Add validate_with to derive(ULE) and derive(VarULE) #2733
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| #[repr(packed)] | ||
| #[derive(ule::ULE, Copy, Clone)] | ||
| #[derive(ule::ULE, Copy, Clone, Debug)] | ||
| #[ule(validate_with = "validate_foo_ule")] |
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nit: this should be zerovec::ule. we do that consistently elsewhere.
It's also fine for it to be zerovec::validate_with, or zerovec(validate_with =) though that last pattern isn't used so far in this crate
| @@ -275,3 +278,43 @@ pub fn extract_attributes_common( | |||
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| Ok(attrs) | |||
| } | |||
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| pub(crate) fn find_validate_with_path( | |||
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issue: This should be a part of the attribute parsing above in extract_attributes_common
| let validate_with = match utils::find_validate_with_path(&input.attrs, &attr_path) { | ||
| Ok(Some(fn_path)) => { | ||
| quote! { | ||
| #fn_path(unsafe { Self::from_byte_slice_unchecked(bytes) })?; |
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thought: for ULE this should be free but for VarULE this will be a couple extra instructions. i suppose we don't care about that?
this way of doing it does make the derive code simpler.
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What are you comparing against?
Note that the case where validate_with is not used, there is no code being added.
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oh, sorry, here we construct an &Self (involving a minor amount of ptr metadata arithmetic) and immediately throw it away, we could theoretically merge it with the last_field_validator but doing that consistently and well will be a mess so it doesn't really matter anyway
sffc
added
the
waiting-on-author
#1691
Note that Serde does this differently using
serde(try_from)(see serde-rs/serde#939). However, since ULE types are dealt with by reference, and there isn't a safe way to transmute&Ato&Transparent<A>, the try_from thing doesn't make sense for ULE. So, I made it avalidate_withfunction instead.If we add a better way to go from
&Ato&Transparent<A>, then we could use thetry_fromthing.