Mercurial > repos > shellac > sam_consensus_v3
diff env/lib/python3.9/site-packages/jinja2/optimizer.py @ 0:4f3585e2f14b draft default tip
"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
author | shellac |
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date | Mon, 22 Mar 2021 18:12:50 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.9/site-packages/jinja2/optimizer.py Mon Mar 22 18:12:50 2021 +0000 @@ -0,0 +1,41 @@ +# -*- coding: utf-8 -*- +"""The optimizer tries to constant fold expressions and modify the AST +in place so that it should be faster to evaluate. + +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 scope. The solution would be a second syntax tree +that stored the scoping rules. +""" +from . import nodes +from .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 generic_visit(self, node, *args, **kwargs): + node = super(Optimizer, self).generic_visit(node, *args, **kwargs) + + # Do constant folding. Some other nodes besides Expr have + # as_const, but folding them causes errors later on. + if isinstance(node, nodes.Expr): + try: + return nodes.Const.from_untrusted( + node.as_const(args[0] if args else None), + lineno=node.lineno, + environment=self.environment, + ) + except nodes.Impossible: + pass + + return node