Fix writing integer variables with float bounds (#68)

Author: odow

Project.toml

@@ -1,7 +1,7 @@
 name = "MiniZinc"
 uuid = "a7f392d2-6c35-496e-b8cc-0974fbfcbf91"
 authors = ["odow <[email protected]>"]
-version = "0.3.8"
+version = "0.3.9"
 
 [deps]
 Chuffed_jll = "77125aae-c893-5498-99e3-e30470bfa328"

README.md

@@ -11,6 +11,12 @@ interact with `libminizinc`.
 This wrapper is maintained by the JuMP community and is not part of the MiniZinc
 project.
 
+## Getting help
+
+If you need help, please ask a question on the [JuMP community forum](https://jump.dev/forum).
+
+If you have a reproducible example of a bug, please [open a GitHub issue](https://github.com/jump-dev/MiniZinc.jl/issues/new).
+
 ## License
 
 `MiniZinc.jl` is licensed under the [MIT License](https://github.com/jump-dev/MiniZinc.jl/blob/master/LICENSE.md).

src/write.jl

@@ -35,7 +35,12 @@ function _variable_info(model::Model{T}, x) where {T}
         lb, ub = set.lower, set.upper
     end
     if is_bool || is_int
-        lb, ub = ceil(Int, lb), floor(Int, ub)
+        if isfinite(lb) && !isinteger(lb)
+            lb = ceil(Int, lb)
+        end
+        if isfinite(ub) && !isinteger(ub)
+            ub = floor(Int, ub)
+        end
     end
     return (name = name, lb = lb, ub = ub, is_int = is_int, is_bool = is_bool)
 end

test/runtests.jl

@@ -1503,6 +1503,39 @@ function test_run_failure()
     return
 end
 
+function test_highs_free_binary()
+    model = MOI.Utilities.Model{Float64}()
+    x, _ = MOI.add_constrained_variable(model, MOI.ZeroOne())
+    solver = MiniZinc.Optimizer{Float64}("highs")
+    index_map, _ = MOI.optimize!(solver, model)
+    @test MOI.get(solver, MOI.TerminationStatus()) == MOI.OPTIMAL
+    return
+end
+
+function test_highs_int_frac_lb()
+    model = MOI.Utilities.Model{Float64}()
+    x, _ = MOI.add_constrained_variable(model, MOI.Integer())
+    MOI.add_constraint(model, x, MOI.GreaterThan(0.5))
+    MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
+    MOI.set(model, MOI.ObjectiveFunction{typeof(x)}(), x)
+    solver = MiniZinc.Optimizer{Float64}("highs")
+    index_map, _ = MOI.optimize!(solver, model)
+    @test MOI.get(solver, MOI.VariablePrimal(), index_map[x]) ≈ 1.0
+    return
+end
+
+function test_highs_int_frac_ub()
+    model = MOI.Utilities.Model{Float64}()
+    x, _ = MOI.add_constrained_variable(model, MOI.Integer())
+    MOI.add_constraint(model, x, MOI.LessThan(2.5))
+    MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+    MOI.set(model, MOI.ObjectiveFunction{typeof(x)}(), x)
+    solver = MiniZinc.Optimizer{Float64}("highs")
+    index_map, _ = MOI.optimize!(solver, model)
+    @test MOI.get(solver, MOI.VariablePrimal(), index_map[x]) ≈ 2.0
+    return
+end
+
 end
 
 TestMiniZinc.runtests()