Merge pull request #113 from JuliaDiffEq/myb/var

Parse an expression of a tuple

Author: YingboMa

src/differentials.jl

@@ -61,9 +61,10 @@ _repeat_apply(f, n) = n == 1 ? f : f ∘ _repeat_apply(f, n-1)
 function _differential_macro(x)
     ex = Expr(:block)
     lhss = Symbol[]
+    x = x isa Tuple && first(x).head == :tuple ? first(x).args : x # tuple handling
     x = flatten_expr!(x)
     for di in x
-        @assert di isa Expr && di.args[1] == :~ "@derivatives expects a form that looks like `@derivatives D''~t E'~t`"
+        @assert di isa Expr && di.args[1] == :~ "@derivatives expects a form that looks like `@derivatives D''~t E'~t` or `@derivatives (D''~t), (E'~t)`"
         lhs = di.args[2]
         rhs = di.args[3]
         order, lhs = count_order(lhs)

src/variables.jl

@@ -49,11 +49,12 @@ function _parse_vars(macroname, known, x)
     #     y
     #     z
     # end
+    x = x isa Tuple && first(x) isa Expr && first(x).head == :tuple ? first(x).args : x # tuple handling
     x = flatten_expr!(x)
     for _var in x
         iscall = isa(_var, Expr) && _var.head == :call
         issym    = _var isa Symbol
-        @assert iscall || issym "@$macroname expects a tuple of expressions (`@$macroname x y z(t)`)"
+        @assert iscall || issym "@$macroname expects a tuple of expressions or an expression of a tuple (`@$macroname x y z(t)` or `@$macroname x, y, z(t)`)"
 
         if iscall
             dependents = :(Variable[$(_var.args[2:end]...)])
@@ -71,8 +72,8 @@ function _parse_vars(macroname, known, x)
     return ex
 end
 macro variables(xs...)
-    esc(_parse_vars(:Variable, false, xs))
+    esc(_parse_vars(:variables, false, xs))
 end
 macro parameters(xs...)
-    esc(_parse_vars(:Param, true, xs))
+    esc(_parse_vars(:parameters, true, xs))
 end

test/derivatives.jl

@@ -6,6 +6,8 @@ using Test
 @variables x(t) y(t) z(t)
 @derivatives D'~t D2''~t
 
+@test @macroexpand(@derivatives D'~t D2''~t) == @macroexpand(@derivatives (D'~t), (D2''~t))
+
 @test isequal(expand_derivatives(D(t)), 1)
 @test isequal(expand_derivatives(D(D(t))), 0)
 

test/variable_parsing.jl

@@ -2,9 +2,8 @@ using ModelingToolkit
 using Test
 
 @parameters t
-@variables x(t)
-@variables y(t)
-@variables z(t)
+@variables x(t) y(t) # test multi-arg
+@variables z(t) # test single-arg
 x1 = Variable(:x, [t])
 y1 = Variable(:y, [t])
 z1 = Variable(:z, [t])
@@ -33,3 +32,6 @@ D1 = Differential(t)
 @test convert(Expr, D) == D
 
 @test isequal(x ≤ y + 1, (x < y + 1) | (x == y + 1))
+
+@test @macroexpand(@parameters x, y, z(t)) == @macroexpand(@parameters x y z(t))
+@test @macroexpand(@variables x, y, z(t)) == @macroexpand(@variables x y z(t))