| | """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) |
| |
|
| | |
| | |
| | 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 |
| |
|
