diff options
Diffstat (limited to 'toplevel')
| -rw-r--r-- | toplevel/classes.ml | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/toplevel/classes.ml b/toplevel/classes.ml index 7ff942253a..081d182921 100644 --- a/toplevel/classes.ml +++ b/toplevel/classes.ml @@ -185,9 +185,17 @@ let new_instance ?(global=false) ctx (instid, bk, cl) props ?(generalize=true) end else begin - let props = match props with CRecord (loc, _, fs) -> fs | _ -> assert false in - if List.length props > List.length k.cl_props then - mismatched_props env' (List.map snd props) k.cl_props; + let props = + match props with + | CRecord (loc, _, fs) -> + if List.length fs > List.length k.cl_props then + mismatched_props env' (List.map snd fs) k.cl_props; + fs + | _ -> + if List.length k.cl_props <> 1 then + errorlabstrm "new_instance" (Pp.str "Expected a definition for the instance body") + else [(dummy_loc, Nameops.out_name (pi1 (List.hd k.cl_props))), props] + in let subst = match k.cl_props with | [(na,b,ty)] -> |