Merge pull request #1798 from ValentinKaisermayer/vk-discrete-var-metadata

Adds binary and integer options to variable metadata

Author: YingboMa

src/ModelingToolkit.jl

@@ -176,7 +176,8 @@ export NonlinearSystem, OptimizationSystem
 export alias_elimination, flatten
 export connect, @connector, Connection, Flow, Stream, instream
 export isinput, isoutput, getbounds, hasbounds, isdisturbance, istunable, getdist, hasdist,
-       tunable_parameters, isirreducible, getdescription, hasdescription
+       tunable_parameters, isirreducible, getdescription, hasdescription, isbinaryvar,
+       isintegervar
 export ode_order_lowering, dae_order_lowering, liouville_transform
 export PDESystem
 export Differential, expand_derivatives, @derivatives

src/variables.jl

@@ -289,3 +289,37 @@ end
 function hasdescription(x)
     getdescription(x) != ""
 end
+
+## binary variables =================================================================
+struct VariableBinary end
+Symbolics.option_to_metadata_type(::Val{:binary}) = VariableBinary
+
+isbinaryvar(x::Num) = isbinaryvar(Symbolics.unwrap(x))
+
+"""
+    isbinaryvar(x)
+
+Determine if a variable is binary.
+"""
+function isbinaryvar(x)
+    p = Symbolics.getparent(x, nothing)
+    p === nothing || (x = p)
+    return Symbolics.getmetadata(x, VariableBinary, false)
+end
+
+## integer variables =================================================================
+struct VariableInteger end
+Symbolics.option_to_metadata_type(::Val{:integer}) = VariableInteger
+
+isintegervar(x::Num) = isintegervar(Symbolics.unwrap(x))
+
+"""
+    isintegervar(x)
+
+Determine if a variable is integer.
+"""
+function isintegervar(x)
+    p = Symbolics.getparent(x, nothing)
+    p === nothing || (x = p)
+    return Symbolics.getmetadata(x, VariableInteger, false)
+end

test/test_variable_metadata.jl

@@ -82,3 +82,19 @@ sp = Set(p)
 @named sys = ODESystem([u ~ p], t)
 
 @test_nowarn show(stdout, "text/plain", sys)
+
+@testset "binary" begin
+    @parameters t
+    @variables u(t) [binary = true]
+    @parameters p [binary = true]
+    @test isbinaryvar(u)
+    @test isbinaryvar(p)
+end
+
+@testset "integer" begin
+    @parameters t
+    @variables u(t) [integer = true]
+    @parameters p [integer = true]
+    @test isintegervar(u)
+    @test isintegervar(p)
+end