add mul! for AbstractTriangular (#153)

Author: mzgubic

src/Test/array.jl

@@ -590,6 +590,27 @@ function triangular_test(x)
             @test MA.iszero!!(z[i, j])
         end
     end
+    v = deepcopy(x[:, 2])
+    m = deepcopy(x)
+    @test MA.isequal_canonical(
+        mul!(deepcopy(v), ut, v),
+        mul!(deepcopy(v), Matrix(ut), v),
+    )
+    @test MA.isequal_canonical(
+        mul!(deepcopy(m), ut, m),
+        mul!(deepcopy(m), Matrix(ut), m),
+    )
+    v = deepcopy(lt[:, 1])
+    m = deepcopy(x)
+    @test MA.isequal_canonical(
+        mul!(deepcopy(v), lt, v),
+        mul!(deepcopy(v), Matrix(lt), v),
+    )
+    @test MA.isequal_canonical(
+        mul!(deepcopy(m), lt, m),
+        mul!(deepcopy(m), Matrix(lt), m),
+    )
+    return
 end
 
 function diagonal_test(x)

src/dispatch.jl

@@ -173,6 +173,14 @@ function LinearAlgebra.mul!(
     return _mul!(ret, A, B)
 end
 
+function LinearAlgebra.mul!(
+    ret::AbstractVector{<:AbstractMutable},
+    A::LinearAlgebra.AbstractTriangular,
+    B::AbstractVector,
+)
+    return _mul!(ret, A, B)
+end
+
 function LinearAlgebra.mul!(
     ret::AbstractMatrix{<:AbstractMutable},
     A::LinearAlgebra.Transpose{<:Any,<:AbstractVecOrMat},
@@ -189,6 +197,14 @@ function LinearAlgebra.mul!(
     return _mul!(ret, A, B)
 end
 
+function LinearAlgebra.mul!(
+    ret::AbstractMatrix{<:AbstractMutable},
+    A::LinearAlgebra.AbstractTriangular,
+    B::AbstractMatrix,
+)
+    return _mul!(ret, A, B)
+end
+
 function LinearAlgebra.mul!(
     ret::AbstractMatrix{<:AbstractMutable},
     A::AbstractMatrix,