From 27c7fa11230424c59c61d45b9957e89afe1e4032 Mon Sep 17 00:00:00 2001
From: Toshiki Teramura <toshiki.teramura@gmail.com>
Date: Mon, 3 Oct 2022 21:56:16 +0900
Subject: [PATCH] Merge Triangular_ into Lapack

---
 lax/src/lib.rs        | 26 +++++++++++++++++++++++---
 lax/src/triangular.rs | 26 +++++++++++++++++---------
 2 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/lax/src/lib.rs b/lax/src/lib.rs
index 4989fe15..4e886ea4 100644
--- a/lax/src/lib.rs
+++ b/lax/src/lib.rs
@@ -100,9 +100,9 @@ pub mod solve;
 pub mod solveh;
 pub mod svd;
 pub mod svddc;
+pub mod triangular;
 
 mod alloc;
-mod triangular;
 mod tridiagonal;
 
 pub use self::cholesky::*;
@@ -110,7 +110,6 @@ pub use self::flags::*;
 pub use self::least_squares::LeastSquaresOwned;
 pub use self::opnorm::*;
 pub use self::svd::{SvdOwned, SvdRef};
-pub use self::triangular::*;
 pub use self::tridiagonal::*;
 
 use self::{alloc::*, error::*, layout::*};
@@ -121,7 +120,7 @@ pub type Pivot = Vec<i32>;
 
 #[cfg_attr(doc, katexit::katexit)]
 /// Trait for primitive types which implements LAPACK subroutines
-pub trait Lapack: Triangular_ + Tridiagonal_ {
+pub trait Lapack: Tridiagonal_ {
     /// Compute right eigenvalue and eigenvectors for a general matrix
     fn eig(
         calc_v: bool,
@@ -298,6 +297,15 @@ pub trait Lapack: Triangular_ + Tridiagonal_ {
     ///   $$
     ///
     fn opnorm(t: NormType, l: MatrixLayout, a: &[Self]) -> Self::Real;
+
+    fn solve_triangular(
+        al: MatrixLayout,
+        bl: MatrixLayout,
+        uplo: UPLO,
+        d: Diag,
+        a: &[Self],
+        b: &mut [Self],
+    ) -> Result<()>;
 }
 
 macro_rules! impl_lapack {
@@ -471,6 +479,18 @@ macro_rules! impl_lapack {
                 let mut work = OperatorNormWork::<$s>::new(t, l);
                 work.calc(a)
             }
+
+            fn solve_triangular(
+                al: MatrixLayout,
+                bl: MatrixLayout,
+                uplo: UPLO,
+                d: Diag,
+                a: &[Self],
+                b: &mut [Self],
+            ) -> Result<()> {
+                use triangular::*;
+                SolveTriangularImpl::solve_triangular(al, bl, uplo, d, a, b)
+            }
         }
     };
 }
diff --git a/lax/src/triangular.rs b/lax/src/triangular.rs
index 14f29807..da4dc4cf 100644
--- a/lax/src/triangular.rs
+++ b/lax/src/triangular.rs
@@ -1,10 +1,18 @@
-//! Implement linear solver and inverse matrix
+//! Linear problem for triangular matrices
 
 use crate::{error::*, layout::*, *};
 use cauchy::*;
 
-/// Wraps `*trtri` and `*trtrs`
-pub trait Triangular_: Scalar {
+/// Solve linear problem for triangular matrices
+///
+/// LAPACK correspondance
+/// ----------------------
+///
+/// | f32    | f64    | c32    | c64    |
+/// |:-------|:-------|:-------|:-------|
+/// | strtrs | dtrtrs | ctrtrs | ztrtrs |
+///
+pub trait SolveTriangularImpl: Scalar {
     fn solve_triangular(
         al: MatrixLayout,
         bl: MatrixLayout,
@@ -16,8 +24,8 @@ pub trait Triangular_: Scalar {
 }
 
 macro_rules! impl_triangular {
-    ($scalar:ty, $trtri:path, $trtrs:path) => {
-        impl Triangular_ for $scalar {
+    ($scalar:ty, $trtrs:path) => {
+        impl SolveTriangularImpl for $scalar {
             fn solve_triangular(
                 a_layout: MatrixLayout,
                 b_layout: MatrixLayout,
@@ -79,7 +87,7 @@ macro_rules! impl_triangular {
     };
 } // impl_triangular!
 
-impl_triangular!(f64, lapack_sys::dtrtri_, lapack_sys::dtrtrs_);
-impl_triangular!(f32, lapack_sys::strtri_, lapack_sys::strtrs_);
-impl_triangular!(c64, lapack_sys::ztrtri_, lapack_sys::ztrtrs_);
-impl_triangular!(c32, lapack_sys::ctrtri_, lapack_sys::ctrtrs_);
+impl_triangular!(f64, lapack_sys::dtrtrs_);
+impl_triangular!(f32, lapack_sys::strtrs_);
+impl_triangular!(c64, lapack_sys::ztrtrs_);
+impl_triangular!(c32, lapack_sys::ctrtrs_);