Convert :if blocks to ifelse calls

Author: HarrisonGrodin

src/utils.jl

@@ -2,6 +2,7 @@ using MacroTools
 
 
 function Base.convert(::Type{Expression}, ex::Expr)
+    ex.head === :if && (ex = Expr(:call, ifelse, ex.args...))
     ex.head === :call || throw(ArgumentError("internal representation does not support non-call Expr"))
 
     op = eval(ex.args[1])  # HACK

test/variable_parsing.jl

@@ -32,3 +32,5 @@ D1 = Differential(t)
 
 @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))
+
+convert(Expression, :($x == 0 ? $y : $x))