []
self.push_scope(tree)
try:
self._mangle(tree)
unfinished = False
except self.TreeChanged:
pass