"ins" and "out" arguments for @graph

@op has the ins and out arguments for specifying inputs and outputs, which accept Ins and Outs, but @graph still has input_defs and output_defs arguments that accept InputDefinitions and OutputDefinitions.

We should make these consistent. Also, we’ve discussed eliminating the default_value and dagster_type attrs of graph input/output defs, because they’re hard to reason about and provide questionable value.

Could look something like:

@graph(ins={"arg1": GraphIn(description="abc")}, out=GraphOut(description="xyz"))
def my_graph(arg1):
    ...

[alangenfeld]

Graph__ feels off naming wise to me. These are ultimately input & output mappings when they exist on graphs, so maybe something like:

• MappedIn
• MapIn
• Mapped / Mapping (if theres no arg difference between in and out)

[alangenfeld]

only if, in the body of the decorated function, it’s passed as an input to a node invocation, then it will be mapped

For what its worth, I’m fairly sure we error if it doesn’t get mapped.

That said, I still find your reasoning compelling. Not really happy with these, but throwing them around to help brain storm: Spec, Props, Expose