Mercurial > repos > guerler > springsuite
comparison planemo/lib/python3.7/site-packages/jinja2/optimizer.py @ 1:56ad4e20f292 draft
"planemo upload commit 6eee67778febed82ddd413c3ca40b3183a3898f1"
author | guerler |
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date | Fri, 31 Jul 2020 00:32:28 -0400 |
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0:d30785e31577 | 1:56ad4e20f292 |
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1 # -*- coding: utf-8 -*- | |
2 """The optimizer tries to constant fold expressions and modify the AST | |
3 in place so that it should be faster to evaluate. | |
4 | |
5 Because the AST does not contain all the scoping information and the | |
6 compiler has to find that out, we cannot do all the optimizations we | |
7 want. For example, loop unrolling doesn't work because unrolled loops | |
8 would have a different scope. The solution would be a second syntax tree | |
9 that stored the scoping rules. | |
10 """ | |
11 from . import nodes | |
12 from .visitor import NodeTransformer | |
13 | |
14 | |
15 def optimize(node, environment): | |
16 """The context hint can be used to perform an static optimization | |
17 based on the context given.""" | |
18 optimizer = Optimizer(environment) | |
19 return optimizer.visit(node) | |
20 | |
21 | |
22 class Optimizer(NodeTransformer): | |
23 def __init__(self, environment): | |
24 self.environment = environment | |
25 | |
26 def generic_visit(self, node, *args, **kwargs): | |
27 node = super(Optimizer, self).generic_visit(node, *args, **kwargs) | |
28 | |
29 # Do constant folding. Some other nodes besides Expr have | |
30 # as_const, but folding them causes errors later on. | |
31 if isinstance(node, nodes.Expr): | |
32 try: | |
33 return nodes.Const.from_untrusted( | |
34 node.as_const(args[0] if args else None), | |
35 lineno=node.lineno, | |
36 environment=self.environment, | |
37 ) | |
38 except nodes.Impossible: | |
39 pass | |
40 | |
41 return node |