linfa-kernel fails to compile

[avs-origami]

When I try to build the wine quality example for linfa-svm, I get the following error:

   Compiling linfa-kernel v0.6.1
error[E0599]: no method named `mul` found for reference `&CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>` in the current scope
  --> C:\Users\[username]\.cargo\registry\src\index.crates.io-6f17d22bba15001f\linfa-kernel-0.6.1\src\inner.rs:64:14
   |
64 |         self.mul(rhs)
   |              ^^^ method not found in `&CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>`

error[E0599]: no method named `mul` found for reference `&CsMatBase<F, usize, &'a [usize], &'a [usize], &'a [F]>` in the current scope
   --> C:\Users\[username]\.cargo\registry\src\index.crates.io-6f17d22bba15001f\linfa-kernel-0.6.1\src\inner.rs:109:14
    |
109 |         self.mul(rhs)
    |              ^^^ method not found in `&CsMatBase<F, usize, &[usize], &[usize], &[F]>`

For more information about this error, try `rustc --explain E0599`.
error: could not compile `linfa-kernel` (lib) due to 2 previous errors

I am on windows 10 with rustc version 1.70.0. I also tried version 0.5.1 which gives me the same error, and it also happens when I try it on my Arch Linux machine with rustc version 1.68.0.

I looked around in the source files, and it appears that this problem is related to the trait binding of the generic F:

impl<F: linfa::Float> Inner for CsMat<F>

and

impl<'a, F: linfa::Float> Inner for CsMatView<'a, F>

Any help would be appreciated.

[xosxos]

I have the same issue. Seems like CsMat which is imported from sprs cannot implement std::ops:Mul for some reason. Multiplication of a CsMat with an ArrayView2 is the issue which was handled by the std::ops::Mul trait previously from what I can see. But for some reason this is now broken.

[avs-origami]

Yes. I tried creating a new CsMat in a test crate, and I was able to call mul() on it. So I think the issue is related to CsMat not liking linfa::Float as the generic.

[avs-origami]

I changed the start of the impl block to this:

impl<F: Float> Inner for CsMat<F> where 
    CsMat<F>: Mul {
        ...
}

which results in several errors that look like this:

error[E0277]: cannot multiply `CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>` by `CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>`
   --> algorithms/linfa-kernel/src/lib.rs:196:20
    |
196 | impl<'a, F: Float> Kernel<F> {
    |                    ^^^^^^^^^ no implementation for `CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>> * CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>`
    |
    = help: the trait `Mul` is not implemented for `CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>`
    = help: the following other types implement trait `Mul<Rhs>`:
              <&'a CsMatBase<N, I, IpS, IS, DS, Iptr> as Mul<&'b ndarray::ArrayBase<DS2, Dim<[usize; 1]>>>>
              <&'a CsMatBase<N, I, IpS, IS, DS, Iptr> as Mul<&'b ndarray::ArrayBase<DS2, Dim<[usize; 2]>>>>
              <&'a CsMatBase<N, I, IpS1, IS1, DS1, Iptr> as Mul<&'b CsMatBase<N, I, IpS2, IS2, DS2, Iptr>>>
              <&'a CsMatBase<N, I, IpS1, IS1, DS1, Iptr> as Mul<&'b CsVecBase<IS2, DS2, N, I>>>
              <&'a CsMatBase<f32, I, IpStorage, IStorage, DStorage, Iptr> as Mul<f32>>
              <&'a CsMatBase<f64, I, IpStorage, IStorage, DStorage, Iptr> as Mul<f64>>
              <&'a CsMatBase<i16, I, IpStorage, IStorage, DStorage, Iptr> as Mul<i16>>
              <&'a CsMatBase<i32, I, IpStorage, IStorage, DStorage, Iptr> as Mul<i32>>
            and 8 others
note: required for `CsMatBase<F, usize, Vec<usize>, Vec<usize>, Vec<F>>` to implement `Inner`
   --> algorithms/linfa-kernel/src/inner.rs:60:16
    |
60  | impl<F: Float> Inner for CsMat<F> where 
    |                ^^^^^     ^^^^^^^^
61  |     CsMat<F>: Mul {
    |               --- unsatisfied trait bound introduced here

Maybe this helps to diagnose the issue.

[bytesnake]

Could be related to sparsemat/sprs#278

[bytesnake]

This is a regression introduced with the sprs::MulAcc trait in 0.11 https://github.com/sparsemat/sprs/blob/master/changelog.rst Can you try with latest commit?

[avs-origami]

It works now. Thanks!

[jeff-hykin]

I still get this issue. What version is the fix on?

[avs-origami]

You need the latest commit. Instead of this:

linfa-kernel = "0.6.1"

Use this:

linfa-kernel = { git = "https://github.com/rust-ml/linfa.git" }

[jeff-hykin]

Thanks! @avs-origami

[clime]

I;ve just opened sparsemat/sprs#330

[cgubbin]

I'm having this issue again today on linfa 0.7.0.

Thanks to the above I resolved by pinning sprs = "=0.11.1" and everything is compiling again. Would you accept a pull request to pin the sprs version?