Registry.from_dict() method, closes #17

README.md

@@ -50,6 +50,21 @@ The HTTP requests to `www.example.com` and `simonwillison.net` will be performed
 
 The library notices that `both()` takes two arguments which are the names of other registered `async def` functions, and will construct an execution plan that executes those two functions in parallel, then passes their results to the `both()` method.
 
+### Registry.from_dict()
+
+Passing a list of functions to the `Registry` constructor will register each function under their introspected function name, using `fn.__name__`.
+
+You can set explicit names instead using a dictionary:
+
+```python
+registry = Registry.from_dict({
+    "example": example,
+    "simonwillison": simonwillison,
+    "both": both
+})
+```
+Those string names will be used to match parameters, so each function will need to accept parameters named after the keys used in that dictionary.
+
 ### Registering additional functions
 
 Functions that are registered can be regular functions or `async def` functions.

asyncinject/__init__.py

@@ -18,6 +18,13 @@ def __init__(self, *fns, parallel=True, timer=None):
         for fn in fns:
             self.register(fn)
 
+    @classmethod
+    def from_dict(cls, d, parallel=True, timer=None):
+        instance = cls(parallel=parallel, timer=timer)
+        for key, fn in d.items():
+            instance.register(fn, name=key)
+        return instance
+
     def register(self, fn, *, name=None):
         self._registry[name or fn.__name__] = fn
         # Clear caches:

asyncinject/vendored_graphlib.py

@@ -169,7 +169,6 @@ def done(self, *nodes):
         n2i = self._node2info
 
         for node in nodes:
-
             # Check if we know about this node (it was added previously using add()
             nodeinfo = n2i.get(node)
             if nodeinfo is None:

tests/test_asyncinject.py

@@ -231,3 +231,23 @@ def three(one, two):
     assert result == 3
 
     assert {t[0] for t in timed} == {"two", "one", "three"}
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("use_string_name", (True, False))
+async def test_registry_from_dict(use_string_name):
+    async def _one():
+        return 1
+
+    async def _two():
+        return 2
+
+    async def _three(one, two):
+        return one + two
+
+    registry = Registry.from_dict({"one": _one, "two": _two, "three": _three})
+    if use_string_name:
+        result = await registry.resolve("three")
+    else:
+        result = await registry.resolve(_three)
+    assert result == 3