implement Base.show for core types

* types: `Constraint`, `ParameterDistribution`

src/ParameterDistributions.jl

@@ -92,6 +92,7 @@ abstract type NoConstraint <: ConstraintType end
 abstract type BoundedBelow <: ConstraintType end
 abstract type BoundedAbove <: ConstraintType end
 abstract type Bounded <: ConstraintType end
+BasicConstraints = Union{BoundedBelow, BoundedAbove, Bounded, NoConstraint}
 
 """
     Constraint{T} <: ConstraintType
@@ -119,6 +120,23 @@ struct Constraint{T} <: ConstraintType
     bounds::Union{Dict, Nothing}
 end
 
+function Base.show(io::IO, ::MIME"text/plain", cons::Constraint{T}) where {T <: BasicConstraints}  # verbose
+    bounds = isnothing(cons.bounds) ? Dict() : cons.bounds
+    lb = get(bounds, "lower_bound", "-∞")
+    ub = get(bounds, "upper_bound", "∞")
+    print(io, "Constraint{$(T)} with bounds ($(lb), $(ub))")
+end
+function Base.show(io::IO, cons::Constraint{T}) where {T}
+    suffix = isnothing(cons.bounds) ? "" : " with characterization $(tuple(cons.bounds...))"
+    print(io, "Constraint{$(T)}" * suffix)
+end
+function Base.show(io::IO, cons::Constraint{<:BasicConstraints})  # shorthand, e.g. in parameter distributions
+    bounds = isnothing(cons.bounds) ? Dict() : cons.bounds
+    lb = get(bounds, "lower_bound", "-∞")
+    ub = get(bounds, "upper_bound", "∞")
+    print(io, "Bounds: ($(lb), $(ub))")
+end
+
 """
     no_constraint()
 
@@ -418,6 +436,19 @@ function ParameterDistribution(
     return ParameterDistribution(distribution, constraint, name)
 end
 
+function Base.show(io::IO, distributions::ParameterDistribution)
+    n = length(distributions.name)
+    out = "ParameterDistribution with $n entries: \n"
+    for (i, inds) in enumerate(batch(distributions))
+        dist = distributions.distribution[i]
+        dist_string = replace("$dist", "\n" => " ")  # hack to remove `\n` from `Parameterized(FullNormal(...))`
+        cons = distributions.constraint[inds]
+        nam = distributions.name[i]
+        out *= "'$(nam)' with $(cons) over distribution $dist_string \n"
+    end
+    print(io, out)
+end
+
 ## Functions
 
 """