Implement print for MOI.ModelLike

Project.toml

@@ -11,6 +11,7 @@ JSONSchema = "7d188eb4-7ad8-530c-ae41-71a32a6d4692"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MutableArithmetics = "d8a4904e-b15c-11e9-3269-09a3773c0cb0"
 OrderedCollections = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
+Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Unicode = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"

docs/src/submodules/Utilities/overview.md

@@ -265,6 +265,52 @@ with model cache MOIU.GenericModel{Float64,MOIU.ModelFunctionConstraints{Float64
 with optimizer MOIU.GenericOptimizer{Float64,MOIU.VectorOfConstraints{MOI.VectorAffineFunction{Float64},MOI.Complements}}
 ```
 
+## Printing
+
+Use `print` to print the formulation of the model.
+```jldoctest utilities_print
+julia> model = MOI.Utilities.Model{Float64}();
+
+julia> x = MOI.add_variable(model)
+MathOptInterface.VariableIndex(1)
+
+julia> MOI.set(model, MOI.VariableName(), x, "x_var")
+
+julia> f = MOI.SingleVariable(x)
+MathOptInterface.SingleVariable(MathOptInterface.VariableIndex(1))
+
+julia> MOI.add_constraint(model, f, MOI.ZeroOne())
+MathOptInterface.ConstraintIndex{MathOptInterface.SingleVariable,MathOptInterface.ZeroOne}(1)
+
+julia> MOI.set(model, MOI.ObjectiveFunction{typeof(f)}(), f)
+
+julia> MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+
+julia> print(model)
+Maximize SingleVariable:
+ x_var
+
+Subject to:
+
+SingleVariable-in-ZeroOne
+ x_var ∈ {0, 1}
+```
+
+Use [`Utilities.latex_formulation`](@Ref) to display the model in LaTeX form:
+```jldoctest utilities_print
+julia> MOI.Utilities.latex_formulation(model)
+$$ \begin{aligned}
+\max\quad & x\_var \\
+\text{Subject to}\\
+ & \text{SingleVariable-in-ZeroOne} \\
+ & x\_var \in \{0, 1\} \\
+\end{aligned} $$
+```
+
+!!! tip
+    In IJulia, calling `print` or ending a cell with
+    [`Utilities.latex_formulation`](@ref) will render the model in LaTex.
+
 ## Copy utilities
 
 !!! info

docs/src/submodules/Utilities/reference.md

@@ -47,6 +47,12 @@ Utilities.state
 Utilities.mode
 ```
 
+## Printing
+
+```@docs
+Utilities.latex_formulation
+```
+
 ## Copy utilities
 
 The following utilities can be used to implement [`copy_to`](@ref). See

src/Utilities/Utilities.jl

@@ -64,6 +64,7 @@ include("parser.jl")
 include("mockoptimizer.jl")
 include("cachingoptimizer.jl")
 include("universalfallback.jl")
+include("print.jl")
 
 include("lazy_iterators.jl")