Remove interval and NonNegative operators (#28)

* remove `interval` and `NonNegative`, as these are better expressed with inequalities

* picky formatter lulz

src/json_to_moi.jl

@@ -51,27 +51,14 @@ function add_cons!(
         _check_v_type(v)
         MOI.add_constraint(model, v, MOI.ZeroOne())
     elseif head == "Float"
-    elseif head == "Nonneg"
-        v = json_to_snf(a[2], vars_map)
-        _check_v_type(v)
-        MOI.add_constraint(model, v, MOI.GreaterThan(zero(T)))
+        # no-op
     elseif head == "PosNegOne"
         v = json_to_snf(a[2], vars_map)
         _check_v_type(v)
         # TODO only for MiniZinc
         MOI.add_constraint(model, v, MOI.Integer())
         f = MOI.ScalarNonlinearFunction(:abs, Any[v])
         MOI.add_constraint(model, f, MOI.EqualTo(1))
-    elseif head == "interval"
-        if length(a) != 4
-            throw(Error(InvalidModel, "The `interval` constraint expects three arguments."))
-        end
-        v = json_to_snf(a[4], vars_map)
-        _check_v_type(v)
-        if !(a[2] isa Number && a[3] isa Number)
-            throw(Error(InvalidModel, "The `interval` constraint expects number bounds."))
-        end
-        MOI.add_constraint(model, v, MOI.Interval{T}(T(a[2]), T(a[3])))
     elseif head == "range"
         if length(a) != 5
             throw(Error(InvalidModel, "The `range` constraint expects four arguments."))

test/all_tests.jl

@@ -61,7 +61,6 @@ end
     # names of JSON files in inputs/ and outputs/ folders
     json_names = [
         "feas_range",
-        "min_interval",
         "tiny_min",
         "tiny_feas",
         "tiny_infeas",
@@ -194,10 +193,7 @@ end
         ),
     )
 
-    result = solve(
-        tiny_min,
-        HiGHS.Optimizer()
-    )
+    result = solve(tiny_min, HiGHS.Optimizer())
 
     @test result["termination_status"] == "OPTIMIZE_NOT_CALLED"
     @test result["model_string"] isa String
@@ -222,11 +218,7 @@ end
         ),
     )
 
-    result = solve(
-        tiny_min,
-        HiGHS.Optimizer(),
-        Dict{Symbol,Any}(:print_only => true)
-    )
+    result = solve(tiny_min, HiGHS.Optimizer(), Dict{Symbol,Any}(:print_only => true))
 
     @test result["termination_status"] == "OPTIMIZE_NOT_CALLED"
     @test result["model_string"] isa String
@@ -272,8 +264,6 @@ end
         ("incorrect_range_num_params", "InvalidModel"),
         # range: step not one
         ("incorrect_range_step_not_1", "InvalidModel"),
-        # interval: wrong number of args
-        ("incorrect_interval_num_params", "InvalidModel"),
         # relational application constraint malformed
         ("in_con_malformed", "InvalidModel"),
         # unsupported objective function type

test/inputs/abs_gap_out_of_range.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HIGHS", "absolute_gap_tolerance":-0.1}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HIGHS", "absolute_gap_tolerance":-0.1}}

test/inputs/cons_false.json

@@ -1 +1 @@
-{"version":"0.1","sense":"feas","variables":["x"],"constraints":[["==",1,0],["Nonneg","x"]],"objectives":[],"options":{"solver":"highs"}}
+{"version":"0.1","sense":"feas","variables":["x"],"constraints":[["==",1,0],[">=","x",0]],"objectives":[],"options":{"solver":"highs"}}

test/inputs/cons_true.json

@@ -1 +1 @@
-{"version":"0.1","sense":"feas","variables":["x_1","x_2"],"constraints":[["==",0,0],["Nonneg","x_1"],["Nonneg","x_2"]],"objectives":[],"options":{"solver":"highs"}}
+{"version":"0.1","sense":"feas","variables":["x_1","x_2"],"constraints":[["==",0,0],[">=","x_1",0],[">=","x_2",0]],"objectives":[],"options":{"solver":"highs"}}

test/inputs/empty_arr_con.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[[">=","x",1.5],[],["Nonneg","x"],["Nonneg","y"]],"objectives":[["+","x","y"]],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[[">=","x",1.5],[],[">=","x",0],[">=","y",0]],"objectives":[["+","x","y"]],"options":{"solver":"HiGHS"}}

test/inputs/min_constant.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x"],"constraints":[["==","x",1],["Int","x"]],"objectives":[1.5],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x"],"constraints":[["==","x",1],["Bin","x"]],"objectives":[1.5],"options":{"solver":"HiGHS"}}

test/inputs/rel_gap_out_of_range.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HIGHS", "relative_gap_tolerance":1.1}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HIGHS", "relative_gap_tolerance":1.1}}

test/inputs/simple_lp.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Bin","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}

test/inputs/unsupported_con_sign.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["!=",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["!=",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}

test/inputs/unsupported_con_type.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["*","x",["*","x","y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["*","x",["*","x","y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Int","y"]],"objectives":[["+",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}

test/inputs/unsupported_obj_type.json

@@ -1 +1 @@
-{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],["Nonneg","x"]],["Int","y"]],"objectives":[["/",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}
+{"version":"0.1","sense":"min","variables":["x","y"],"constraints":[["and",["==",["+","x",["*",3,"y"]],1],[">=",["+","x","y"],1]],["and",["Int","x"],[">=","x",0]],["Int","y"]],"objectives":[["/",["*",2,"x"],"y"]],"options":{"solver":"HiGHS"}}