add some basic domains

Author: ChrisRackauckas

src/ModelingToolkit.jl

@@ -8,6 +8,7 @@ abstract type Expression <: Number end
 abstract type AbstractOperation <: Expression end
 abstract type AbstractOperator <: Expression end
 abstract type AbstractSystem end
+abstract type AbstractDomain end
 
 include("variables.jl")
 
@@ -23,6 +24,7 @@ include("systems/diffeqs/diffeqsystem.jl")
 include("systems/diffeqs/first_order_transform.jl")
 include("systems/nonlinear/nonlinear_system.jl")
 include("function_registration.jl")
+include("domains.jl")
 include("simplify.jl")
 include("utils.jl")
 

src/domains.jl

@@ -0,0 +1,18 @@
+Base.ndims(::AbstractDomain) = error("Domain dimension is undefined")
+
+struct DiscreteDomain <: AbstractDomain
+    length::Int
+end
+
+struct Interval{T} <: AbstractDomain
+  start::T
+  stop::T
+end
+
+struct ProductDomain{T} <: AbstractDomain
+    domains::T
+end
+
+Base.:*(x::AbstractDomain...) = ProductDomain((x...))
+
+export DiscreteDomain, Interval, ProductDomain

test/domains.jl

@@ -0,0 +1,7 @@
+using ModelingToolkit
+using Base.Test
+
+d = DiscreteDomain(5) * Interval(0.0,5.0)
+typeof(d) <: ProductDomain
+typeof(d.domains[1]) <: DiscreteDomain
+typeof(d.domains[2]) <: Interval

test/runtests.jl

@@ -4,5 +4,6 @@ using ModelingToolkit, Base.Test
 @testset "Basic Variables and Operations" begin include("basic_variables_and_operations.jl") end
 @testset "Differentiation Test" begin include("derivatives.jl") end
 @testset "Internal Test" begin include("internal.jl") end
+@testset "Domain Test" begin include("domains.jl") end
 @testset "Ambiguity Test" begin include("ambiguity.jl") end
 @testset "System Construction Test" begin include("system_construction.jl") end