adamc@2: (* Copyright (c) 2008, Adam Chlipala
adamc@2:  * All rights reserved.
adamc@2:  *
adamc@2:  * Redistribution and use in source and binary forms, with or without
adamc@2:  * modification, are permitted provided that the following conditions are met:
adamc@2:  *
adamc@2:  * - Redistributions of source code must retain the above copyright notice,
adamc@2:  *   this list of conditions and the following disclaimer.
adamc@2:  * - Redistributions in binary form must reproduce the above copyright notice,
adamc@2:  *   this list of conditions and the following disclaimer in the documentation
adamc@2:  *   and/or other materials provided with the distribution.
adamc@2:  * - The names of contributors may not be used to endorse or promote products
adamc@2:  *   derived from this software without specific prior written permission.
adamc@2:  *
adamc@2:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@2:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@2:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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adamc@2:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
adamc@2:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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adamc@2:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@2:  * POSSIBILITY OF SUCH DAMAGE.
adamc@2:  *)
adamc@2: 
adamc@2: structure ElabEnv :> ELAB_ENV = struct
adamc@2: 
adamc@2: open Elab
adamc@2: 
adamc@2: structure IM = IntBinaryMap
adamc@2: structure SM = BinaryMapFn(struct
adamc@2:                            type ord_key = string
adamc@2:                            val compare = String.compare
adamc@2:                            end)
adamc@2: 
adamc@2: exception UnboundRel of int
adamc@2: exception UnboundNamed of int
adamc@2: 
adamc@2: datatype var' =
adamc@2:          CRel' of int * kind
adamc@2:        | CNamed' of int * kind
adamc@2: 
adamc@2: datatype var =
adamc@2:          CNotBound
adamc@2:        | CRel of int * kind
adamc@2:        | CNamed of int * kind
adamc@2: 
adamc@2: type env = {
adamc@2:      renameC : var' SM.map,
adamc@2:      relC : (string * kind) list,
adamc@2:      namedC : (string * kind) IM.map
adamc@2: }
adamc@2: 
adamc@2: val namedCounter = ref 0
adamc@2: 
adamc@2: val empty = {
adamc@2:     renameC = SM.empty,
adamc@2:     relC = [],
adamc@2:     namedC = IM.empty
adamc@2: }
adamc@2: 
adamc@2: fun pushCRel (env : env) x k =
adamc@2:     let
adamc@2:         val renameC = SM.map (fn CRel' (n, k) => CRel' (n+1, k)
adamc@2:                                | x => x) (#renameC env)
adamc@2:     in
adamc@2:         {renameC = SM.insert (renameC, x, CRel' (0, k)),
adamc@2:          relC = (x, k) :: #relC env,
adamc@2:          namedC = #namedC env}
adamc@2:     end
adamc@2: 
adamc@2: fun lookupCRel (env : env) n =
adamc@2:     (List.nth (#relC env, n))
adamc@2:     handle Subscript => raise UnboundRel n
adamc@2: 
adamc@2: fun pushCNamed (env : env) x k =
adamc@2:     let
adamc@2:         val n = !namedCounter
adamc@2:     in
adamc@2:         namedCounter := n + 1;
adamc@2:         ({renameC = SM.insert (#renameC env, x, CNamed' (n, k)),
adamc@2:           relC = #relC env,
adamc@2:           namedC = IM.insert (#namedC env, n, (x, k))},
adamc@2:          n)
adamc@2:     end
adamc@2: 
adamc@2: fun lookupCNamed (env : env) n =
adamc@2:     case IM.find (#namedC env, n) of
adamc@2:         NONE => raise UnboundNamed n
adamc@2:       | SOME x => x
adamc@2: 
adamc@2: fun lookupC (env : env) x =
adamc@2:     case SM.find (#renameC env, x) of
adamc@2:         NONE => CNotBound
adamc@2:       | SOME (CRel' x) => CRel x
adamc@2:       | SOME (CNamed' x) => CNamed x
adamc@2: 
adamc@2: end