Merge pull request #95 from JuliaDiffEq/hg/rm/const

Remove Constant export and @const

Author: ChrisRackauckas

src/variables.jl

@@ -1,3 +1,6 @@
+export Variable, Unknown, Parameter, @Unknown, @Param
+
+
 struct Variable <: Expression
     name::Symbol
     subtype::Symbol
@@ -7,8 +10,6 @@ end
 Parameter(name; dependents = Variable[]) = Variable(name, :Parameter, dependents)
 Unknown(name; dependents = Variable[]) = Variable(name, :Unknown, dependents)
 
-export Variable, Unknown, Parameter, Constant, @Unknown, @Param, @Const
-
 
 struct Constant <: Expression
     value::Number
@@ -76,23 +77,3 @@ end
 macro Param(xs...)
     esc(_parse_vars(:Param, Parameter, xs))
 end
-
-function _const_assign(x)
-    ex = Expr(:block)
-    lhss = Symbol[]
-    x = flatten_expr!(x)
-    for eq in x
-        @assert eq isa Expr && eq.head == :(=) "@Const expects a tuple of assignments!\nE.g. `@Const D=t W=g`"
-        lhs = eq.args[1]
-        push!(lhss, lhs)
-        rhs = eq.args[2]
-        expr = :($lhs = Constant($rhs))
-        push!(ex.args,  expr)
-    end
-    push!(ex.args, Expr(:tuple, lhss...))
-    ex
-end
-
-macro Const(x...)
-    esc(_const_assign(x))
-end

test/basic_variables_and_operations.jl

@@ -4,7 +4,6 @@ using Test
 @Param t σ ρ β
 @Unknown x(t) y(t) z(t)
 @Deriv D'~t
-@Const c=0
 
 # Default values
 p = Parameter(:p)
@@ -15,4 +14,4 @@ D(x)
 D(x) ~ -σ*(y-x)
 D(y) ~ x*(ρ-z)-sin(y)
 
-@test D(t) == Constant(1)
+@test D(t) == 1

test/derivatives.jl

@@ -38,7 +38,7 @@ jac = ModelingToolkit.calculate_jacobian(sys)
 
 # Variable dependence checking in differentiation
 @Unknown a(t) b(a)
-@test D(b) ≠ Constant(0)
+@test D(b) ≠ 0
 
 @test expand_derivatives(D(x * y)) == simplify_constants(y*D(x) + x*D(y))
 @test_broken expand_derivatives(D(x * y)) == simplify_constants(D(x)*y + x*D(y))

test/simplify.jl

@@ -5,7 +5,7 @@ using Test
 @Unknown x(t) y(t) z(t)
 
 null_op = 0*t
-@test simplify_constants(null_op) == Constant(0)
+@test simplify_constants(null_op) == 0
 
 one_op = 1*t
 @test simplify_constants(one_op) == t

test/system_construction.jl

@@ -5,7 +5,6 @@ using Test
 @Param t σ ρ β
 @Unknown x(t) y(t) z(t)
 @Deriv D'~t
-@Const c=0
 
 # Define a differential equation
 eqs = [D(x) ~ σ*(y-x),

test/variable_parsing.jl

@@ -31,11 +31,3 @@ s1 = Parameter(:s)
 D1 = Differential(t, 2)
 @test D1 == D
 @test convert(Expr, D) == D
-
-@Const c=0 v=2
-c1 = Constant(0)
-v1 = Constant(2)
-@test c1 == c
-@test v1 == v
-@test convert(Expr, c) == 0
-@test convert(Expr, v) == 2