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nodejs/tools/jinja2/optimizer.py
Andrey Lushnikov e0395247c8 inspector: add inspector_protocol as a direct dependency
Currently, node.js depends on inspector_protocol indirectly through the
dependency on v8.

This is a dependency violation that will make it hard to roll V8 into
Node if V8 gets a newer inspector protocol version with incompatible
API. In fact, this surfaced on one of our bots when we tried to roll new
inspector_protocol into V8.

This patch adds inspector protocol and its required dependencies to node
deps:
- jinja2
- markupsafe

PR-URL: https://github.com/nodejs/node/pull/21975
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>
Reviewed-By: Aleksei Koziatinskii <ak239spb@gmail.com>
2018-08-10 18:03:43 -07:00

50 lines
1.7 KiB
Python

# -*- coding: utf-8 -*-
"""
jinja2.optimizer
~~~~~~~~~~~~~~~~
The jinja optimizer is currently trying to constant fold a few expressions
and modify the AST in place so that it should be easier to evaluate it.
Because the AST does not contain all the scoping information and the
compiler has to find that out, we cannot do all the optimizations we
want. For example loop unrolling doesn't work because unrolled loops would
have a different scoping.
The solution would be a second syntax tree that has the scoping rules stored.
:copyright: (c) 2017 by the Jinja Team.
:license: BSD.
"""
from jinja2 import nodes
from jinja2.visitor import NodeTransformer
def optimize(node, environment):
"""The context hint can be used to perform an static optimization
based on the context given."""
optimizer = Optimizer(environment)
return optimizer.visit(node)
class Optimizer(NodeTransformer):
def __init__(self, environment):
self.environment = environment
def fold(self, node, eval_ctx=None):
"""Do constant folding."""
node = self.generic_visit(node)
try:
return nodes.Const.from_untrusted(node.as_const(eval_ctx),
lineno=node.lineno,
environment=self.environment)
except nodes.Impossible:
return node
visit_Add = visit_Sub = visit_Mul = visit_Div = visit_FloorDiv = \
visit_Pow = visit_Mod = visit_And = visit_Or = visit_Pos = visit_Neg = \
visit_Not = visit_Compare = visit_Getitem = visit_Getattr = visit_Call = \
visit_Filter = visit_Test = visit_CondExpr = fold
del fold