Add codec method to retrieve a Go type registered name #316
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Given a codec, users might want to know what's the Amino type associated with a given struct instance. This commit adds the functionality needed to do that, for both instance and pointer-to-instance types. Nil interfaces are rejected by default. Method completed with tests.
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| // if i is a non-nil pointer, dereference it and grab its inner Elem | ||
| if gt.Kind() == reflect.Ptr { | ||
| gt = gt.Elem() |
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What happens if this a **SomeType? (pointer to pointer)
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Uhm, **SomeType would return error even though the struct type has been registered previously.
I could add a check on the inner gt.Elem(), this way it would dereference 2 times and get to the concrete instance.
Thoughts?
Something like:
gt := reflect.TypeOf(i)
for gt.Kind() == reflect.Ptr {
gt = gt.Elem()
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| ct, ok := cdc.typeInfos[gt] | ||
| if !ok { | ||
| return "", fmt.Errorf("no type registered for %s", gt.String()) |
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This should probably be a sentinel error, such that callers can switch over a returned error to see if the type wasn't registered or if any other error occurred.
And independent of that: I think %s already calls String() on the type (no need to explicitly call it here).
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Would those two errors be okay for the purpose?
ErrNilPointer, wheniisnil;ErrTypeNotRegistered, when the concrete type ofiis not registered;
Yup, String() will be removed :-)
Given a codec, users might want to know what's the Amino type associated
with a given struct instance.
This commit adds the functionality needed to do that, for both instance and pointer-to-instance
types.
Nil interfaces are rejected by default.
Method completed with tests.
We are in the process of writing various SDKs for our project (commercionetwork), and for the Go one we thought it might be a great idea to simply reuse all the types implemented in our modules.
We need to know at runtime Amino message types for every possible type in order to construct a well-defined Cosmos REST transaction message.
Right now, we manually parse
codec.PrintTypes()output and build a map which associates Go type to its Amino name.This patch integrates basically the same idea, by leveraging the codec's integrated type map.