Coverage for /var/srv/projects/api.amasfac.comuna18.com/tmp/venv/lib/python3.9/site-packages/jinja2/optimizer.py: 44%

1"""The optimizer tries to constant fold expressions and modify the AST 

2in place so that it should be faster to evaluate. 

3 

4Because the AST does not contain all the scoping information and the 

5compiler has to find that out, we cannot do all the optimizations we 

6want. For example, loop unrolling doesn't work because unrolled loops 

7would have a different scope. The solution would be a second syntax tree 

8that stored the scoping rules. 

9""" 

10import typing as t 

11 

12from . import nodes 

13from .visitor import NodeTransformer 

14 

15if t.TYPE_CHECKING: 15 ↛ 16line 15 didn't jump to line 16, because the condition on line 15 was never true

16 from .environment import Environment 

17 

18 

19def optimize(node: nodes.Node, environment: "Environment") -> nodes.Node: 

20 """The context hint can be used to perform an static optimization 

21 based on the context given.""" 

22 optimizer = Optimizer(environment) 

23 return t.cast(nodes.Node, optimizer.visit(node)) 

24 

25 

26class Optimizer(NodeTransformer): 

27 def __init__(self, environment: "t.Optional[Environment]") -> None: 

28 self.environment = environment 

29 

30 def generic_visit( 

31 self, node: nodes.Node, *args: t.Any, **kwargs: t.Any 

32 ) -> nodes.Node: 

33 node = super().generic_visit(node, *args, **kwargs) 

34 

35 # Do constant folding. Some other nodes besides Expr have 

36 # as_const, but folding them causes errors later on. 

37 if isinstance(node, nodes.Expr): 

38 try: 

39 return nodes.Const.from_untrusted( 

40 node.as_const(args[0] if args else None), 

41 lineno=node.lineno, 

42 environment=self.environment, 

43 ) 

44 except nodes.Impossible: 

45 pass 

46 

47 return node