formatting - sml-mode for emacs does extremely strange things. Is there an alternative, or an easy elisp fix? -

i'm having lot of trouble getting sml-mode in emacs sanely indent code. example, here block behaving particularly strangely:

    datatype type_node       = param of typaram.t       | longid of longid.t       | offset of field * field list option       | list of type_t list       | fun of type_t list * t list       |       | vproc       | cont of tyarg.t list option       | addr of type_t          , dataconsdef_node              = consdef of bomid.t * type_t option          , field_node              = immutable of int * type_t              | mutable of int * type_t          , fundef_node              = def of attrs.t option * bomid.t * typaram.t list option                       * param.t list option * param.t list option * type_t * exp_t          , varpat_node              = wild              | var of bomid.t * type_t option          , caserule_node              = longrule of longid.t * varpat_t list * exp_t            | literalrule literal.t * exp_t            | defaultrule of varpat_t * exp_t          , tycaserule_node              = tyrule of type_t * exp_t              | default of exp_t          , simpleexp_node              = primop of 'var prim.prim * simpleexp_t list              | allocid of longid.t * simpleexp_t list              | alloctype of type.t * simpleexp_t list              | atindex of int * simpleexp_t * simpleexp_t option              | typecast of type.t * simpleexp_t              | hostvproc              | vpload of int * simpleexp_t              | vpaddr of int * simpleexp_t              | vpstore of int * simpleexp_t * t              | id of longid.t              | lit of literal.t              | mlstring of string          , exp_node              = let of varpat.t list * rhs * t              | of simpleexp.t * t              | fun of fundef.t list * t              | cont of bomid.t * param.t list option * t * t              | if of simpleexp.t * t * t              | case of simpleexp.t * caserule.t list                      | typecase of typaram.t * tycaserule.t list                                  | apply of longid.t * simpleexp.t list option * simpleexp.t list option                                           | throw of longid.t * simpleexp.t list option                                                    | return of simpleexp.t list option   , foo_node           = bar 

apologies huge code dump, content doesn't matter -- extremely inconsistent indentation. attempting define signatures inside of structure foo : sig ... end = struct ... end block worse:

structure attrs : sig               type t               datatype node                 = attributes of string list                                        include wrapped                                        sharing type node' = node                                                                 sharing type obj = t           end 

or:

functor dowrap(type node) : sig             type t = node wrap.t                           include wrapped                           sharing type node' = node                                                    sharing type obj = t         end = struct                             open wrap                             type t = node wrap.t                             type node' = node                             type obj = t                             end 

i'm diehard emacs fan , hate have avoid on project, since it's 1 i'll working on the next few months. however, can't turn code in supervisor. above behavior when select block of text , indent-region.

i've looked @ this answer, solution doesn't apply, since behavior m-c-\ gives me, , huge pain work on code without being able auto-indent whole file.

is there easy fix this? there alternative sml-mode implementations?

presuming using latest version of sml mode gnu elpa, looks have hit corner-case in built-in smie grammar of sml mode breaks down. had similar issues tuareg mode ocaml.

you need downgrade version of sml mode version 4.0 or lower, can obtain http://www.iro.umontreal.ca/~monnier/elisp/. these versions not yet use smie indentation, ad-hoc indentation code. @ least ocaml , tuareg, found old-fashioned approach yield better , more reliable indentation.

you may want report issue maintainer of sml mode, though, mail address can find in header of sml mode, or in footer of aforementioned website.