Add == for TruncationStrategys (#211)

* Add `isequal` for `TruncationStrategy`s

* update to `isequal`

* fix formatting

* Update src/algorithms.jl

Co-authored-by: Jutho <Jutho@users.noreply.github.com>

* Update src/algorithms.jl

Co-authored-by: Lukas Devos <ldevos98@gmail.com>

* Update algorithms.jl

---------

Co-authored-by: Jutho <Jutho@users.noreply.github.com>
Co-authored-by: Lukas Devos <ldevos98@gmail.com>

Author: 3 people

src/algorithms.jl

@@ -539,3 +539,7 @@ macro check_size(x, sz, size = :size)
         end
     )
 end
+
+# Check equality of two `TruncationStrategy`s
+Base.:(==)(t1::T, t2::T) where {T <: TruncationStrategy} = all(getfield(t1, f) == getfield(t2, f) for f in fieldnames(T))
+Base.:(==)(t1::T1, t2::T2) where {T1 <: TruncationStrategy, T2 <: TruncationStrategy} = false

test/algorithms.jl

@@ -60,3 +60,23 @@ end
         @test @constinferred(select_algorithm(svd_compact!, A, $alg)) === QRIteration()
     end
 end
+
+@testset "Truncation equivalencies" begin
+    truncs = [
+        notrunc(),
+        truncrank(4),
+        truncrank(5),
+        truncfilter(x -> x > 0),
+        truncfilter(x -> x > 1.0e-4),
+        trunctol(; atol = 0),
+        trunctol(; atol = 1.0e-4),
+        truncerror(; atol = 0),
+        truncerror(; atol = 1.0e-4),
+        truncrank(4) & truncfilter(x -> x > 0),
+        truncrank(4) & truncrank(5),
+    ]
+
+    for (i1, t1) in enumerate(truncs), (i2, t2) in enumerate(truncs)
+        @test (i1 == i2) ? t1 == t2 : t1 != t2
+    end
+end