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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /third_party/python/Jinja2/jinja2/optimizer.py
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/python/Jinja2/jinja2/optimizer.py')
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diff --git a/third_party/python/Jinja2/jinja2/optimizer.py b/third_party/python/Jinja2/jinja2/optimizer.py
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+"""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.
+"""
+import typing as t
+
+from . import nodes
+from .visitor import NodeTransformer
+
+if t.TYPE_CHECKING:
+ from .environment import Environment
+
+
+def optimize(node: nodes.Node, environment: "Environment") -> nodes.Node:
+ """The context hint can be used to perform an static optimization
+ based on the context given."""
+ optimizer = Optimizer(environment)
+ return t.cast(nodes.Node, optimizer.visit(node))
+
+
+class Optimizer(NodeTransformer):
+ def __init__(self, environment: "t.Optional[Environment]") -> None:
+ self.environment = environment
+
+ def generic_visit(
+ self, node: nodes.Node, *args: t.Any, **kwargs: t.Any
+ ) -> nodes.Node:
+ node = super().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