Fix show of Face and Cell values

src/FEValues/cell_values.jl

@@ -285,3 +285,11 @@ function reinit!(cv::CellValues{<:Any, N_t, dNdx_t, dNdξ_t}, x::AbstractVector{
     end
     return nothing
 end
+
+function Base.show(io::IO, m::MIME"text/plain", cv::CellValues)
+    println(io, "CellValues with")
+    println(io, "- Quadrature rule with ", getnquadpoints(cv), " points")
+    print(io, "- Function interpolation: "); show(io, m, cv.ip)
+    println(io)
+    print(io, "- Geometric interpolation: "); show(io, m, cv.gip)
+end

src/FEValues/face_values.jl

@@ -250,3 +250,16 @@ function checkface(fv::FaceValues, face::Int)
     0 < face <= nfaces(fv) || error("Face index out of range.")
     return nothing
 end
+
+function Base.show(io::IO, m::MIME"text/plain", fv::FaceValues)
+    println(io, "FaceValues with")
+    nqp = getnquadpoints.(fv.qr.face_rules)
+    if all(n==first(nqp) for n in nqp)
+        println(io, "- Quadrature rule with ", first(nqp), " points per face")
+    else
+        println(io, "- Quadrature rule with ", tuple(nqp...), " points on each face")
+    end
+    print(io, "- Function interpolation: "); show(io, m, fv.func_interp)
+    println(io)
+    print(io, "- Geometric interpolation: "); show(io, m, fv.geo_interp)
+end

test/test_cellvalues.jl

@@ -308,4 +308,10 @@ end
     end
 end
 
+@testset "show" begin
+    # Just smoke test
+    cv = CellValues(QuadratureRule{RefQuadrilateral}(2), Lagrange{RefQuadrilateral,2}())
+    show(stdout, MIME"text/plain"(), cv)
+end
+
 end # of testset

test/test_facevalues.jl

@@ -107,4 +107,13 @@ for (scalar_interpol, quad_rule) in (
     end
 end
 
+@testset "show" begin
+    # Just smoke test to make sure show doesn't error. 
+    fv = FaceValues(FaceQuadratureRule{RefQuadrilateral}(2), Lagrange{RefQuadrilateral,2}())
+    show(stdout, MIME"text/plain"(), fv)
+    fv.qr.face_rules[1] = deepcopy(fv.qr.face_rules[1])
+    push!(Ferrite.getweights(fv.qr.face_rules[1]), 1)
+    show(stdout, MIME"text/plain"(), fv)
+end
+
 end # of testset