let reserve1 space key =
if Kset.mem key space.reserved then
Wp_parameters.fatal "Already reserved name '%s'" key ;
space.reserved <- Kset.add key space.reserved ;
try
let a = Hashtbl.find space.alloc key in
if a.based then Wp_parameters.fatal
"Reserved name '%s' clashes with named identifier" key
with Not_found -> ()