Fix a subtle bug in adding parameters to local procedure envs

I couldn't use e[p[1]] = r[1] because that invokes environment's __newindex
metamethod, which is equivalent to `set!' -- that is, it mutates the existing
binding from the closest enclosing environment

1 files changed, 2 insertions, 3 deletions

@@ -299,8 +299,7 @@ function m.procedure (params, body, env, eval)
                                         end
                                         -- (lambda x ..) or (lambda (x . y) ..)
                                         if type.isp(p, "symbol") then
-                                                e[p] = r
-                                                return e
+                                                return rawset(e, p, r)
                                         end
                                         if p[1] == nil then
                                                 error("too many arguments",
@@ -311,7 +310,7 @@ function m.procedure (params, body, env, eval)
                                                         rlen, #self.params)
                                         end
                                         -- bind car(p) to car(r)
-                                        e[p[1]] = r[1]
+                                        rawset(e, p[1], r[1])
                                         -- recurse
                                         return doargs(p[2], r[2], e)
                                 end