Implement if let expressions and associated fixes
#815
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if let expressionsif let expressions and associated fixes
| } => { | ||
| // sorry | ||
| let leaked_ix: &'static str = Box::leak(Box::new(elem_to_access_num.to_string())); | ||
| let access_ident = Ident::new_with_override(leaked_ix, elem_to_access_span.clone()); |
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Obviously less than ideal. Should we make an issue to not need 'static strings for Ident?
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I'm not sure. I was debating the performance costs. We clone Ident a lot throughout the compiler. I somewhat suspect that this leak is better for performance than using String everywhere for Ident. And using a scoped lifetime, like <'sc>, would be what we had before and nobody liked that.
This only happens specifically in these tuple accesses. I'm sure we can sort out a more localized solution that just updates the tuple access stuff. Maybe that's what the issue should be about.
test/src/e2e_vm_tests/test_programs/chained_if_let_missing_branch/Forc.toml
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Yikes, are we going to get |
All of the I think this is a unique case where the conflicts are potentially related to generating and committing lock files between #825 landing and #876 landing. I probably should have done #876 as a part of #825 to avoid this happening, but that PR was already massive enough! I would probably address this via a rebase onto master, but I know many prefer to avoid rebase and everyone has their own git wrangling strats :) |
test/src/e2e_vm_tests/test_programs/enum_destructuring/Forc.toml
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Do not merge until 0.6.1 is released #921 |
Why?
As we don't have any form of destructuring, getting values out of enums is impossible. This hinders our progress in developing the standard library and basic demos -- primarily SwaySwap.
What?
This PR implements
if letfor enums, although not to complete parity with Rust's pattern matching. Some general fixes around generic types/enums/etc., are included in this PR as well.List O' Changes
return statements inside of if expressions were not being type checked correctly. This PR fixes that.if letexpressions, which compare an enum's tag and conditionally pull out its contents into a variable.
afer
7. Improved dead code detection such that publicly exported enums don't warn that their variants are unused. 8. Allow type annotations for enum instantiations, i.e. `let x = Result::Ok::(5u64)`Remaining work
implblocks and trait interactions are still not there. This PR was big enough as is, so that'll be coming later.if letonly allows for destructuring the top-level enum. This is okay:if let Result::Ok(val) = foo { .. }, this is not okay:if let Result::Ok(Option::Some(Enum::Variant(x, y, Struct { field, .. } ) ) ) = foo { .. }closes #817
closes #624