change to implicit () + (..) for uncalled

Author: ChrisRackauckas

README.md

@@ -166,14 +166,16 @@ including and excluding empty parentheses. When in call format, variables are
 aliased to the given call, allowing implicit use of dependents for convenience.
 
 ```julia
-@dependent_parameters t() α() σ
-@variables w x(t) y() z(t, α, x)
+@parameters t α σ(..)
+@variables w(..) x(t) y() z(t, α, x)
 
 expr = x + y^α + σ(3) * (z - t) - w(t - 1)
 ```
 
-`@parameters` is a simplified tool for defining constant parameters, meaning
-`@parameters t`  is the same as `@dependent_parameters t()`
+Note that `@parameters` and `@variables` implicitly add `()` to values that
+are not given a call. The former specifies the values as known, while the
+latter specifies it as unknown. `(..)` signifies that the value should be
+left uncalled.
 
 ### Constants
 

src/variables.jl

@@ -29,7 +29,7 @@ Base.convert(::Type{Expr}, c::Constant) = c.value
 
 
 # Build variables more easily
-function _parse_vars(macroname, known, x, add_call = true)
+function _parse_vars(macroname, known, x)
     ex = Expr(:block)
     var_names = Symbol[]
     # if parsing things in the form of
@@ -47,14 +47,15 @@ function _parse_vars(macroname, known, x, add_call = true)
 
         if iscall
             var_name = _var.args[1]
-            expr = :($var_name = $Variable($(Meta.quot(var_name)); known = $known)($(_var.args[2:end]...)))
-        else
-            var_name = _var
-            if add_call
-                expr = :($var_name = $Variable($(Meta.quot(var_name)); known = $known)())
-            else
+            if _var.args[end] == :..
                 expr = :($var_name = $Variable($(Meta.quot(var_name)); known = $known))
+            else
+                expr = :($var_name = $Variable($(Meta.quot(var_name)); known = $known)($(_var.args[2:end]...)))
             end
+        else
+            # Implicit 0-args call
+            var_name = _var
+            expr = :($var_name = $Variable($(Meta.quot(var_name)); known = $known)())
         end
 
         push!(var_names, var_name)
@@ -69,6 +70,3 @@ end
 macro parameters(xs...)
     esc(_parse_vars(:parameters, true, xs))
 end
-macro dependent_parameters(xs...)
-    esc(_parse_vars(:parameters, true, xs, false))
-end

test/system_construction.jl

@@ -60,7 +60,7 @@ fwt(FW, u, p, 0.2, 0.1)
         du ≈ [11, -3, -7]
     end
 
-    @dependent_parameters σ
+    @parameters σ(..)
     eqs = [D(x) ~ σ(t-1)*(y-x),
            D(y) ~ x*(ρ-z)-y,
            D(z) ~ x*y - β*z]

test/variable_parsing.jl

@@ -15,7 +15,7 @@ z1 = Variable(:z)(t)
     t
     s
 end
-@dependent_parameters σ
+@parameters σ(..)
 
 t1 = Variable(:t; known = true)()
 s1 = Variable(:s; known = true)()