https://discuss.python.org/t/pep-750-tag-strings-for-writing-domain-specific-languages/60408

eager.py

#!/usr/bin/env python
from functools import wraps

class Interpolation:
    def __init__(self, getvalue):
        self.getvalue = getvalue

def eager_tag(func):
    @wraps(func)
    def wrapper(*args):
        newargs = []
        for arg in args:
            match arg:
                case Interpolation() as ip:
                    # Avoiding binding issues
                    newargs.append(
                        Interpolation( (lambda v: lambda: v)(ip.getvalue()) )
                    )
                case other:
                    newargs.append(other)
        return func(*newargs)
    return wrapper

@eager_tag
def lazy(*args):
    def _lazy():
        for arg in args:
            match arg:
                case Interpolation() as ip:
                    print(ip.getvalue())
                case other:
                    print(other)
    return _lazy

a,b = 1,2
l = lazy(
    'a', Interpolation(lambda: a),
    'b', Interpolation(lambda: b),
)
a,b = 3,4
l()