added index types

docs/make.jl

@@ -7,6 +7,8 @@ const _PAGES = [
     "Home" => "index.md",
     "API Reference" => [
         "reference/domains.md",
+        "reference/algebraic.md",
+        "reference/differentiable.md",
     ],
 ]
 

docs/src/reference/algebraic.md

@@ -0,0 +1,9 @@
+```@meta
+CurrentModule = DynOptInterface
+```
+
+# Algebraic Variables
+
+```@docs
+AlgebraicIndex
+```

docs/src/reference/differentiable.md

@@ -0,0 +1,9 @@
+```@meta
+CurrentModule = DynOptInterface
+```
+
+# Differentiable Variables
+
+```@docs
+DifferentiableIndex
+```

docs/src/reference/domains.md

@@ -5,11 +5,5 @@ CurrentModule = DynOptInterface
 # Domains
 
 ```@docs
-AbstractDomain
 DomainIndex
-supports_domain
-UnsupportedDomain
-AddDomainNotAllowed
-add_domain
-Interval
 ```

src/DynOptInterface.jl

@@ -2,6 +2,7 @@ module DynOptInterface
 
 import MathOptInterface as MOI
 
-include("domains.jl")
+include("indices.jl")
+
 
 end

src/functions.jl

@@ -0,0 +1,16 @@
+"""
+    ScalarNonlinearDOFunction(head::Sumbol, args::Vector{Any})
+
+A scalar-valued nonlinear DO function `head(args...)`. Each argument must be one of the following:
+
+* A constant value of type `T<:Real`
+* An `MOI.VariableIndex`
+* An `MOI.ScalarNonlinearFunction`
+* A [`DomainIndex`](@ref)
+* An [`AlgebraicIndex`](@ref)
+* A [`DifferentiableIndex`](@ref)
+"""
+struct ScalarNonlinearDOFunction
+    head::Symbol
+    args::Vector{Any}
+end

src/indices.jl

@@ -0,0 +1,28 @@
+"""
+    DomainIndex
+
+A type-safe wrapper for `Int64` for use in referencing domains.
+"""
+struct DomainIndex
+    value::Int64
+end
+
+"""
+    AlgebraicIndex
+
+A type-safe wrapper for `Int64` for use in referencing algebraic variables.
+"""
+struct AlgebraicIndex
+    value::Int64
+    domain::DomainIndex
+end
+
+"""
+    DifferentiableIndex
+
+A type-safe wrapper for `Int64` for use in referencing differentiable variables.
+"""
+struct DifferentiableIndex
+    value::Int64
+    domain::DomainIndex
+end