Add Base.show for integration rules (#189)

* add Base.show for integration rules

* add _kwargs_to_string function

Author: JoshuaLampert

src/integration_rules.jl

@@ -2,6 +2,10 @@
 #                           Integration Rules
 ################################################################################
 
+function _kwargs_to_string(kwargs)
+    return join([string(k) * " = " * string(v) for (k, v) in pairs(kwargs)], ", ")
+end
+
 abstract type IntegrationRule end
 
 """
@@ -18,6 +22,10 @@ struct GaussKronrod <: IntegrationRule
     GaussKronrod(; kwargs...) = new(kwargs)
 end
 
+function Base.show(io::IO, rule::GaussKronrod)
+    print(io, "GaussKronrod(; ", _kwargs_to_string(rule.kwargs), ")")
+end
+
 """
     GaussLegendre(n)
 
@@ -39,6 +47,10 @@ struct GaussLegendre <: IntegrationRule
     GaussLegendre(n::Int64) = new(n, FastGaussQuadrature.gausslegendre(n)...)
 end
 
+function Base.show(io::IO, rule::GaussLegendre)
+    print(io, "GaussLegendre(", rule.n, ")")
+end
+
 """
     HAdaptiveCubature(kwargs...)
 
@@ -50,3 +62,7 @@ struct HAdaptiveCubature <: IntegrationRule
     kwargs::Base.Pairs
     HAdaptiveCubature(; kwargs...) = new(kwargs)
 end
+
+function Base.show(io::IO, rule::HAdaptiveCubature)
+    print(io, "HAdaptiveCubature(; ", _kwargs_to_string(rule.kwargs), ")")
+end

test/utils.jl

@@ -7,6 +7,14 @@
     import Enzyme
 end
 
+@testitem "Integration Rules" begin
+    @test sprint(show, GaussKronrod(; atol = 1e-12, rtol = 1e-10)) ==
+          "GaussKronrod(; atol = 1.0e-12, rtol = 1.0e-10)"
+
+    @test sprint(show, GaussLegendre(5)) == "GaussLegendre(5)"
+    @test sprint(show, HAdaptiveCubature()) == "HAdaptiveCubature(; )"
+end
+
 @testitem "Utilities" setup=[Utils] begin
     # _KVector
     v = Meshes.Vec(3, 4)