found typo

Author: a

src/expr.jl

@@ -10,6 +10,6 @@ children(e::Expr) = e.args
 operation(e::Expr) = iscall(e) ? first(children(e)) : error("operation called on a non-function call expression")
 arguments(e::Expr) = iscall(e) ? @view(e.args[2:end]) : error("arguments called on a non-function call expression")
 
-function maketerm(::Type{Expr}, head, args, symtype=nothing, metadata=nothing)
+function maketerm(::Type{Expr}, head, args, type=nothing, metadata=nothing)
     Expr(head, args...)
 end