Merge repository ligo-utils

2019-05-27 11:56:53 +02:00 · 2019-05-27 11:56:53 +02:00 · fd513af745
commit fd513af745
parent 28d3bc8c3f 7c8c6515b8
61 changed files with 4598 additions and 0 deletions
--- a/vendors/ligo-utils/.gitignore
+++ b/vendors/ligo-utils/.gitignore
@ -0,0 +1,6 @@
+_build/*
+*/_build
+.merlin
+*/.merlin
+*.install
+*/*.install
--- a/vendors/ligo-utils/proto-alpha-utils/cast.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/cast.ml
@ -0,0 +1,190 @@
+module Error_monad = X_error_monad
+open Tezos_micheline
+
+let env = Error_monad.force_lwt ~msg:"Cast:init environment" @@ Init_proto_alpha.init_environment ()
+
+open Memory_proto_alpha
+open Alpha_context
+
+exception Expr_from_string
+let expr_of_string str =
+  let (ast, errs) = Michelson_parser.V1.parse_expression ~check:false str in
+  (match errs with
+   | [] -> ()
+   | lst -> (
+       Format.printf "expr_from_string: %a\n" Error_monad.pp_print_error lst;
+       raise Expr_from_string
+     ));
+  ast.expanded
+
+let tl_of_string str =
+  let (ast, errs) = Michelson_parser.V1.parse_toplevel ~check:false str in
+  (match errs with
+   | [] -> ()
+   | lst -> (
+       Format.printf "expr_from_string: %a\n" Error_monad.pp_print_error lst;
+       raise Expr_from_string
+     ));
+  ast.expanded
+
+let lexpr_of_string str =
+  Script.lazy_expr @@ expr_of_string str
+
+let ltl_of_string str =
+  Script.lazy_expr @@ tl_of_string str
+
+let node_of_string str =
+  Micheline.root @@ expr_of_string str
+
+let node_to_string (node:_ Micheline.node) =
+  let stripped = Micheline.strip_locations node in
+  let print_node = Micheline_printer.printable Michelson_v1_primitives.string_of_prim stripped in
+  Micheline_printer.print_expr Format.str_formatter print_node ;
+  Format.flush_str_formatter ()
+
+open Script_ir_translator
+
+let rec mapper (Ex_typed_value (ty, a)) =
+  let open Alpha_environment.Error_monad in
+  let open Script_typed_ir in
+  let open Micheline in
+  match ty, a with
+  | Big_map_t (kt, vt, Some (`Type_annot "toto")), map ->
+    let kt = ty_of_comparable_ty kt in
+    fold_left_s
+      (fun l (k, v) ->
+         match v with
+         | None -> return l
+         | Some v -> (
+             let key = data_to_node (Ex_typed_value (kt, k)) in
+             let value = data_to_node (Ex_typed_value (vt, v)) in
+             return (Prim (-1, Michelson_v1_primitives.D_Elt, [ key ; value ], []) :: l))
+      )
+      []
+      (map_fold (fun k v acc -> (k, v) :: acc) map.diff []) >>=? fun items ->
+    return (Some (Micheline.Seq (-1, String (-1, "...") :: items)))
+  | _ -> return None
+
+and data_to_node (Ex_typed_value (ty, data)) =
+  let tc = env.tezos_context in
+  let node_lwt = Script_ir_translator.unparse_data tc ~mapper Readable ty data in
+  let node = fst @@ Error_monad.force_lwt_alpha ~msg:"data to string" node_lwt in
+  node
+
+let data_to_string ty data =
+  let node = data_to_node (Ex_typed_value (ty, data)) in
+  node_to_string node
+
+open Script_typed_ir
+open Script_interpreter
+type ex_typed_stack =
+    Ex_typed_stack : ('a stack_ty * 'a stack) -> ex_typed_stack
+
+let stack_to_string stack_ty stack =
+  let rec aux acc fst (Ex_typed_stack(stack_ty,stack)) =
+    match (stack_ty, stack) with
+    | Item_t (hd_ty, tl_ty, _), Item (hd, tl) -> (
+        let separator = if not fst then " ; " else "" in
+        let str = data_to_string hd_ty hd in
+        let acc = acc ^ separator ^ str in
+        let new_value = aux acc false (Ex_typed_stack (tl_ty, tl)) in
+        new_value
+      )
+    | _ -> acc in
+  aux "" true @@ Ex_typed_stack(stack_ty, stack)
+
+let ty_to_node ty =
+  let (node, _) = Error_monad.force_lwt_alpha ~msg:"ty to node" @@ Script_ir_translator.unparse_ty env.tezos_context ty in
+  node
+
+type ex_descr =
+    Ex_descr : (_, _) Script_typed_ir.descr -> ex_descr
+
+let descr_to_node x =
+  let open Alpha_context.Script in
+  let open Micheline in
+  let open! Script_typed_ir in
+  let rec f : ex_descr -> Script.node = fun descr ->
+    let prim ?children ?children_nodes p =
+      match (children, children_nodes) with
+      | Some children, None ->
+        Prim (0, p, List.map f children, [])
+      | Some _, Some _ ->
+        raise @@ Failure "descr_to_node: too many parameters"
+      | None, Some children_nodes ->
+        Prim (0, p, children_nodes, [])
+      | None, None ->
+        Prim (0, p, [], [])
+    in
+    let (Ex_descr descr) = descr in
+    match descr.instr with
+    | Dup -> prim I_DUP
+    | Drop -> prim I_DROP
+    | Swap -> prim I_SWAP
+    | Dip c -> prim ~children:[Ex_descr c] I_DIP
+    | Car -> prim I_CAR
+    | Cdr -> prim I_CDR
+    | Cons_pair -> prim I_PAIR
+    | Nop -> prim I_NOP
+    | Seq (a, b) -> Micheline.Seq (0, List.map f [Ex_descr a ; Ex_descr b])
+    | Const v -> (
+        let (Item_t (ty, _, _)) = descr.aft in
+        prim  ~children_nodes:[data_to_node (Ex_typed_value (ty, v))] I_PUSH
+      )
+    | Failwith _ -> prim I_FAILWITH
+    | If (a, b) -> prim ~children:[Ex_descr a ; Ex_descr b] I_IF
+    | Loop c -> prim ~children:[Ex_descr c] I_LOOP
+    | If_left (a, b) -> prim ~children:[Ex_descr a ; Ex_descr b] I_IF_LEFT
+    | Left -> prim I_LEFT
+    | Right -> prim I_RIGHT
+    | Loop_left c -> prim ~children:[Ex_descr c] I_LOOP_LEFT
+    | If_none (a, b) -> prim ~children:[Ex_descr a ; Ex_descr b] I_IF_NONE
+    | Cons_none _ -> prim I_NONE
+    | Cons_some -> prim I_SOME
+    | Nil -> prim I_NIL
+    | Cons_list -> prim I_CONS
+    | If_cons (a, b) -> prim ~children:[Ex_descr a ; Ex_descr b] I_IF_CONS
+    | List_iter _ -> prim I_ITER
+    | Compare _ -> prim I_COMPARE
+    | Int_nat -> prim I_INT
+    | Add_natnat -> prim I_ADD
+    | Add_natint -> prim I_ADD
+    | Add_intnat -> prim I_ADD
+    | Sub_int -> prim I_SUB
+    | Mul_natnat -> prim I_MUL
+    | Ediv_natnat -> prim I_MUL
+    | Map_get -> prim I_GET
+    | Map_update -> prim I_UPDATE
+    | Big_map_get -> prim I_GET
+    | Big_map_update -> prim I_UPDATE
+    | Gt -> prim I_GT
+    | Ge -> prim I_GE
+    | Pack _ -> prim I_PACK
+    | Unpack _ -> prim I_UNPACK
+    | Blake2b -> prim I_BLAKE2B
+    | And -> prim I_AND
+    | Xor -> prim I_XOR
+    | _ -> raise @@ Failure "descr to node" in
+  f @@ Ex_descr x
+
+let rec flatten_node =
+  let open! Micheline in
+  function
+  | Micheline.Seq (a, lst) -> (
+      let aux = function
+        | Prim (loc, p, children, annot) -> [ Prim (loc, p, List.map flatten_node children, annot) ]
+        | Seq (_, lst) -> List.map flatten_node lst
+        | x -> [ x ] in
+      let seqs = List.map aux @@ List.map flatten_node lst in
+      Seq (a, List.concat seqs) )
+  | x -> x
+
+let descr_to_string descr =
+  let node = descr_to_node descr in
+  let node = flatten_node node in
+  node_to_string node
+
+let n_of_int n =
+  match Script_int.is_nat @@ Script_int.of_int n with
+  | None -> raise @@ Failure "n_of_int"
+  | Some n -> n
--- a/vendors/ligo-utils/proto-alpha-utils/dune
+++ b/vendors/ligo-utils/proto-alpha-utils/dune
@ -0,0 +1,12 @@
+(library
+  (name proto_alpha_utils)
+  (public_name proto-alpha-utils)
+  (libraries
+    tezos-error-monad
+    tezos-stdlib-unix
+    tezos-memory-proto-alpha
+    simple-utils
+    tezos-utils
+  )
+ (flags (:standard -open Simple_utils ))
+)
--- a/vendors/ligo-utils/proto-alpha-utils/dune-project
+++ b/vendors/ligo-utils/proto-alpha-utils/dune-project
@ -0,0 +1 @@
+(lang dune 1.6)
--- a/vendors/ligo-utils/proto-alpha-utils/init_proto_alpha.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/init_proto_alpha.ml
@ -0,0 +1,292 @@
+open! Memory_proto_alpha
+module Signature = Tezos_base.TzPervasives.Signature
+module Data_encoding = Alpha_environment.Data_encoding
+module MBytes = Alpha_environment.MBytes
+module Error_monad = X_error_monad
+open Error_monad
+
+
+
+module Context_init = struct
+
+  type account = {
+      pkh : Signature.Public_key_hash.t ;
+      pk :  Signature.Public_key.t ;
+      sk :  Signature.Secret_key.t ;
+    }
+
+  let generate_accounts n : (account * Tez_repr.t) list =
+    let amount = Tez_repr.of_mutez_exn 4_000_000_000_000L in
+    List.map (fun _ ->
+        let (pkh, pk, sk) = Signature.generate_key () in
+        let account = { pkh ; pk ; sk } in
+        account, amount)
+      (List.range n)
+
+  let make_shell
+        ~level ~predecessor ~timestamp ~fitness ~operations_hash =
+    Tezos_base.Block_header.{
+        level ;
+        predecessor ;
+        timestamp ;
+        fitness ;
+        operations_hash ;
+        (* We don't care of the following values, only the shell validates them. *)
+        proto_level = 0 ;
+        validation_passes = 0 ;
+        context = Alpha_environment.Context_hash.zero ;
+    }
+
+  let default_proof_of_work_nonce =
+    MBytes.create Alpha_context.Constants.proof_of_work_nonce_size
+
+  let protocol_param_key = [ "protocol_parameters" ]
+
+  let check_constants_consistency constants =
+    let open Constants_repr in
+    let open Error_monad in
+    let { blocks_per_cycle ; blocks_per_commitment ;
+          blocks_per_roll_snapshot ; _ } = constants in
+    Error_monad.unless (blocks_per_commitment <= blocks_per_cycle)
+      (fun () -> failwith "Inconsistent constants : blocks per commitment must be \
+                           less than blocks per cycle") >>=? fun () ->
+    Error_monad.unless (blocks_per_cycle >= blocks_per_roll_snapshot)
+      (fun () -> failwith "Inconsistent constants : blocks per cycle \
+                           must be superior than blocks per roll snapshot") >>=?
+      return
+
+
+  let initial_context
+        constants
+        header
+        commitments
+        initial_accounts
+        security_deposit_ramp_up_cycles
+        no_reward_cycles
+    =
+    let open Tezos_base.TzPervasives.Error_monad in
+    let bootstrap_accounts =
+      List.map (fun ({ pk ; pkh ; _ }, amount) ->
+          Parameters_repr.{ public_key_hash = pkh ; public_key = Some pk ; amount }
+        ) initial_accounts
+    in
+    let json =
+      Data_encoding.Json.construct
+        Parameters_repr.encoding
+        Parameters_repr.{
+          bootstrap_accounts ;
+          bootstrap_contracts = [] ;
+          commitments ;
+          constants ;
+          security_deposit_ramp_up_cycles ;
+          no_reward_cycles ;
+      }
+    in
+    let proto_params =
+      Data_encoding.Binary.to_bytes_exn Data_encoding.json json
+    in
+    Tezos_protocol_environment_memory.Context.(
+      set empty ["version"] (MBytes.of_string "genesis")
+    ) >>= fun ctxt ->
+    Tezos_protocol_environment_memory.Context.(
+      set ctxt protocol_param_key proto_params
+    ) >>= fun ctxt ->
+    Main.init ctxt header
+    >|= Alpha_environment.wrap_error >>=? fun { context; _ } ->
+    return context
+
+  let genesis
+        ?(preserved_cycles = Constants_repr.default.preserved_cycles)
+        ?(blocks_per_cycle = Constants_repr.default.blocks_per_cycle)
+        ?(blocks_per_commitment = Constants_repr.default.blocks_per_commitment)
+        ?(blocks_per_roll_snapshot = Constants_repr.default.blocks_per_roll_snapshot)
+        ?(blocks_per_voting_period = Constants_repr.default.blocks_per_voting_period)
+        ?(time_between_blocks = Constants_repr.default.time_between_blocks)
+        ?(endorsers_per_block = Constants_repr.default.endorsers_per_block)
+        ?(hard_gas_limit_per_operation = Constants_repr.default.hard_gas_limit_per_operation)
+        ?(hard_gas_limit_per_block = Constants_repr.default.hard_gas_limit_per_block)
+        ?(proof_of_work_threshold = Int64.(neg one))
+        ?(tokens_per_roll = Constants_repr.default.tokens_per_roll)
+        ?(michelson_maximum_type_size = Constants_repr.default.michelson_maximum_type_size)
+        ?(seed_nonce_revelation_tip = Constants_repr.default.seed_nonce_revelation_tip)
+        ?(origination_size = Constants_repr.default.origination_size)
+        ?(block_security_deposit = Constants_repr.default.block_security_deposit)
+        ?(endorsement_security_deposit = Constants_repr.default.endorsement_security_deposit)
+        ?(block_reward = Constants_repr.default.block_reward)
+        ?(endorsement_reward = Constants_repr.default.endorsement_reward)
+        ?(cost_per_byte = Constants_repr.default.cost_per_byte)
+        ?(hard_storage_limit_per_operation = Constants_repr.default.hard_storage_limit_per_operation)
+        ?(commitments = [])
+        ?(security_deposit_ramp_up_cycles = None)
+        ?(no_reward_cycles = None)
+        (initial_accounts : (account * Tez_repr.t) list)
+    =
+    if initial_accounts = [] then
+      Pervasives.failwith "Must have one account with a roll to bake";
+
+    (* Check there is at least one roll *)
+    let open Tezos_base.TzPervasives.Error_monad in
+    begin try
+        let (>>?=) x y = match x with
+          | Ok(a) -> y a
+          | Error(b) -> fail @@ List.hd b in
+        fold_left_s (fun acc (_, amount) ->
+            Alpha_environment.wrap_error @@
+              Tez_repr.(+?) acc amount >>?= fun acc ->
+                                            if acc >= tokens_per_roll then
+                                              raise Exit
+                                            else return acc
+          ) Tez_repr.zero initial_accounts >>=? fun _ ->
+        failwith "Insufficient tokens in initial accounts to create one roll"
+      with Exit -> return ()
+    end >>=? fun () ->
+
+    let constants : Constants_repr.parametric = {
+        preserved_cycles ;
+        blocks_per_cycle ;
+        blocks_per_commitment ;
+        blocks_per_roll_snapshot ;
+        blocks_per_voting_period ;
+        time_between_blocks ;
+        endorsers_per_block ;
+        hard_gas_limit_per_operation ;
+        hard_gas_limit_per_block ;
+        proof_of_work_threshold ;
+        tokens_per_roll ;
+        michelson_maximum_type_size ;
+        seed_nonce_revelation_tip ;
+        origination_size ;
+        block_security_deposit ;
+        endorsement_security_deposit ;
+        block_reward ;
+        endorsement_reward ;
+        cost_per_byte ;
+        hard_storage_limit_per_operation ;
+      } in
+    check_constants_consistency constants >>=? fun () ->
+
+    let hash =
+      Alpha_environment.Block_hash.of_b58check_exn "BLockGenesisGenesisGenesisGenesisGenesisCCCCCeZiLHU"
+    in
+    let shell = make_shell
+                  ~level:0l
+                  ~predecessor:hash
+                  ~timestamp:Tezos_base.TzPervasives.Time.epoch
+                  ~fitness: (Fitness_repr.from_int64 0L)
+                  ~operations_hash: Alpha_environment.Operation_list_list_hash.zero in
+    initial_context
+      constants
+      shell
+      commitments
+      initial_accounts
+      security_deposit_ramp_up_cycles
+      no_reward_cycles
+    >>=? fun context ->
+    return (context, shell, hash)
+
+  let init
+        ?(slow=false)
+        ?preserved_cycles
+        ?endorsers_per_block
+        ?commitments
+        n =
+    let open Error_monad in
+    let accounts = generate_accounts n in
+    let contracts = List.map (fun (a, _) ->
+                        Alpha_context.Contract.implicit_contract (a.pkh)) accounts in
+    begin
+      if slow then
+        genesis
+          ?preserved_cycles
+          ?endorsers_per_block
+          ?commitments
+          accounts
+      else
+        genesis
+          ?preserved_cycles
+          ~blocks_per_cycle:32l
+          ~blocks_per_commitment:4l
+          ~blocks_per_roll_snapshot:8l
+          ~blocks_per_voting_period:(Int32.mul 32l 8l)
+          ?endorsers_per_block
+          ?commitments
+          accounts
+    end >>=? fun ctxt ->
+    return (ctxt, accounts, contracts)
+
+  let contents
+        ?(proof_of_work_nonce = default_proof_of_work_nonce)
+        ?(priority = 0) ?seed_nonce_hash () =
+    Alpha_context.Block_header.({
+        priority ;
+        proof_of_work_nonce ;
+        seed_nonce_hash ;
+      })
+
+
+  let begin_construction ?(priority=0) ~timestamp ~(header:Alpha_context.Block_header.shell_header) ~hash ctxt =
+    let contents = contents ~priority () in
+    let protocol_data =
+      let open! Alpha_context.Block_header in {
+        contents ;
+        signature = Signature.zero ;
+      } in
+    let timestamp = Alpha_environment.Time.add timestamp @@ Int64.of_int 180 in
+    Main.begin_construction
+      ~chain_id: Alpha_environment.Chain_id.zero
+      ~predecessor_context: ctxt
+      ~predecessor_timestamp: header.timestamp
+      ~predecessor_fitness: header.fitness
+      ~predecessor_level: header.level
+      ~predecessor:hash
+      ~timestamp
+      ~protocol_data
+      () >>= fun x -> Lwt.return @@ Alpha_environment.wrap_error x >>=? fun state ->
+                      return state.ctxt
+
+  let main n =
+    init n >>=? fun ((ctxt, header, hash), accounts, contracts) ->
+    let timestamp = Tezos_base.Time.now () in
+    begin_construction ~timestamp ~header ~hash ctxt >>=? fun ctxt ->
+    return (ctxt, accounts, contracts)
+
+end
+
+type identity = {
+    public_key_hash : Signature.public_key_hash;
+    public_key : Signature.public_key;
+    secret_key : Signature.secret_key;
+    implicit_contract : Alpha_context.Contract.t;
+  }
+
+type environment = {
+    tezos_context : Alpha_context.t ;
+    identities : identity list ;
+  }
+
+let init_environment () =
+  Context_init.main 10 >>=? fun (tezos_context, accounts, contracts) ->
+  let accounts = List.map fst accounts in
+  let tezos_context = Alpha_context.Gas.set_limit tezos_context @@ Z.of_int 350000 in
+  let identities =
+    List.map (fun ((a:Context_init.account), c) -> {
+                  public_key = a.pk ;
+                  public_key_hash = a.pkh ;
+                  secret_key = a.sk ;
+                  implicit_contract = c ;
+      }) @@
+      List.combine accounts contracts in
+  return {tezos_context ; identities}
+
+let contextualize ~msg ?environment f =
+  let lwt =
+    let environment = match environment with
+      | None -> init_environment ()
+      | Some x -> return x in
+    environment >>=? f
+  in
+  force_ok ~msg @@ Lwt_main.run lwt
+
+let dummy_environment =
+  X_error_monad.force_lwt ~msg:"Init_proto_alpha : initing dummy environment" @@
+  init_environment ()
--- a/vendors/ligo-utils/proto-alpha-utils/proto-alpha-utils.opam
+++ b/vendors/ligo-utils/proto-alpha-utils/proto-alpha-utils.opam
@ -0,0 +1,52 @@
+opam-version: "2.0"
+name: "proto-alpha-utils"
+version: "dev"
+synopsis: "LIGO Proto Alpha-specific Utilities, to be used by other libraries"
+maintainer: "Galfour <ligolang@gmail.com>"
+authors: "Galfour <ligolang@gmail.com>"
+license: "MIT"
+homepage: "https://gitlab.com/ligolang/ligo-utils"
+bug-reports: "https://gitlab.com/ligolang/ligo-utils/issues"
+depends: [
+  "dune"
+  "base"
+  "base"
+  "bigstring"
+  "calendar"
+  "cohttp-lwt-unix"
+  "cstruct"
+  "ezjsonm"
+  "hex"
+  "hidapi"
+  "ipaddr"
+  "irmin"
+  "js_of_ocaml"
+  "lwt"
+  "lwt_log"
+  "mtime"
+  "ocplib-endian"
+  "ocp-ocamlres"
+  "re"
+  "rresult"
+  "stdio"
+  "uri"
+  "uutf"
+  "zarith"
+  "ocplib-json-typed"
+  "ocplib-json-typed-bson"
+  "tezos-crypto"
+  "tezos-stdlib-unix"
+  "tezos-data-encoding"
+  "tezos-protocol-environment"
+  "tezos-protocol-alpha"
+  "michelson-parser"
+  "simple-utils"
+  "tezos-utils"
+  # from ppx_let:
+  "ocaml" {>= "4.04.2" & < "4.08.0"}
+  "dune"   {build & >= "1.5.1"}
+  "ppxlib" {>= "0.5.0"}
+]
+build: [
+  ["dune" "build" "-p" name]
+]
--- a/vendors/ligo-utils/proto-alpha-utils/proto_alpha_utils.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/proto_alpha_utils.ml
@ -0,0 +1,9 @@
+module Stdlib_unix = Tezos_stdlib_unix
+module Data_encoding = Tezos_data_encoding
+module Crypto = Tezos_crypto
+module Signature = Tezos_base.TzPervasives.Signature
+module Time = Tezos_base.TzPervasives.Time
+module Memory_proto_alpha = X_memory_proto_alpha
+module Error_monad = X_error_monad
+module Cast = Cast
+module Trace = Trace
--- a/vendors/ligo-utils/proto-alpha-utils/trace.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/trace.ml
@ -0,0 +1,44 @@
+include Simple_utils.Trace
+
+module AE = Memory_proto_alpha.Alpha_environment
+module TP = Tezos_base__TzPervasives
+
+let of_tz_error (err:X_error_monad.error) : error_thunk =
+  let str () = X_error_monad.(to_string err) in
+  error (thunk "alpha error") str
+
+let of_alpha_tz_error err = of_tz_error (AE.Ecoproto_error err)
+
+let trace_alpha_tzresult err : 'a AE.Error_monad.tzresult -> 'a result =
+  function
+  | Result.Ok x -> ok x
+  | Error errs -> Errors (err :: List.map of_alpha_tz_error errs)
+
+let trace_alpha_tzresult_lwt error (x:_ AE.Error_monad.tzresult Lwt.t) : _ result =
+  trace_alpha_tzresult error @@ Lwt_main.run x
+
+let trace_tzresult err =
+  function
+  | Result.Ok x -> ok x
+  | Error errs -> Errors (err :: List.map of_tz_error errs)
+
+(* TODO: should be a combination of trace_tzresult and trace_r *)
+let trace_tzresult_r err_thunk_may_fail =
+  function
+  | Result.Ok x -> ok x
+  | Error errs ->
+      let tz_errs = List.map of_tz_error errs in
+      match err_thunk_may_fail () with
+      | Simple_utils.Trace.Ok (err, annotations) -> ignore annotations; Errors (err :: tz_errs)
+      | Errors errors_while_generating_error ->
+          (* TODO: the complexity could be O(n*n) in the worst case,
+             this should use some catenable lists. *)
+          Errors (errors_while_generating_error
+                  @ tz_errs)
+
+let trace_tzresult_lwt err (x:_ TP.Error_monad.tzresult Lwt.t) : _ result =
+  trace_tzresult err @@ Lwt_main.run x
+
+let trace_tzresult_lwt_r err (x:_ TP.Error_monad.tzresult Lwt.t) : _ result =
+  trace_tzresult_r err @@ Lwt_main.run x
+
--- a/vendors/ligo-utils/proto-alpha-utils/x_error_monad.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/x_error_monad.ml
@ -0,0 +1,25 @@
+include Tezos_error_monad.Error_monad
+include Tezos_utils.Error_monad
+open Memory_proto_alpha
+
+let (>>??) = Alpha_environment.Error_monad.(>>?)
+
+let alpha_wrap a = Alpha_environment.wrap_error a
+
+let force_ok_alpha ~msg a = force_ok ~msg @@ alpha_wrap a
+
+let force_lwt ~msg a = force_ok ~msg @@ Lwt_main.run a
+
+let force_lwt_alpha ~msg a = force_ok ~msg @@ alpha_wrap @@ Lwt_main.run a
+
+let assert_error () = function
+  | Ok _ -> fail @@ failure "assert_error"
+  | Error _ -> return ()
+
+let (>>=??) a f =
+  a >>= fun a ->
+  match alpha_wrap a with
+  | Ok result -> f result
+  | Error errs -> Lwt.return (Error errs)
+
+
--- a/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml
@ -0,0 +1,133 @@
+module Michelson = Tezos_utils.Michelson
+
+include Memory_proto_alpha
+let init_environment = Init_proto_alpha.init_environment
+let dummy_environment = Init_proto_alpha.dummy_environment
+
+open X_error_monad
+open Script_typed_ir
+open Script_ir_translator
+open Script_interpreter
+
+let stack_ty_eq (type a b)
+    ?(tezos_context = dummy_environment.tezos_context)
+    (a:a stack_ty) (b:b stack_ty) =
+  alpha_wrap (Script_ir_translator.stack_ty_eq tezos_context 0 a b) >>? fun (Eq, _) ->
+  ok Eq
+
+let ty_eq (type a b)
+    ?(tezos_context = dummy_environment.tezos_context)
+    (a:a ty) (b:b ty)
+  =
+  alpha_wrap (Script_ir_translator.ty_eq tezos_context a b) >>? fun (Eq, _) ->
+  ok Eq
+
+let parse_michelson (type aft)
+    ?(tezos_context = dummy_environment.tezos_context)
+    ?(top_level = Lambda) (michelson:Michelson.t)
+    ?type_logger
+    (bef:'a Script_typed_ir.stack_ty) (aft:aft Script_typed_ir.stack_ty)
+  =
+  let michelson = Michelson.strip_annots michelson in
+  let michelson = Michelson.strip_nops michelson in
+  parse_instr
+    ?type_logger
+    top_level tezos_context
+    michelson bef >>=?? fun (j, _) ->
+  match j with
+  | Typed descr -> (
+      Lwt.return (
+        alpha_wrap (Script_ir_translator.stack_ty_eq tezos_context 0 descr.aft aft) >>? fun (Eq, _) ->
+        let descr : (_, aft) Script_typed_ir.descr = {descr with aft} in
+        Ok descr
+      )
+    )
+  | _ -> Lwt.return @@ error_exn (Failure "Typing instr failed")
+
+let parse_michelson_fail (type aft)
+    ?(tezos_context = dummy_environment.tezos_context)
+    ?(top_level = Lambda) (michelson:Michelson.t)
+    ?type_logger
+    (bef:'a Script_typed_ir.stack_ty) (aft:aft Script_typed_ir.stack_ty)
+  =
+  let michelson = Michelson.strip_annots michelson in
+  let michelson = Michelson.strip_nops michelson in
+  parse_instr
+    ?type_logger
+    top_level tezos_context
+    michelson bef >>=?? fun (j, _) ->
+  match j with
+  | Typed descr -> (
+      Lwt.return (
+        alpha_wrap (Script_ir_translator.stack_ty_eq tezos_context 0 descr.aft aft) >>? fun (Eq, _) ->
+        let descr : (_, aft) Script_typed_ir.descr = {descr with aft} in
+        Ok descr
+      )
+    )
+  | Failed { descr } ->
+      Lwt.return (Ok (descr aft))
+
+let parse_michelson_data
+    ?(tezos_context = dummy_environment.tezos_context)
+    michelson ty =
+  let michelson = Michelson.strip_annots michelson in
+  let michelson = Michelson.strip_nops michelson in
+  parse_data tezos_context ty michelson >>=?? fun (data, _) ->
+  return data
+
+let parse_michelson_ty
+    ?(tezos_context = dummy_environment.tezos_context)
+    ?(allow_big_map = true) ?(allow_operation = true)
+    michelson =
+  let michelson = Michelson.strip_annots michelson in
+  let michelson = Michelson.strip_nops michelson in
+  Lwt.return @@ parse_ty tezos_context ~allow_big_map ~allow_operation michelson >>=?? fun (ty, _) ->
+  return ty
+
+let unparse_michelson_data
+    ?(tezos_context = dummy_environment.tezos_context)
+    ?mapper ty value : Michelson.t tzresult Lwt.t =
+  Script_ir_translator.unparse_data tezos_context ?mapper
+    Readable ty value >>=?? fun (michelson, _) ->
+  return michelson
+
+let unparse_michelson_ty
+    ?(tezos_context = dummy_environment.tezos_context)
+    ty : Michelson.t tzresult Lwt.t =
+  Script_ir_translator.unparse_ty tezos_context ty >>=?? fun (michelson, _) ->
+  return michelson
+
+type options = {
+  tezos_context: Alpha_context.t ;
+  source: Alpha_context.Contract.t ;
+  payer: Alpha_context.Contract.t ;
+  self: Alpha_context.Contract.t ;
+  amount: Alpha_context.Tez.t ;
+}
+
+let make_options
+    ?(tezos_context = dummy_environment.tezos_context)
+    ?(source = (List.nth dummy_environment.identities 0).implicit_contract)
+    ?(self = (List.nth dummy_environment.identities 0).implicit_contract)
+    ?(payer = (List.nth dummy_environment.identities 1).implicit_contract)
+    ?(amount = Alpha_context.Tez.one) ()
+  = {
+    tezos_context ;
+    source ;
+    self ;
+    payer ;
+    amount ;
+  }
+
+let default_options = make_options ()
+
+let interpret ?(options = default_options) ?visitor (instr:('a, 'b) descr) (bef:'a stack) : 'b stack tzresult Lwt.t  =
+  let {
+    tezos_context ;
+    source ;
+    self ;
+    payer ;
+    amount ;
+  } = options in
+  Script_interpreter.step tezos_context ~source ~self ~payer ?visitor amount instr bef >>=??
+  fun (stack, _) -> return stack
--- a/vendors/ligo-utils/simple-utils/PP_helpers.ml
+++ b/vendors/ligo-utils/simple-utils/PP_helpers.ml
@ -0,0 +1,59 @@
+open Format
+let string : formatter -> string -> unit = fun ppf s -> fprintf ppf "%s" s
+let tag tag : formatter -> unit -> unit = fun ppf () -> fprintf ppf tag
+let bool ppf b = fprintf ppf "%b" b
+let pair f g ppf (a , b) = fprintf ppf "%a , %a" f a g b
+let new_line : formatter -> unit -> unit = tag "@;"
+let rec new_lines n ppf () =
+  match n with
+  | 0 -> new_line ppf ()
+  | n -> new_line ppf () ; new_lines (n-1) ppf ()
+let const const : formatter -> unit -> unit = fun ppf () -> fprintf ppf "%s" const
+let comment : formatter -> string -> unit = fun ppf s -> fprintf ppf "(* %s *)" s
+let list_sep value separator = pp_print_list ~pp_sep:separator value
+let list value = pp_print_list ~pp_sep:(tag "") value
+let ne_list_sep value separator ppf (hd, tl) =
+  value ppf hd ;
+  separator ppf () ;
+  pp_print_list ~pp_sep:separator value ppf tl
+
+let prepend s f ppf a =
+  fprintf ppf "%s%a" s f a
+
+let option = fun f ppf opt ->
+  match opt with
+  | Some x -> fprintf ppf "Some(%a)" f x
+  | None -> fprintf ppf "None"
+
+let lr = fun ppf lr ->
+  match lr with
+  | `Left -> fprintf ppf "left"
+  | `Right -> fprintf ppf "right"
+
+let int = fun ppf n -> fprintf ppf "%d" n
+
+let map = fun f pp ppf x ->
+  pp ppf (f x)
+
+let pair_sep value sep ppf (a, b) = fprintf ppf "%a %s %a" value a sep value b
+let smap_sep value sep ppf m =
+  let module SMap = X_map.String in
+  let lst = SMap.to_kv_list m in
+  let new_pp ppf (k, v) = fprintf ppf "%s -> %a" k value v in
+  fprintf ppf "%a" (list_sep new_pp sep) lst
+
+(* TODO: remove all uses. this is bad. *)
+let printer : ('a -> unit) -> _ -> 'a -> unit = fun f ppf x ->
+  let oldstdout = Unix.dup Unix.stdout in
+  let name = "/tmp/wtf-" ^ (string_of_int @@ Random.bits ()) in
+  let newstdout = open_out name in
+  Unix.dup2 (Unix.descr_of_out_channel newstdout) Unix.stdout;
+  f x;
+  flush stdout;
+  Unix.dup2 oldstdout Unix.stdout;
+  let ic = open_in name in
+  let n = in_channel_length ic in
+  let s = Bytes.create n in
+  really_input ic s 0 n;
+  close_in ic;
+  fprintf ppf "%s" (Bytes.to_string s)
--- a/vendors/ligo-utils/simple-utils/dictionary.ml
+++ b/vendors/ligo-utils/simple-utils/dictionary.ml
@ -0,0 +1,53 @@
+open Trace
+
+module type DICTIONARY = sig
+  type ('a, 'b) t
+
+  val get_exn : ('a, 'b) t -> 'a -> 'b
+  val get : ('a, 'b) t -> 'a -> 'b result
+
+  val set :
+    ?equal:('a -> 'a -> bool) ->
+    ('a, 'b) t -> 'a -> 'b -> ('a, 'b) t
+
+  val del :
+    ?equal:('a -> 'a -> bool) ->
+    ('a, 'b) t -> 'a -> ('a, 'b) t
+
+  val to_list : ('a, 'b) t -> ('a * 'b) list
+end
+
+module Assoc : DICTIONARY = struct
+
+  type ('a, 'b) t = ('a * 'b) list
+
+  let get_exn x y = List.assoc y x
+
+  let get x y = generic_try (simple_error "Dictionry.get") @@ fun () -> get_exn x y
+
+  let set ?equal lst a b =
+    let equal : 'a -> 'a -> bool =
+      X_option.unopt
+        ~default:(=) equal
+    in
+    let rec aux acc = function
+      | [] -> List.rev acc
+      | (key, _)::tl when equal key a -> aux ((key, b) :: acc) tl
+      | hd::tl -> aux (hd :: acc) tl
+    in
+    aux [] lst
+
+  let del ?equal lst a =
+    let equal : 'a -> 'a -> bool =
+      X_option.unopt
+        ~default:(=) equal
+    in
+    let rec aux acc = function
+      | [] -> List.rev acc
+      | (key, _)::tl when equal key a -> aux acc tl
+      | hd::tl -> aux (hd :: acc) tl
+    in
+    aux [] lst
+
+  let to_list x = x
+end
--- a/vendors/ligo-utils/simple-utils/dune
+++ b/vendors/ligo-utils/simple-utils/dune
@ -0,0 +1,9 @@
+(library
+  (name simple_utils)
+  (public_name simple-utils)
+  (libraries
+    yojson
+    unix
+    str
+  )
+)
--- a/vendors/ligo-utils/simple-utils/dune-project
+++ b/vendors/ligo-utils/simple-utils/dune-project
@ -0,0 +1 @@
+(lang dune 1.6)
--- a/vendors/ligo-utils/simple-utils/function.ml
+++ b/vendors/ligo-utils/simple-utils/function.ml
@ -0,0 +1,8 @@
+let constant x _ = x
+
+let compose = fun f g x -> f (g x)
+let (>|) = compose
+
+let compose_2 = fun f g x y -> f (g x y)
+let compose_3 = fun f g x y z -> f (g x y z)
+let compose_4 = fun f g a b c d -> f (g a b c d)
--- a/vendors/ligo-utils/simple-utils/location.ml
+++ b/vendors/ligo-utils/simple-utils/location.ml
@ -0,0 +1,37 @@
+(* type file_location = { *)
+(*   filename : string ; *)
+(*   start_line : int ; *)
+(*   start_column : int ; *)
+(*   end_line : int ; *)
+(*   end_column : int ; *)
+(* } *)
+
+type virtual_location = string
+
+type t =
+  | File of Region.t (* file_location *)
+  | Virtual of virtual_location
+
+let make (start_pos:Lexing.position) (end_pos:Lexing.position) : t =
+  (* TODO: give correct unicode offsets (the random number is here so
+     that searching for wrong souce locations appearing in messages
+     will quickly lead here *)
+  File (Region.make
+          ~start:(Pos.make ~byte:start_pos ~point_num:(-1897000) ~point_bol:(-1897000))
+          ~stop:(Pos.make ~byte:end_pos ~point_num:(-1897000) ~point_bol:(-1897000)))
+
+let virtual_location s = Virtual s
+let dummy = virtual_location "dummy"
+
+type 'a wrap = {
+  wrap_content : 'a ;
+  location : t ;
+}
+
+let wrap ~loc wrap_content = { wrap_content ; location = loc }
+let unwrap { wrap_content ; _ } = wrap_content
+let map f x = { x with wrap_content = f x.wrap_content }
+let pp_wrap f ppf { wrap_content ; _ } = Format.fprintf ppf "%a" f wrap_content
+
+let lift_region : 'a Region.reg -> 'a wrap = fun x ->
+  wrap ~loc:(File x.region) x.value
--- a/vendors/ligo-utils/simple-utils/logger.ml
+++ b/vendors/ligo-utils/simple-utils/logger.ml
@ -0,0 +1,11 @@
+module Stateful () : sig
+  val log : string -> unit
+  val get : unit -> string
+end = struct
+
+  let logger = ref ""
+  let log : string -> unit =
+    fun s -> logger := !logger ^ s
+  let get () : string = !logger
+
+end
--- a/vendors/ligo-utils/simple-utils/ne_list.ml
+++ b/vendors/ligo-utils/simple-utils/ne_list.ml
--- a/vendors/ligo-utils/simple-utils/pos.ml
+++ b/vendors/ligo-utils/simple-utils/pos.ml
@ -0,0 +1,143 @@
+type t = <
+  byte       : Lexing.position;
+  point_num  : int;
+  point_bol  : int;
+  file       : string;
+  line       : int;
+
+  set_file   : string -> t;
+  set_line   : int -> t;
+  set_offset : int -> t;
+  set        : file:string -> line:int -> offset:int -> t;
+  new_line   : string -> t;
+  add_nl     : t;
+
+  shift_bytes     : int -> t;
+  shift_one_uchar : int -> t;
+
+  offset : [`Byte | `Point] -> int;
+  column : [`Byte | `Point] -> int;
+
+  line_offset : [`Byte | `Point] -> int;
+  byte_offset : int;
+
+  is_ghost : bool;
+
+  to_string : ?offsets:bool -> [`Byte | `Point] -> string;
+  compact   : ?offsets:bool -> [`Byte | `Point] -> string;
+  anonymous : ?offsets:bool -> [`Byte | `Point] -> string
+>
+
+type pos = t
+
+(* Constructors *)
+
+let sprintf = Printf.sprintf
+
+let make ~byte ~point_num ~point_bol =
+  let () = assert (point_num >= point_bol) in
+  object (self)
+    val    byte      = byte
+    method byte      = byte
+
+    val    point_num = point_num
+    method point_num = point_num
+
+    val    point_bol = point_bol
+    method point_bol = point_bol
+
+    method set_file file =
+      {< byte = Lexing.{byte with pos_fname = file} >}
+
+    method set_line line =
+      {< byte = Lexing.{byte with pos_lnum = line} >}
+
+    method set_offset offset =
+      {< byte = Lexing.{byte with pos_cnum = byte.pos_bol + offset} >}
+
+    method set ~file ~line ~offset =
+      let pos = self#set_file file in
+      let pos = pos#set_line line in
+      let pos = pos#set_offset offset
+      in pos
+
+    (* The string must not contain '\n'. See [new_line]. *)
+
+    method shift_bytes len =
+      {< byte = Lexing.{byte with pos_cnum = byte.pos_cnum + len};
+         point_num = point_num + len >}
+
+    method shift_one_uchar len =
+      {< byte = Lexing.{byte with pos_cnum = byte.pos_cnum + len};
+         point_num = point_num + 1 >}
+
+    method add_nl =
+      {< byte = Lexing.{byte with
+                          pos_lnum = byte.pos_lnum + 1;
+                          pos_bol  = byte.pos_cnum};
+         point_bol = point_num >}
+
+    method new_line string =
+      let len = String.length string
+      in (self#shift_bytes len)#add_nl
+
+    method is_ghost = byte = Lexing.dummy_pos
+
+    method file = byte.Lexing.pos_fname
+
+    method line = byte.Lexing.pos_lnum
+
+    method offset = function
+       `Byte -> Lexing.(byte.pos_cnum - byte.pos_bol)
+    | `Point -> point_num - point_bol
+
+    method column mode = 1 + self#offset mode
+
+    method line_offset = function
+       `Byte -> byte.Lexing.pos_bol
+    | `Point -> point_bol
+
+    method byte_offset = byte.Lexing.pos_cnum
+
+    method to_string ?(offsets=true) mode =
+      let offset = self#offset mode in
+      let horizontal, value =
+        if offsets then "character", offset else "column", offset + 1
+      in sprintf "File \"%s\", line %i, %s %i"
+           self#file self#line horizontal value
+
+    method compact ?(offsets=true) mode =
+      if self#is_ghost then "ghost"
+      else
+        let offset = self#offset mode in
+        sprintf "%s:%i:%i"
+          self#file self#line (if offsets then offset else offset + 1)
+
+    method anonymous ?(offsets=true) mode =
+      if   self#is_ghost then "ghost"
+      else sprintf "%i:%i" self#line
+             (if offsets then self#offset mode else self#column mode)
+end
+
+let from_byte byte =
+  let point_num = byte.Lexing.pos_cnum
+  and point_bol = byte.Lexing.pos_bol
+  in make ~byte ~point_num ~point_bol
+
+let ghost = make ~byte:Lexing.dummy_pos ~point_num:(-1) ~point_bol:(-1)
+
+let min =
+  let byte = Lexing.{
+               pos_fname = "";
+               pos_lnum  = 1;
+               pos_bol   = 0;
+               pos_cnum  = 0}
+  in make ~byte ~point_num:0 ~point_bol:0
+
+(* Comparisons *)
+
+let equal pos1 pos2 =
+  pos1#file = pos2#file && pos1#byte_offset = pos2#byte_offset
+
+let lt pos1 pos2 =
+  pos1#file = pos2#file && pos1#byte_offset < pos2#byte_offset
--- a/vendors/ligo-utils/simple-utils/pos.mli
+++ b/vendors/ligo-utils/simple-utils/pos.mli
@ -0,0 +1,108 @@
+(* Positions in a file
+
+   A position in a file denotes a single unit belonging to it, for
+   example, in an ASCII text file, it is a particular character within
+   that file (the unit is the byte in this instance, since in ASCII
+   one character is encoded with one byte).
+
+     Units can be either bytes (as ASCII characters) or, more
+   generally, unicode points.
+
+     The type for positions is the object type [t].
+
+     We use here lexing positions to denote byte-oriented positions
+   (field [byte]), and we manage code points by means of the fields
+   [point_num] and [point_bol]. These two fields have a meaning
+   similar to the fields [pos_cnum] and [pos_bol], respectively, from
+   the standard module [Lexing]. That is to say, [point_num] holds the
+   number of code points since the beginning of the file, and
+   [point_bol] the number of code points since the beginning of the
+   current line.
+
+     The name of the file is given by the field [file], and the line
+   number by the field [line].
+*)
+
+type t = <
+  (* Payload *)
+
+  byte       : Lexing.position;
+  point_num  : int;
+  point_bol  : int;
+  file       : string;
+  line       : int;
+
+  (* Setters *)
+
+  set_file   : string -> t;
+  set_line   : int -> t;
+  set_offset : int -> t;
+  set        : file:string -> line:int -> offset:int -> t;
+
+  (* The call [pos#new_line s], where the string [s] is either "\n" or
+     "\c\r", updates the position [pos] with a new line. *)
+
+  new_line : string -> t;
+  add_nl   : t;
+
+  (* The call [pos#shift_bytes n] evaluates in a position that is the
+     translation of position [pos] of [n] bytes forward in the
+     file. The call [pos#shift_one_uchar n] is similar, except that it
+     assumes that [n] is the number of bytes making up one unicode
+     point. *)
+
+  shift_bytes     : int -> t;
+  shift_one_uchar : int -> t;
+
+  (* Getters *)
+
+  (* The call [pos#offset `Byte] provides the horizontal offset of the
+     position [pos] in bytes. (An offset is the number of units, like
+     bytes, since the beginning of the current line.) The call
+     [pos#offset `Point] is the offset counted in number of unicode
+     points.
+
+     The calls to the method [column] are similar to those to
+     [offset], except that they give the curren column number.
+
+     The call [pos#line_offset `Byte] is the offset of the line of
+     position [pos], counted in bytes. Dually, [pos#line_offset
+     `Point] counts the same offset in code points.
+
+     The call [pos#byte_offset] is the offset of the position [pos]
+     since the begininng of the file, counted in bytes.
+  *)
+
+  offset : [`Byte | `Point] -> int;
+  column : [`Byte | `Point] -> int;
+
+  line_offset : [`Byte | `Point] -> int;
+  byte_offset : int;
+
+  (* Predicates *)
+
+  is_ghost : bool;
+
+  (* Conversions to [string] *)
+
+  to_string : ?offsets:bool -> [`Byte | `Point] -> string;
+  compact   : ?offsets:bool -> [`Byte | `Point] -> string;
+  anonymous : ?offsets:bool -> [`Byte | `Point] -> string
+>
+
+type pos = t
+
+(* Constructors *)
+
+val make      : byte:Lexing.position -> point_num:int -> point_bol:int -> t
+val from_byte : Lexing.position -> t
+
+(* Special positions *)
+
+val ghost : t  (* Same as [Lexing.dummy_pos] *)
+val min   : t  (* Lexing convention: line 1, offsets to 0 and file to "". *)
+
+(* Comparisons *)
+
+val equal : t -> t -> bool
+val lt    : t -> t -> bool
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/.gitignore
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/.gitignore
@ -0,0 +1,5 @@
+_build
+*.install
+*.merlin
+_opam
+
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/CHANGES.md
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/CHANGES.md
@ -0,0 +1,17 @@
+## git version
+
+- Support for `%map.A.B.C` syntax to use values from a specific module, rather
+  than the one in scope.
+
+## v0.11
+
+- Depend on ppxlib instead of (now deprecated) ppx\_core and  ppx\_driver.
+
+## 113.43.00
+
+- Dropped `Open_in_body` support from ppx\_let, since it was only ever used
+  in confusing chains of `Let_syntax` modules that introduced other
+  `Let_syntax` modules in the "body" (e.g. for defining Commands whose
+  bodies use Async).  In this case it was decided that the better
+  practice is to be explicit with `open ___.Let_syntax` at the different
+  transition points, even though this is more verbose.
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/CONTRIBUTING.md
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/CONTRIBUTING.md
@ -0,0 +1,67 @@
+This repository contains open source software that is developed and
+maintained by [Jane Street][js].
+
+Contributions to this project are welcome and should be submitted via
+GitHub pull requests.
+
+Signing contributions
+---------------------
+
+We require that you sign your contributions. Your signature certifies
+that you wrote the patch or otherwise have the right to pass it on as
+an open-source patch. The rules are pretty simple: if you can certify
+the below (from [developercertificate.org][dco]):
+
+```
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
+```
+
+Then you just add a line to every git commit message:
+
+```
+Signed-off-by: Joe Smith <joe.smith@email.com>
+```
+
+Use your real name (sorry, no pseudonyms or anonymous contributions.)
+
+If you set your `user.name` and `user.email` git configs, you can sign
+your commit automatically with git commit -s.
+
+[dco]: http://developercertificate.org/
+[js]: https://opensource.janestreet.com/
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/CREDITS
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/CREDITS
@ -0,0 +1,4 @@
+This folder contains a generalization of ppx_let from Jane Street.
+See git log this_folder for the development history.
+
+https://github.com/janestreet/ppx_let.git
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/LICENSE.md
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/LICENSE.md
@ -0,0 +1,21 @@
+The MIT License
+
+Copyright (c) 2015--2019 Jane Street Group, LLC <opensource@janestreet.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/Makefile
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/Makefile
@ -0,0 +1,17 @@
+INSTALL_ARGS := $(if $(PREFIX),--prefix $(PREFIX),)
+
+default:
+	dune build
+
+install:
+	dune install $(INSTALL_ARGS)
+
+uninstall:
+	dune uninstall $(INSTALL_ARGS)
+
+reinstall: uninstall install
+
+clean:
+	dune clean
+
+.PHONY: default install uninstall reinstall clean
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/README.md
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/README.md
@ -0,0 +1,169 @@
+ppx_let
+=======
+
+A ppx rewriter for monadic and applicative let bindings, match expressions, and
+if expressions.
+
+Overview
+--------
+
+The aim of this rewriter is to make monadic and applicative code look nicer by
+writing custom binders the same way that we normally bind variables. In OCaml,
+the common way to bind the result of a computation to a variable is:
+
+```ocaml
+let VAR = EXPR in BODY
+```
+
+ppx\_let simply adds two new binders: `let%bind` and `let%map`. These are
+rewritten into calls to the `bind` and `map` functions respectively. These
+functions are expected to have
+
+```ocaml
+val map  : 'a t -> f:('a -> 'b)   -> 'b t
+val bind : 'a t -> f:('a -> 'b t) -> 'b t
+```
+
+for some type `t`, as one might expect.
+
+These functions are to be provided by the user, and are generally expected to be
+part of the signatures of monads and applicatives modules. This is the case for
+all monads and applicatives defined by the Jane Street's Core suite of
+libraries. (see the section below on getting the right names into scope).
+
+### Parallel bindings
+
+ppx\_let understands parallel bindings as well. i.e.:
+
+```ocaml
+let%bind VAR1 = EXPR1 and VAR2 = EXPR2 and VAR3 = EXPR3 in BODY
+```
+
+The `and` keyword is seen as a binding combination operator. To do so it expects
+the presence of a `both` function, that lifts the OCaml pair operation to the
+type `t` in question:
+
+```ocaml
+val both : 'a t -> 'b t -> ('a * 'b) t
+```
+
+### Match statements
+
+We found that this form was quite useful for match statements as well. So for
+convenience ppx\_let also accepts `%bind` and `%map` on the `match` keyword.
+Morally `match%bind expr with cases` is seen as `let%bind x = expr in match x
+with cases`.
+
+### If statements
+
+As a further convenience, ppx\_let accepts `%bind` and `%map` on the `if`
+keyword. The expression `if%bind expr1 then expr2 else expr3` is morally
+equivalent to `let%bind p = expr1 in if p then expr2 else expr3`.
+
+Syntactic forms and actual rewriting
+------------------------------------
+
+`ppx_let` adds six syntactic forms
+
+```ocaml
+let%bind P = M in E
+
+let%map  P = M in E
+
+match%bind M with P1 -> E1 | P2 -> E2 | ...
+
+match%map  M with P1 -> E1 | P2 -> E2 | ...
+
+if%bind M then E1 else E2
+
+if%map  M then E1 else E2
+```
+
+that expand into
+
+```ocaml
+bind M ~f:(fun P -> E)
+
+map  M ~f:(fun P -> E)
+
+bind M ~f:(function P1 -> E1 | P2 -> E2 | ...)
+
+map  M ~f:(function P1 -> E1 | P2 -> E2 | ...)
+
+bind M ~f:(function true -> E1 | false -> E2)
+
+map  M ~f:(function true -> E1 | false -> E2)
+```
+
+respectively.
+
+As with `let`, `let%bind` and `let%map` also support multiple *parallel*
+bindings via the `and` keyword:
+
+```ocaml
+let%bind P1 = M1 and P2 = M2 and P3 = M3 and P4 = M4 in E
+
+let%map  P1 = M1 and P2 = M2 and P3 = M3 and P4 = M4 in E
+```
+
+that expand into
+
+```ocaml
+let x1 = M1 and x2 = M2 and x3 = M3 and x4 = M4 in
+bind
+  (both x1 (both x2 (both x3 x4)))
+  ~f:(fun (P1, (P2, (P3, P4))) -> E)
+
+let x1 = M1 and x2 = M2 and x3 = M3 and x4 = M4 in
+map
+  (both x1 (both x2 (both x3 x4)))
+  ~f:(fun (P1, (P2, (P3, P4))) -> E)
+```
+
+respectively. (Instead of `x1`, `x2`, ... ppx\_let uses variable names that are
+unlikely to clash with other names)
+
+As with `let`, names introduced by left-hand sides of the let bindings are not
+available in subsequent right-hand sides of the same sequence.
+
+Getting the right names in scope
+--------------------------------
+
+The description of how the `%bind` and `%map` syntax extensions expand left out
+the fact that the names `bind`, `map`, `both`, and `return` are not used
+directly., but rather qualified by `Let_syntax`. For example, we use
+`Let_syntax.bind` rather than merely `bind`. 
+
+This means one just needs to get a properly loaded `Let_syntax` module
+in scope to use `%bind` and `%map`.
+
+Alternatively, the extension can use values from a `Let_syntax` module
+other than the one in scope. If you write `%map.A.B.C` instead of
+`%map`, the expansion will use `A.B.C.Let_syntax.map` instead of
+`Let_syntax.map` (and similarly for all extension points).
+
+For monads, `Core.Monad.Make` produces a submodule `Let_syntax` of the
+appropriate form.
+
+For applicatives, the convention for these modules is to have a submodule
+`Let_syntax` of the form:
+
+```ocaml
+module Let_syntax : sig
+  val return : 'a -> 'a t
+  val map    : 'a t -> f:('a -> 'b) -> 'b t
+  val both   : 'a t -> 'b t -> ('a * 'b) t
+  module Open_on_rhs : << some signature >>
+end
+```
+
+The `Open_on_rhs` submodule is used by variants of `%map` and `%bind` called
+`%map_open` and `%bind_open`. It is locally opened on the right hand sides of
+the rewritten let bindings in `%map_open` and `%bind_open` expressions. For
+`match%map_open` and `match%bind_open` expressions, `Open_on_rhs` is opened for
+the expression being matched on.
+
+`Open_on_rhs` is useful when programming with applicatives, which operate in a
+staged manner where the operators used to construct the applicatives are
+distinct from the operators used to manipulate the values those applicatives
+produce. For monads, `Open_on_rhs` contains `return`.
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/dune
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/dune
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/dune
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/dune
@ -0,0 +1,6 @@
+(library
+  (name ppx_let_expander)
+  (public_name simple-utils.ppx_let_generalized.expander)
+  (libraries base ppxlib)
+  (preprocess no_preprocessing)
+)
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/ppx_let_expander.ml
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/ppx_let_expander.ml
@ -0,0 +1,155 @@
+open Base
+open Ppxlib
+open Ast_builder.Default
+
+module List = struct
+  include List
+
+  let reduce_exn l ~f =
+    match l with
+    | [] -> invalid_arg "List.reduce_exn"
+    | hd :: tl -> fold_left tl ~init:hd ~f
+  ;;
+end
+
+let let_syntax ~modul : Longident.t =
+  match modul with
+  | None -> Lident "Let_syntax"
+  | Some id -> Ldot (id.txt, "Let_syntax")
+;;
+
+let open_on_rhs ~loc ~modul ~extension_name_s =
+  Located.mk ~loc (Longident.Ldot (let_syntax ~modul, "Open_on_rhs_" ^ extension_name_s))
+;;
+
+let eoperator ~loc ~modul func =
+  let lid : Longident.t = Ldot (let_syntax ~modul, func) in
+  pexp_ident ~loc (Located.mk ~loc lid)
+;;
+
+let expand_with_tmp_vars ~loc bindings expr ~f =
+  match bindings with
+  | [ _ ] -> f ~loc bindings expr
+  | _ ->
+    let tmp_vars =
+      List.map bindings ~f:(fun _ -> gen_symbol ~prefix:"__let_syntax" ())
+    in
+    let s_rhs_tmp_var (* s/rhs/tmp_var *) =
+      List.map2_exn bindings tmp_vars ~f:(fun vb var ->
+        { vb with pvb_expr = evar ~loc:vb.pvb_expr.pexp_loc var })
+    in
+    let s_lhs_tmp_var (* s/lhs/tmp_var *) =
+      List.map2_exn bindings tmp_vars ~f:(fun vb var ->
+        { vb with pvb_pat = pvar ~loc:vb.pvb_pat.ppat_loc var })
+    in
+    pexp_let ~loc Nonrecursive s_lhs_tmp_var (f ~loc s_rhs_tmp_var expr)
+;;
+
+let bind_apply ~loc ~modul extension_name_s ~arg ~fn =
+  pexp_apply
+    ~loc
+    (eoperator ~loc ~modul extension_name_s)
+    [ Nolabel, arg; Labelled "f", fn ]
+;;
+
+(* Change by Georges: Always open for all extension names. *)
+let maybe_open ~to_open:module_to_open expr =
+  let loc = expr.pexp_loc in
+  pexp_open ~loc Override (module_to_open ~loc) expr
+;;
+
+let expand_let extension_name_s ~loc ~modul bindings body =
+  if List.is_empty bindings
+  then invalid_arg "expand_let: list of bindings must be non-empty";
+  (* Build expression [both E1 (both E2 (both ...))] *)
+  let nested_boths =
+    let rev_boths = List.rev_map bindings ~f:(fun vb -> vb.pvb_expr) in
+    List.reduce_exn rev_boths ~f:(fun acc e ->
+      let loc = e.pexp_loc in
+      eapply ~loc (eoperator ~loc ~modul "both") [ e; acc ])
+  in
+  (* Build pattern [(P1, (P2, ...))] *)
+  let nested_patterns =
+    let rev_patts = List.rev_map bindings ~f:(fun vb -> vb.pvb_pat) in
+    List.reduce_exn rev_patts ~f:(fun acc p ->
+      let loc = p.ppat_loc in
+      ppat_tuple ~loc [ p; acc ])
+  in
+  bind_apply
+    ~loc
+    ~modul
+    extension_name_s
+    ~arg:nested_boths
+    ~fn:(pexp_fun ~loc Nolabel None nested_patterns body)
+;;
+
+let expand_match extension_name_s ~loc ~modul expr cases =
+  bind_apply
+    ~loc
+    ~modul
+    extension_name_s
+    ~arg:(maybe_open ~to_open:(open_on_rhs ~modul ~extension_name_s) expr)
+    ~fn:(pexp_function ~loc cases)
+;;
+
+let expand_if extension_name ~loc expr then_ else_ =
+  expand_match
+    extension_name
+    ~loc
+    expr
+    [ case ~lhs:(pbool ~loc true) ~guard:None ~rhs:then_
+    ; case ~lhs:(pbool ~loc false) ~guard:None ~rhs:else_
+    ]
+;;
+
+let expand ~modul extension_name_s expr =
+  let loc = expr.pexp_loc in
+  let expansion =
+    match expr.pexp_desc with
+    | Pexp_let (Nonrecursive, bindings, expr) ->
+      let bindings =
+        List.map bindings ~f:(fun vb ->
+          let pvb_pat =
+            (* Temporary hack tentatively detecting that the parser
+               has expanded `let x : t = e` into `let x : t = (e : t)`.
+
+               For reference, here is the relevant part of the parser:
+               https://github.com/ocaml/ocaml/blob/4.07/parsing/parser.mly#L1628 *)
+            match vb.pvb_pat.ppat_desc, vb.pvb_expr.pexp_desc with
+            | ( Ppat_constraint (p, { ptyp_desc = Ptyp_poly ([], t1); _ })
+              , Pexp_constraint (_, t2) )
+              when phys_equal t1 t2 -> p
+            | _ -> vb.pvb_pat
+          in
+          { vb with
+            pvb_pat
+          ; pvb_expr =
+              maybe_open ~to_open:(open_on_rhs ~modul ~extension_name_s) vb.pvb_expr
+          })
+      in
+      expand_with_tmp_vars ~loc bindings expr ~f:(expand_let extension_name_s ~modul)
+    | Pexp_let (Recursive, _, _) ->
+      Location.raise_errorf
+        ~loc
+        "'let%%%s' may not be recursive"
+        extension_name_s
+    | Pexp_match (expr, cases) -> expand_match extension_name_s ~loc ~modul expr cases
+    | Pexp_ifthenelse (expr, then_, else_) ->
+      let else_ =
+        match else_ with
+        | Some else_ -> else_
+        | None ->
+          Location.raise_errorf
+            ~loc
+            "'if%%%s' must include an else branch"
+            extension_name_s
+      in
+      expand_if extension_name_s ~loc ~modul expr then_ else_
+    | _ ->
+      Location.raise_errorf
+        ~loc
+        "'%%%s' can only be used with 'let', 'match', and 'if'"
+        extension_name_s
+  in
+  { expansion with pexp_attributes = expr.pexp_attributes @ expansion.pexp_attributes }
+;;
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/ppx_let_expander.mli
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/expander/ppx_let_expander.mli
@ -0,0 +1,3 @@
+open Ppxlib
+
+val expand : modul:longident loc option -> string -> expression -> expression
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/dune
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/dune
@ -0,0 +1,7 @@
+(library
+ (name ppx_let)
+ (public_name simple-utils.ppx_let_generalized)
+ (kind ppx_rewriter)
+ (libraries ppxlib ppx_let_expander)
+ (preprocess no_preprocessing)
+)
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/ppx_let.ml
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/ppx_let.ml
@ -0,0 +1,19 @@
+open Ppxlib
+
+let ext extension_name_s =
+  Extension.declare_with_path_arg
+    extension_name_s
+    Extension.Context.expression
+    Ast_pattern.(single_expr_payload __)
+    (fun ~loc:_ ~path:_ ~arg expr ->
+       Ppx_let_expander.expand extension_name_s ~modul:arg expr)
+;;
+
+let () =
+  Driver.register_transformation
+    "let"
+    ~extensions:(List.map ext [
+      "bind";
+      "xxx";
+    ])
+;;
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/ppx_let.mli
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/src/ppx_let.mli
@ -0,0 +1 @@
+
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/dune
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/dune
@ -0,0 +1 @@
+(executables (names test) (preprocess (pps ppx_let_generalized)))
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/test-locations.mlt
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/test-locations.mlt
@ -0,0 +1,27 @@
+(* -*- tuareg -*- *)
+
+module Let_syntax = struct
+  type 'a t = T of 'a
+
+  let map (T x) ~f = T (f x)
+  let both (T x) (T y) = T (x, y)
+
+  module Open_on_rhs = struct
+    let return x = T x
+    let f x ~(doc : string) = T (x, doc)
+  end
+end
+
+let _ =
+  [%map_open
+    let x = return 42
+    and y = f 42 in
+    ()]
+;;
+
+[%%expect
+  {|
+Line _, characters 12-16:
+Error: This expression has type doc:string -> (int * string) Let_syntax.t
+       but an expression was expected of type 'a Let_syntax.t
+|}]
--- a/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/test.ml
+++ b/vendors/ligo-utils/simple-utils/ppx_let_generalized/test/test.ml
@ -0,0 +1,189 @@
+module Monad_example = struct
+  module Let_syntax = struct
+    let bind x ~f = f x
+    module Open_on_rhs_bind = struct
+      let return _ = "foo"
+    end
+  end
+
+  let _mf a =
+    let%bind xyz = return a in
+    (int_of_string xyz + 1)
+  ;;
+end
+
+(* TODO: re-enable some tests *)
+
+(*
+module Monad_example = struct
+  module X : sig
+    type 'a t
+
+    module Let_syntax : sig
+      val return : 'a -> 'a t
+
+      module Let_syntax : sig
+        val return : 'a -> 'a t
+        val bind : 'a t -> f:('a -> 'b t) -> 'b t
+        val map : 'a t -> f:('a -> 'b) -> 'b t
+        val both : 'a t -> 'b t -> ('a * 'b) t
+
+        module Open_on_rhs : sig
+          val return : 'a -> 'a t
+        end
+      end
+    end
+  end = struct
+    type 'a t = 'a
+
+    let return x = x
+    let bind x ~f = f x
+    let map x ~f = f x
+    let both x y = x, y
+
+    module Let_syntax = struct
+      let return = return
+
+      module Let_syntax = struct
+        let return = return
+        let bind = bind
+        let map = map
+        let both = both
+
+        module Open_on_rhs = struct
+          let return = return
+        end
+      end
+    end
+  end
+
+  open X.Let_syntax
+
+  let _mf a : _ X.t =
+    let%bind_open x = a in
+    return (x + 1)
+  ;;
+
+  let _mf' a b c : _ X.t =
+    let%bind_open x = a
+    and y = b
+    and u, v = c in
+    return (x + y + (u * v))
+  ;;
+
+  let _mg a : _ X.t =
+    let%map x : int X.t = a in
+    x + 1
+  ;;
+
+  let _mg' a b c : _ X.t =
+    let%map x = a
+    and y = b
+    and u, v = c in
+    x + y + (u * v)
+  ;;
+
+  let _mh a : _ X.t =
+    match%bind_open a with
+    | 0 -> return true
+    | _ -> return false
+  ;;
+
+  let _mi a : _ X.t =
+    match%map a with
+    | 0 -> true
+    | _ -> false
+  ;;
+
+  let _mif a : _ X.t = if%bind_open a then return true else return false
+  let _mif' a : _ X.t = if%map a then true else false
+end
+
+module Applicative_example = struct
+  module X : sig
+    type 'a t
+
+    module Let_syntax : sig
+      val return : 'a -> 'a t
+
+      module Let_syntax : sig
+        val return : 'a -> 'a t
+        val map : 'a t -> f:('a -> 'b) -> 'b t
+        val both : 'a t -> 'b t -> ('a * 'b) t
+
+        module Open_on_rhs : sig
+          val flag : int t
+          val anon : int t
+        end
+      end
+    end
+  end = struct
+    type 'a t = 'a
+
+    let return x = x
+    let map x ~f = f x
+    let both x y = x, y
+
+    module Let_syntax = struct
+      let return = return
+
+      module Let_syntax = struct
+        let return = return
+        let map = map
+        let both = both
+
+        module Open_on_rhs = struct
+          let flag = 66
+          let anon = 77
+        end
+      end
+    end
+  end
+
+  open X.Let_syntax
+
+  (* {[
+       let _af a : _ X.t =
+         let%bind x = a in (* "Error: Unbound value Let_syntax.bind" *)
+         return (x + 1)
+     ]} *)
+
+  (* {[
+       let _af' a b c : _ X.t =
+         let%bind x = a and y = b and (u, v) = c in (* "Error: Unbound value Let_syntax.bind" *)
+         return (x + y + (u * v))
+     ]} *)
+
+  let _ag a : _ X.t =
+    let%map x = a in
+    x + 1
+  ;;
+
+  let _ag' a b c : _ X.t =
+    let%map x = a
+    and y = b
+    and u, v = c in
+    x + y + (u * v)
+  ;;
+
+  (* {[
+       let _ah a : _ X.t =
+         match%bind a with (* "Error: Unbound value Let_syntax.bind" *)
+         | 0 -> return true
+         | _ -> return false
+     ]} *)
+
+  let _ai a : _ X.t =
+    match%map a with
+    | 0 -> true
+    | _ -> false
+  ;;
+end
+
+module Example_without_open = struct
+  let _ag a : _ Applicative_example.X.t =
+    let%map.Applicative_example.X.Let_syntax x = a in
+    x + 1
+  ;;
+end
+*)
--- a/vendors/ligo-utils/simple-utils/region.ml
+++ b/vendors/ligo-utils/simple-utils/region.ml
@ -0,0 +1,128 @@
+(* Regions of a file *)
+
+let sprintf = Printf.sprintf
+
+type t = <
+  start : Pos.t;
+  stop  : Pos.t;
+
+  (* Setters *)
+
+  shift_bytes     : int -> t;
+  shift_one_uchar : int -> t;
+  set_file        : string -> t;
+
+  (* Getters *)
+
+  file      : string;
+  pos       : Pos.t * Pos.t;
+  byte_pos  : Lexing.position * Lexing.position;
+
+  (* Predicates *)
+
+  is_ghost : bool;
+
+  (* Conversions to [string] *)
+
+  to_string : ?file:bool -> ?offsets:bool -> [`Byte | `Point] -> string;
+  compact   : ?file:bool -> ?offsets:bool -> [`Byte | `Point] -> string
+>
+
+type region = t
+
+type 'a reg = {region: t; value: 'a}
+
+(* Injections *)
+
+exception Invalid
+
+let make ~(start: Pos.t) ~(stop: Pos.t) =
+  if start#file <> stop#file || start#byte_offset > stop#byte_offset
+  then raise Invalid
+  else
+    object
+      val    start = start
+      method start = start
+      val    stop  = stop
+      method stop  = stop
+
+      method shift_bytes len =
+        let start = start#shift_bytes len
+        and stop  = stop#shift_bytes len
+        in {< start = start; stop = stop >}
+
+      method shift_one_uchar len =
+        let start = start#shift_one_uchar len
+        and stop  = stop#shift_one_uchar len
+        in {< start = start; stop = stop >}
+
+      method set_file name =
+        let start = start#set_file name
+        and stop  = stop#set_file name
+        in {< start = start; stop = stop >}
+
+      (* Getters *)
+
+      method file      = start#file
+      method pos       = start, stop
+      method byte_pos  = start#byte, stop#byte
+
+      (* Predicates *)
+
+      method is_ghost = start#is_ghost && stop#is_ghost
+
+      (* Conversions to strings *)
+
+      method to_string ?(file=true) ?(offsets=true) mode =
+        let horizontal = if offsets then "character" else "column"
+        and start_offset =
+          if offsets then start#offset mode else start#column mode
+        and stop_offset =
+          if offsets then stop#offset mode else stop#column mode in
+        let info =
+          if   file
+          then sprintf "in file \"%s\", line %i, %s"
+                 (String.escaped start#file) start#line horizontal
+          else sprintf "at line %i, %s" start#line horizontal
+        in if   stop#line = start#line
+           then sprintf "%ss %i-%i" info start_offset stop_offset
+           else sprintf "%s %i to line %i, %s %i"
+                  info start_offset stop#line horizontal stop_offset
+
+      method compact ?(file=true) ?(offsets=true) mode =
+        let start_str = start#anonymous ~offsets mode
+        and stop_str  = stop#anonymous ~offsets mode in
+        if start#file = stop#file then
+          if file then sprintf "%s:%s-%s" start#file start_str stop_str
+          else sprintf "%s-%s" start_str stop_str
+        else sprintf "%s:%s-%s:%s" start#file start_str stop#file stop_str
+    end
+
+(* Special regions *)
+
+let ghost = make ~start:Pos.ghost ~stop:Pos.ghost
+
+let min = make ~start:Pos.min ~stop:Pos.min
+
+(* Comparisons *)
+
+let equal r1 r2 =
+   r1#file = r2#file
+&& Pos.equal r1#start r2#start
+&& Pos.equal r1#stop  r2#stop
+
+let lt r1 r2 =
+  r1#file = r2#file
+&& not r1#is_ghost
+&& not r2#is_ghost
+&& Pos.lt r1#start r2#start
+&& Pos.lt r1#stop  r2#stop
+
+let cover r1 r2 =
+  if r1#is_ghost
+  then r2
+  else if r2#is_ghost
+       then r1
+       else if   lt r1 r2
+            then make ~start:r1#start ~stop:r2#stop
+            else make ~start:r2#start ~stop:r1#stop
--- a/vendors/ligo-utils/simple-utils/region.mli
+++ b/vendors/ligo-utils/simple-utils/region.mli
@ -0,0 +1,125 @@
+(* Regions of a file
+
+   A _region_ is a contiguous series of bytes, for example, in a text
+   file. It is here denoted by the object type [t].
+
+     The start (included) of the region is given by the field [start],
+   which is a _position_, and the end (excluded) is the position given
+   by the field [stop]. The convention of including the start and
+   excluding the end enables to have empty regions if, and only if,
+   [start = stop]. See module [Pos] for the definition of positions.
+
+     The first byte of a file starts at the offset zero (that is,
+   column one), and [start] is always lower than or equal to [stop],
+   and they must refer to the same file.
+*)
+
+type t = <
+  start : Pos.t;
+  stop  : Pos.t;
+
+  (* Setters *)
+
+  (* The call [region#shift_bytes n] evaluates in a region that is the
+     translation of region [region] of [n] bytes forward in the
+     file. The call [region#shift_one_uchar n] is similar, except that
+     it assumes that [n] is the number of bytes making up one unicode
+     point. The call [region#set_file f] sets the file name to be
+     [f]. *)
+
+  shift_bytes     : int -> t;
+  shift_one_uchar : int -> t;
+  set_file        : string -> t;
+
+  (* Getters *)
+
+  (* The method [file] returns the file name.
+     The method [pos] returns the values of the fields [start] and [stop].
+     The method [byte_pos] returns the start and end positions of the
+     region at hand _interpreting them as lexing positions_, that is,
+     the unit is the byte. *)
+
+  file     : string;
+  pos      : Pos.t * Pos.t;
+  byte_pos : Lexing.position * Lexing.position;
+
+  (* Predicates *)
+
+  is_ghost : bool;
+
+  (* Conversions to [string] *)
+
+  (* The call [region#to_string ~file ~offsets mode] evaluates in a
+     string denoting the region [region].
+
+     The name of the file is present if, and only if, [file = true] or
+     [file] is missing.
+
+     The positions in the file are expressed horizontal offsets if
+     [offsets = true] or [offsets] is missing (the default), otherwise
+     as columns.
+
+     If [mode = `Byte], those positions will be assumed to have bytes
+     as their unit, otherwise, if [mode = `Point], they will be
+     assumed to refer to code points.
+
+     The method [compact] has the same signature and calling
+     convention as [to_string], except that the resulting string is
+     more compact.
+   *)
+
+  to_string : ?file:bool -> ?offsets:bool -> [`Byte | `Point] -> string;
+  compact   : ?file:bool -> ?offsets:bool -> [`Byte | `Point] -> string
+>
+
+type region = t
+
+type 'a reg = {region: t; value: 'a}
+
+(* Constructors *)
+
+(* The function [make] creates a region from two positions. If the
+   positions are not properly ordered or refer to different files, the
+   exception [Invalid] is raised. *)
+
+exception Invalid
+
+val make : start:Pos.t -> stop:Pos.t -> t
+
+(* Special regions *)
+
+(* To deal with ghost expressions, that is, pieces of abstract syntax
+   that have not been built from excerpts of concrete syntax, we need
+   _ghost regions_. The module [Pos] provides a [ghost] position, and
+   we also provide a [ghost] region and, in type [t], the method
+   [is_ghost] to check it. *)
+
+val ghost : t (* Two [Pos.ghost] positions *)
+
+(* Occasionnally, we may need a minimum region. It is here made of two
+   minimal positions. *)
+
+val min : t (* Two [Pos.min] positions *)
+
+(* Comparisons *)
+
+(* Two regions are equal if, and only if, they refer to the same file
+   and their start positions are equal and their stop positions are
+   equal. See [Pos.equal]. Note that [r1] and [r2] can be ghosts. *)
+
+val equal : t -> t -> bool
+
+(* The call [lt r1 r2] ("lower than") has the value [true] if, and
+   only if, regions [r1] and [r2] refer to the same file, none is a
+   ghost and the start position of [r1] is lower than that of
+   [r2]. (See [Pos.lt].) *)
+
+val lt : t -> t -> bool
+
+(* Given two regions [r1] and [r2], we may want the region [cover r1
+   r2] that covers [r1] and [r2]. We property [equal (cover r1 r2)
+   (cover r2 r1)]. (In a sense, it is the maximum region, but we avoid
+   that name because of the [min] function above.) If [r1] is a ghost,
+   the cover is [r2], and if [r2] is a ghost, the cover is [r1]. *)
+
+val cover : t -> t -> t
--- a/vendors/ligo-utils/simple-utils/simple-utils.opam
+++ b/vendors/ligo-utils/simple-utils/simple-utils.opam
@ -0,0 +1,50 @@
+opam-version: "2.0"
+name: "simple-utils"
+version: "dev"
+synopsis: "LIGO Utilities, to be used by other libraries"
+maintainer: "Galfour <ligolang@gmail.com>"
+authors: "Galfour <ligolang@gmail.com>"
+license: "MIT"
+homepage: "https://gitlab.com/ligolang/ligo-utils"
+bug-reports: "https://gitlab.com/ligolang/ligo-utils/issues"
+depends: [
+  "dune"
+  "base"
+  "base"
+  "bigstring"
+  "calendar"
+  "cohttp-lwt-unix"
+  "cstruct"
+  "ezjsonm"
+  "hex"
+  "hidapi"
+  "ipaddr"
+  "irmin"
+  "js_of_ocaml"
+  "lwt"
+  "lwt_log"
+  "mtime"
+  "ocplib-endian"
+  "ocp-ocamlres"
+  "re"
+  "rresult"
+  "stdio"
+  "uri"
+  "uutf"
+  "zarith"
+  "ocplib-json-typed"
+  "ocplib-json-typed-bson"
+  "tezos-crypto"
+  "tezos-stdlib-unix"
+  "tezos-data-encoding"
+  "tezos-protocol-environment"
+  "tezos-protocol-alpha"
+  "michelson-parser"
+  # from ppx_let:
+  "ocaml" {>= "4.04.2" & < "4.08.0"}
+  "dune"   {build & >= "1.5.1"}
+  "ppxlib" {>= "0.5.0"}
+]
+build: [
+  ["dune" "build" "-p" name]
+]
--- a/vendors/ligo-utils/simple-utils/simple_utils.ml
+++ b/vendors/ligo-utils/simple-utils/simple_utils.ml
@ -0,0 +1,15 @@
+module Function = Function
+module Trace = Trace
+module Logger = Logger
+module PP_helpers = PP_helpers
+module Location = Location
+
+module List = X_list
+module Option = X_option
+module Tuple = Tuple
+module Map = X_map
+module Dictionary = Dictionary
+module Tree = Tree
+module Region = Region
+module Pos = Pos
+
--- a/vendors/ligo-utils/simple-utils/trace.ml
+++ b/vendors/ligo-utils/simple-utils/trace.ml
@ -0,0 +1,370 @@
+module J = Yojson.Basic
+
+type error = [`Assoc of (string * J.t) list]
+
+module JSON_string_utils = struct
+  let member = J.Util.member
+  let string = J.Util.to_string_option
+  let int = J.Util.to_int_option
+
+  let swap f l r = f r l
+
+  let unit x = Some x
+  let bind f = function None -> None | Some x -> Some (f x)
+  let bind2 f = fun l r -> match l, r with
+      None,   None   -> None
+    | None,   Some _ -> None
+    | Some _, None   -> None
+    | Some l, Some r -> Some (f l r)
+
+  let default d = function
+      Some x -> x
+    | None -> d
+
+  let string_of_int = bind string_of_int
+
+  let (||) l r = l |> default r
+  let (|^) = bind2 (^)
+end
+
+let mk_error ?(error_code : int option) ~(title : string) ?(message : string option) () =
+  let collapse l =
+    List.fold_left (fun acc -> function None -> acc | Some e -> e::acc) [] (List.rev l) in
+  `Assoc
+    (collapse
+       [(match error_code with Some c -> Some ("error_code", `Int c) | None -> None);
+        Some ("title", `String title);
+        (match message with Some m -> Some ("message", `String m) | None -> None)])
+
+
+type error_thunk = unit -> error
+
+type annotation = J.t (* feel free to add different annotations here. *)
+type annotation_thunk = unit -> annotation
+
+type 'a result =
+    Ok of 'a * annotation_thunk list
+  | Errors of error_thunk list
+
+let ok x = Ok (x, [])
+let fail err = Errors [err]
+
+(* When passing a constant string where a thunk is expected, we wrap it with thunk, as follows:
+   (thunk "some string")
+   We always put the parentheses around the call, to increase grep and sed efficiency.
+
+   When a trace function is called, it is passed a `(fun () -> …)`.
+   If the `…` is e.g. error then we write `(fun () -> error title msg ()` *)
+let thunk x () = x
+
+let error title message () = mk_error ~title:(title ()) ~message:(message ()) ()
+
+let simple_error str () = mk_error ~title:str ()
+
+let simple_fail str = fail @@ simple_error str
+
+(* To be used when wrapped by a "trace_strong" for instance *)
+let dummy_fail = simple_fail "dummy"
+
+let map f = function
+  | Ok (x, annotations) ->
+      (match f x with
+         Ok (x', annotations') -> Ok (x', annotations' @ annotations)
+       | Errors _ as e' -> ignore annotations; e')
+  | Errors _ as e -> e
+
+let apply f = function
+  | Ok (x, annotations) -> Ok (f x, annotations)
+  | Errors _ as e -> e
+
+let (>>?) x f = map f x
+let (>>|?) = apply
+
+module Let_syntax = struct
+  let bind m ~f = m >>? f
+  module Open_on_rhs_bind = struct end
+end
+
+let trace_strong err = function
+  | Ok _ as o -> o
+  | Errors _ -> Errors [err]
+
+let trace err = function
+  | Ok _ as o -> o
+  | Errors errs -> Errors (err :: errs)
+
+let trace_r err_thunk_may_fail = function
+  | Ok _ as o -> o
+  | Errors errs ->
+      match err_thunk_may_fail () with
+      | Ok (err, annotations) -> ignore annotations; Errors (err :: errs)
+      | Errors errors_while_generating_error ->
+          (* TODO: the complexity could be O(n*n) in the worst case,
+             this should use some catenable lists. *)
+          Errors (errors_while_generating_error
+                  @ errs)
+
+let trace_f f error x =
+  trace error @@ f x
+
+let trace_f_2 f error x y =
+  trace error @@ f x y
+
+let trace_f_ez f name =
+  trace_f f (error (thunk "in function") name)
+
+let trace_f_2_ez f name =
+  trace_f_2 f (error (thunk "in function") name)
+
+let to_bool = function
+  | Ok _ -> true
+  | Errors _ -> false
+
+let to_option = function
+  | Ok (o, annotations) -> ignore annotations; Some o
+  | Errors _ -> None
+
+let trace_option error = function
+  | None -> fail error
+  | Some s -> ok s
+
+let bind_map_option f = function
+  | None -> ok None
+  | Some s -> f s >>? fun x -> ok (Some x)
+
+let rec bind_list = function
+  | [] -> ok []
+  | hd :: tl -> (
+      hd >>? fun hd ->
+      bind_list tl >>? fun tl ->
+      ok @@ hd :: tl
+    )
+let bind_ne_list = fun (hd , tl) ->
+  hd >>? fun hd ->
+  bind_list tl >>? fun tl ->
+  ok @@ (hd , tl)
+
+let bind_smap (s:_ X_map.String.t) =
+  let open X_map.String in
+  let aux k v prev =
+    prev >>? fun prev' ->
+    v >>? fun v' ->
+    ok @@ add k v' prev' in
+  fold aux s (ok empty)
+
+let bind_fold_smap f init (smap : _ X_map.String.t) =
+  let aux k v prev =
+    prev >>? fun prev' ->
+    f prev' k v
+  in
+  X_map.String.fold aux smap init
+
+let bind_map_smap f smap = bind_smap (X_map.String.map f smap)
+
+let bind_map_list f lst = bind_list (List.map f lst)
+let bind_map_ne_list : _ -> 'a X_list.Ne.t -> 'b X_list.Ne.t result = fun f lst -> bind_ne_list (X_list.Ne.map f lst)
+let bind_iter_list : (_ -> unit result) -> _ list -> unit result = fun f lst ->
+  bind_map_list f lst >>? fun _ -> ok ()
+
+let bind_location (x:_ Location.wrap) =
+  x.wrap_content >>? fun wrap_content ->
+  ok { x with wrap_content }
+
+let bind_map_location f x = bind_location (Location.map f x)
+
+let bind_fold_list f init lst =
+  let aux x y =
+    x >>? fun x ->
+    f x y
+  in
+  List.fold_left aux (ok init) lst
+
+let bind_fold_map_list = fun f acc lst ->
+  let rec aux (acc , prev) f = function
+    | [] -> ok (acc , prev)
+    | hd :: tl ->
+        f acc hd >>? fun (acc' , hd') ->
+        aux (acc' , hd' :: prev) f tl
+  in
+  aux (acc , []) f lst >>? fun (_acc' , lst') ->
+  ok @@ List.rev lst'
+
+let bind_fold_map_right_list = fun f acc lst ->
+  let rec aux (acc , prev) f = function
+    | [] -> ok (acc , prev)
+    | hd :: tl ->
+        f acc hd >>? fun (acc' , hd') ->
+        aux (acc' , hd' :: prev) f tl
+  in
+  aux (acc , []) f (List.rev lst) >>? fun (_acc' , lst') ->
+  ok lst'
+
+let bind_fold_right_list f init lst =
+  let aux x y =
+    x >>? fun x ->
+    f x y
+  in
+  X_list.fold_right' aux (ok init) lst
+
+let bind_find_map_list error f lst =
+  let rec aux lst =
+    match lst with
+    | [] -> fail error
+    | hd :: tl -> (
+        match f hd with
+        | Errors _ -> aux tl
+        | o -> o
+      )
+  in
+  aux lst
+
+let bind_list_iter f lst =
+  let aux () y = f y in
+  bind_fold_list aux () lst
+
+let bind_or (a, b) =
+  match a with
+  | Ok _ as o -> o
+  | _ -> b
+
+let bind_lr (type a b) ((a : a result), (b:b result)) : [`Left of a | `Right of b] result =
+  match (a, b) with
+  | (Ok _ as o), _ -> apply (fun x -> `Left x) o
+  | _, (Ok _ as o) -> apply (fun x -> `Right x) o
+  | _, Errors b -> Errors b
+
+let bind_lr_lazy (type a b) ((a : a result), (b:unit -> b result)) : [`Left of a | `Right of b] result =
+  match a with
+  | Ok _ as o -> apply (fun x -> `Left x) o
+  | _ -> (
+      match b() with
+      | Ok _ as o -> apply (fun x -> `Right x) o
+      | Errors b -> Errors b
+    )
+
+let bind_and (a, b) =
+  a >>? fun a ->
+  b >>? fun b ->
+  ok (a, b)
+
+let bind_pair = bind_and
+let bind_map_pair f (a, b) =
+  bind_pair (f a, f b)
+
+let generic_try err f =
+  try (
+    ok @@ f ()
+  ) with _ -> fail err
+
+let specific_try handler f =
+  try (
+    ok @@ f ()
+  ) with exn -> fail ((handler ()) exn)
+
+let sys_try f =
+  let handler () = function
+    | Sys_error str -> error (thunk "Sys_error") (fun () -> str)
+    | exn -> raise exn
+  in
+  specific_try handler f
+
+let sys_command command =
+  sys_try (fun () -> Sys.command command) >>? function
+  | 0 -> ok ()
+  | n -> fail (fun () -> error (thunk "Nonzero return code") (fun () -> (string_of_int n)) ())
+
+let trace_sequence f lst =
+  let lazy_map_force : 'a . (unit -> 'a) list -> (unit -> 'a list) = fun l ->
+    fun () ->
+    List.rev @@ List.rev_map (fun a -> a ()) l in
+  let rec aux acc_x acc_annotations = function
+    | hd :: tl -> (
+        match f hd with
+        (* TODO: what should we do with the annotations? *)
+        | Ok (x, annotations) -> aux (x :: acc_x) (lazy_map_force annotations :: acc_annotations) tl
+        | Errors _ as errs -> errs
+      )
+    | [] ->
+        let old_annotations () = List.map (fun a -> `List (a ())) @@ List.rev acc_annotations in
+        (* Builds a JSON annotation { "type": "list"; "content": [[…], …] } *)
+        let annotation = fun () -> `Assoc [("type", `String "list"); ("content", `List (old_annotations ()))]
+        in Ok (List.rev acc_x, [annotation]) in
+  aux [] lst
+
+let json_of_error = J.to_string
+let error_pp out (e : error) =
+  let open JSON_string_utils in
+  let e : J.t = (match e with `Assoc _ as e -> e) in
+  let message    = e |> member "message"    |> string in
+  let title      = e |> member "title"      |> string || "(no title)" in
+  let error_code = unit " " |^ (e |> member "error_code" |> int |> string_of_int) || "" in
+  Format.fprintf out "%s" (error_code ^ ": " ^ title ^ (unit ":" |^ message  || ""))
+
+let error_pp_short out (e : error) =
+  let open JSON_string_utils in
+  let e : J.t = (match e with `Assoc _ as e -> e) in
+  let title      = e |> member "title"      |> string || "(no title)" in
+  let error_code = unit " " |^ (e |> member "error_code" |> int |> string_of_int) || "" in
+  Format.fprintf out "%s" (error_code ^ ": " ^ title)
+
+let errors_pp =
+  Format.pp_print_list
+    ~pp_sep:Format.pp_print_newline
+    error_pp
+
+let errors_pp_short =
+  Format.pp_print_list
+    ~pp_sep:Format.pp_print_newline
+    error_pp_short
+
+let pp_to_string pp () x =
+  Format.fprintf Format.str_formatter "%a" pp x ;
+  Format.flush_str_formatter ()
+
+let errors_to_string = pp_to_string errors_pp
+
+module Assert = struct
+  let assert_fail ?(msg="didn't fail") = function
+    | Ok _ -> simple_fail msg
+    | _ -> ok ()
+
+  let assert_true ?(msg="not true") = function
+    | true -> ok ()
+    | false -> simple_fail msg
+
+  let assert_equal ?msg expected actual =
+    assert_true ?msg (expected = actual)
+
+  let assert_equal_int ?msg expected actual =
+    let msg =
+      let default = Format.asprintf "Not equal int : expected %d, got %d" expected actual in
+      X_option.unopt ~default msg in
+    assert_equal ~msg expected actual
+
+  let assert_equal_bool ?msg expected actual =
+    let msg =
+      let default = Format.asprintf "Not equal bool : expected %b, got %b" expected actual in
+      X_option.unopt ~default msg in
+    assert_equal ~msg expected actual
+
+  let assert_none ?(msg="not a none") opt = match opt with
+    | None -> ok ()
+    | _ -> simple_fail msg
+
+  let assert_list_size ?(msg="lst doesn't have the right size") lst n =
+    assert_true ~msg List.(length lst = n)
+
+  let assert_list_empty ?(msg="lst isn't empty") lst =
+    assert_true ~msg List.(length lst = 0)
+
+  let assert_list_same_size ?(msg="lists don't have same size") a b =
+    assert_true ~msg List.(length a = length b)
+
+  let assert_list_size_2 ~msg = function
+    | [a;b] -> ok (a, b)
+    | _ -> simple_fail msg
+
+  let assert_list_size_1 ~msg = function
+    | [a] -> ok a
+    | _ -> simple_fail msg
+end
--- a/vendors/ligo-utils/simple-utils/tree.ml
+++ b/vendors/ligo-utils/simple-utils/tree.ml
@ -0,0 +1,130 @@
+[@@@warning "-9"]
+
+module Append = struct
+  type 'a t' =
+    | Leaf of 'a
+    | Node of {
+        a : 'a t' ;
+        b : 'a t' ;
+        size : int ;
+        full : bool ;
+      }
+
+  type 'a t =
+    | Empty
+    | Full of 'a t'
+
+  let node (a, b, size, full) = Node {a;b;size;full}
+
+  let rec exists' f = function
+    | Leaf s' when f s' -> true
+    | Leaf _ -> false
+    | Node{a;b} -> exists' f a || exists' f b
+  let exists f = function
+    | Empty -> false
+    | Full x -> exists' f x
+
+  let rec exists_path' f = function
+    | Leaf x -> if f x then Some [] else None
+    | Node {a;b} -> (
+      match exists_path' f a with
+      | Some a -> Some (false :: a)
+      | None -> (
+        match exists_path' f b with
+        | Some b -> Some (true :: b)
+        | None -> None
+      )
+    )
+
+  let exists_path f = function
+    | Empty -> None
+    | Full x -> exists_path' f x
+
+  let empty : 'a t = Empty
+
+  let size' = function
+    | Leaf _ -> 1
+    | Node {size} -> size
+
+  let size = function
+    | Empty -> 0
+    | Full x -> size' x
+
+  let rec append' x = function
+    | Leaf e -> node (Leaf e, Leaf x, 1, true)
+    | Node({full=true;size}) as n -> node(n, Leaf x, size + 1, false)
+    | Node({a=Node a;b;full=false} as n) -> (
+      match append' x b with
+      | Node{full=false} as b -> Node{n with b}
+      | Node({full=true} as b) -> Node{n with b = Node b ; full = b.size = a.size}
+      | Leaf _ -> assert false
+    )
+    | Node{a=Leaf _;full=false} -> assert false
+
+  let append x = function
+    | Empty -> Full (Leaf x)
+    | Full t -> Full (append' x t)
+
+  let of_list lst =
+    let rec aux = function
+      | [] -> Empty
+      | hd :: tl -> append hd (aux tl)
+    in
+    aux @@ List.rev lst
+
+  let rec to_list' t' =
+    match t' with
+    | Leaf x -> [x]
+    | Node {a;b} -> (to_list' a) @ (to_list' b)
+
+  let to_list t =
+    match t with
+    | Empty -> []
+    | Full x -> to_list' x
+
+  let rec fold' leaf node = function
+    | Leaf x -> leaf x
+    | Node {a;b} -> node (fold' leaf node a) (fold' leaf node b)
+
+  let rec fold_s' : type a b . a -> (a -> b -> a) -> b t' -> a  = fun init leaf -> function
+    | Leaf x -> leaf init x
+    | Node {a;b} -> fold_s' (fold_s' init leaf a) leaf b
+
+  let fold_ne leaf node = function
+    | Empty -> raise (Failure "Tree.Append.fold_ne")
+    | Full x -> fold' leaf node x
+
+  let fold_s_ne : type a b . a -> (a -> b -> a) -> b t -> a = fun init leaf -> function
+    | Empty -> raise (Failure "Tree.Append.fold_s_ne")
+    | Full x -> fold_s' init leaf x
+
+  let fold empty leaf node = function
+    | Empty -> empty
+    | Full x -> fold' leaf node x
+
+
+  let rec assoc_opt' : ('a * 'b) t' -> 'a -> 'b option = fun t k ->
+    match t with
+    | Leaf (k', v) when k = k' -> Some v
+    | Leaf _ -> None
+    | Node {a;b} -> (
+        match assoc_opt' a k with
+        | None -> assoc_opt' b k
+        | Some v -> Some v
+      )
+
+  let assoc_opt : ('a * 'b) t -> 'a -> 'b option = fun t k ->
+    match t with
+    | Empty -> None
+    | Full t' -> assoc_opt' t' k
+
+  let rec pp' : _ -> _ -> 'a t' -> unit = fun f ppf t' ->
+    match t' with
+    | Leaf x -> Format.fprintf ppf "%a" f x
+    | Node {a;b} -> Format.fprintf ppf "N(%a , %a)" (pp' f) a (pp' f) b
+
+  let pp : _ -> _ -> 'a t -> unit = fun f ppf t ->
+    match t with
+    | Empty -> Format.fprintf ppf "[]"
+    | Full x -> Format.fprintf ppf "[%a]" (pp' f) x
+end
--- a/vendors/ligo-utils/simple-utils/tuple.ml
+++ b/vendors/ligo-utils/simple-utils/tuple.ml
@ -0,0 +1,9 @@
+let map_h_2 f g (a , b) = (f a , g b)
+let map2 f (a, b) = (f a, f b)
+let apply2 f (a, b) = f a b
+let list2 (a, b) = [a;b]
+
+module Pair = struct
+  let map = map2
+  let apply f (a, b) = f a b
+end
--- a/vendors/ligo-utils/simple-utils/wrap.ml
+++ b/vendors/ligo-utils/simple-utils/wrap.ml
@ -0,0 +1,21 @@
+module Make (P : sig type meta end) = struct
+  type meta = P.meta
+  type 'value t = {
+    value : 'value ;
+    meta : meta ;
+  }
+
+  let make meta value = { value ; meta }
+  let value t = t.value
+  let meta t = t.meta
+
+  let apply : ('a -> 'b) -> 'a t -> 'b = fun f x -> f x.value
+end
+
+module Location = struct
+  include Make(struct type meta = Location.t end)
+
+  let make_f f : loc:_ -> _ -> _ t = fun ~loc x ->  make loc (f x)
+  let make ~loc x : _ t = make loc x
+  let update_location ~loc t = {t with meta = loc}
+end
--- a/vendors/ligo-utils/simple-utils/x_list.ml
+++ b/vendors/ligo-utils/simple-utils/x_list.ml
@ -0,0 +1,165 @@
+include List
+
+let rec remove n = function
+  | [] -> raise (Failure "List.remove")
+  | _  :: tl when n = 0 -> tl
+  | hd :: tl -> hd :: remove (n - 1) tl
+
+
+let map ?(acc = []) f lst =
+  let rec aux acc f = function
+    | [] -> acc
+    | hd :: tl -> aux (f hd :: acc) f tl
+  in
+  aux acc f (List.rev lst)
+
+let fold_map_right : type acc ele ret . (acc -> ele -> (acc * ret)) -> acc -> ele list -> ret list =
+  fun f acc lst ->
+  let rec aux (acc , prev) f = function
+    | [] -> (acc , prev)
+    | hd :: tl ->
+        let (acc' , hd') = f acc hd in
+        aux (acc' , hd' :: prev) f tl
+  in
+  snd @@ aux (acc , []) f (List.rev lst)
+
+let fold_map : type acc ele ret . (acc -> ele -> (acc * ret)) -> acc -> ele list -> ret list =
+  fun f acc lst ->
+  let rec aux (acc , prev) f = function
+    | [] -> (acc , prev)
+    | hd :: tl ->
+        let (acc' , hd') = f acc hd in
+        aux (acc' , hd' :: prev) f tl
+  in
+  List.rev @@ snd @@ aux (acc , []) f lst
+
+let fold_right' f init lst = List.fold_left f init (List.rev lst)
+
+let rec remove_element x lst =
+  match lst with
+  | [] -> raise (Failure "X_list.remove_element")
+  | hd :: tl when x = hd -> tl
+  | hd :: tl -> hd :: remove_element x tl
+
+let filter_map f =
+  let rec aux acc lst = match lst with
+    | [] -> List.rev acc
+    | hd :: tl -> aux (
+        match f hd with
+        | Some x -> x :: acc
+        | None -> acc
+      ) tl
+  in
+  aux []
+
+let cons_iter = fun fhd ftl lst ->
+  match lst with
+  | [] -> ()
+  | hd :: tl -> fhd hd ; List.iter ftl tl
+
+let range n =
+  let rec aux acc n =
+    if n = 0
+    then acc
+    else aux ((n-1) :: acc) (n-1)
+  in
+  aux [] n
+
+let find_map f lst =
+  let rec aux = function
+    | [] -> None
+    | hd::tl -> (
+      match f hd with
+      | Some _ as s -> s
+      | None -> aux tl
+    )
+  in
+  aux lst
+
+let find_index f lst =
+  let rec aux n = function
+  | [] -> raise (Failure "find_index")
+  | hd :: _ when f hd -> n
+  | _ :: tl -> aux (n + 1) tl in
+  aux 0 lst
+
+let find_full f lst =
+  let rec aux n = function
+  | [] -> raise (Failure "find_index")
+  | hd :: _ when f hd -> (hd, n)
+  | _ :: tl -> aux (n + 1) tl in
+  aux 0 lst
+
+let assoc_i x lst =
+  let rec aux n = function
+    | [] -> raise (Failure "List:assoc_i")
+    | (x', y) :: _ when x = x' -> (y, n)
+    | _ :: tl -> aux (n + 1) tl
+  in
+  aux 0 lst
+
+let rec from n lst =
+  if n = 0
+  then lst
+  else from (n - 1) (tl lst)
+
+let until n lst =
+  let rec aux acc n lst =
+    if n = 0
+    then acc
+    else aux ((hd lst) :: acc) (n - 1) (tl lst)
+  in
+  rev (aux [] n lst)
+
+let uncons_opt = function
+  | [] -> None
+  | hd :: tl -> Some (hd, tl)
+
+let rev_uncons_opt = function
+  | [] -> None
+  | lst ->
+      let r = rev lst in
+      let last = hd r in
+      let hds = rev @@ tl r in
+      Some (hds , last)
+
+let hds lst = match rev_uncons_opt lst with
+  | None -> failwith "toto"
+  | Some (hds , _) -> hds
+
+let to_pair = function
+  | [a ; b] -> Some (a , b)
+  | _ -> None
+
+let to_singleton = function
+  | [a] -> Some a
+  | _ -> None
+
+module Ne = struct
+
+  type 'a t = 'a * 'a list
+
+  let of_list lst = List.(hd lst, tl lst)
+  let to_list (hd, tl : _ t) = hd :: tl
+  let singleton hd : 'a t = hd , []
+  let hd : 'a t -> 'a = fst
+  let cons : 'a -> 'a t -> 'a t = fun hd' (hd , tl) -> hd' , hd :: tl
+  let iter f (hd, tl : _ t) = f hd ; List.iter f tl
+  let map f (hd, tl : _ t) = f hd, List.map f tl
+  let hd_map : _ -> 'a t -> 'a t = fun f (hd , tl) -> (f hd , tl)
+  let mapi f (hd, tl : _ t) =
+    let lst = List.mapi f (hd::tl) in
+    of_list lst
+  let concat (hd, tl : _ t) = hd @ List.concat tl
+  let rev (hd, tl : _ t) =
+    match tl with
+    | [] -> (hd, [])
+    | lst ->
+        let r = List.rev lst in
+        (List.hd r, List.tl r @ [hd])
+  let find_map = fun f (hd , tl : _ t) ->
+    match f hd with
+    | Some x -> Some x
+    | None -> find_map f tl
+
+end
--- a/vendors/ligo-utils/simple-utils/x_map.ml
+++ b/vendors/ligo-utils/simple-utils/x_map.ml
@ -0,0 +1,27 @@
+module type OrderedType = Map.OrderedType
+
+module type S = sig
+  include Map.S
+
+  val of_list : (key * 'a) list -> 'a t
+  val to_list : 'a t -> 'a list
+  val to_kv_list : 'a t -> (key * 'a) list
+end
+
+module Make(Ord : Map.OrderedType) : S with type key = Ord.t = struct
+  include Map.Make(Ord)
+
+  let of_list (lst: (key * 'a) list) : 'a t =
+    let aux prev (k, v) = add k v prev in
+    List.fold_left aux empty lst
+
+  let to_list (t: 'a t) : 'a list =
+    let aux _k v prev = v :: prev in
+    fold aux t []
+
+  let to_kv_list (t: 'a t) : (key * 'a) list =
+    let aux k v prev = (k, v) :: prev in
+    fold aux t []
+end
+
+module String = Make(String)
--- a/vendors/ligo-utils/simple-utils/x_option.ml
+++ b/vendors/ligo-utils/simple-utils/x_option.ml
@ -0,0 +1,59 @@
+let (>>=) x f = match x with
+  | None -> None
+  | Some x -> f x
+
+let first_some = fun a b -> match (a , b) with
+  | Some a , _ -> Some a
+  | _ , Some b -> Some b
+  | _ -> None
+
+let unopt ~default x = match x with
+  | None -> default
+  | Some x -> x
+
+let unopt_exn x = match x with
+  | None -> raise Not_found
+  | Some x -> x
+
+let map ~f x = match x with
+  | Some x -> Some (f x)
+  | None -> None
+
+let lr (a , b) = match (a , b) with
+  | Some x , _ -> Some (`Left x)
+  | None , Some x -> Some (`Right x)
+  | _ -> None
+
+(* TODO: recursive terminal *)
+let rec bind_list = fun lst ->
+  match lst with
+  | [] -> Some []
+  | hd :: tl -> (
+      match hd with
+      | None -> None
+      | Some hd' -> (
+          match bind_list tl with
+          | None -> None
+          | Some tl' -> Some (hd' :: tl')
+        )
+    )
+
+
+let bind_pair = fun (a , b) ->
+  a >>= fun a' ->
+  b >>= fun b' ->
+  Some (a' , b')
+
+let bind_map_list = fun f lst -> bind_list (X_list.map f lst)
+
+let bind_map_pair = fun f (a , b) -> bind_pair (f a , f b)
+
+let bind_smap (s:_ X_map.String.t) =
+  let open X_map.String in
+  let aux k v prev =
+    prev >>= fun prev' ->
+    v >>= fun v' ->
+    Some (add k v' prev') in
+  fold aux s (Some empty)
+
+let bind_map_smap f smap = bind_smap (X_map.String.map f smap)
--- a/vendors/ligo-utils/tezos-utils/dune
+++ b/vendors/ligo-utils/tezos-utils/dune
@ -0,0 +1,12 @@
+(library
+  (name tezos_utils)
+  (public_name tezos-utils)
+  (libraries
+    tezos-error-monad
+    tezos-stdlib-unix
+    tezos-memory-proto-alpha
+    simple-utils
+    michelson-parser
+  )
+ (flags (:standard -open Simple_utils ))
+)
--- a/vendors/ligo-utils/tezos-utils/dune-project
+++ b/vendors/ligo-utils/tezos-utils/dune-project
@ -0,0 +1 @@
+(lang dune 1.6)
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/dune
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/dune
@ -0,0 +1,10 @@
+(library
+ (name michelson_parser)
+ (public_name michelson-parser)
+ (libraries
+  tezos-base
+  tezos-memory-proto-alpha
+ )
+ (flags (:standard -w -9-32 -safe-string
+          -open Tezos_base__TzPervasives
+)))
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/dune-project
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/dune-project
@ -0,0 +1 @@
+(lang dune 1.6)
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/michelson-parser.opam
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/michelson-parser.opam
@ -0,0 +1,16 @@
+name: "michelson-parser"
+opam-version: "2.0"
+maintainer: "ligolang@gmail.com"
+authors: [ "Galfour" ]
+homepage: "https://gitlab.com/ligolang/tezos"
+bug-reports: "https://gitlab.com/ligolang/tezos/issues"
+dev-repo: "git+https://gitlab.com/ligolang/tezos.git"
+license: "MIT"
+depends: [
+  "ocamlfind" { build }
+  "dune"
+  "tezos-memory-proto-alpha"
+]
+build: [
+  [ "dune" "build" "-p" name "-j" jobs ]
+]
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/michelson_v1_macros.ml
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/michelson_v1_macros.ml
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/michelson_v1_macros.mli
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/michelson_v1_macros.mli
@ -0,0 +1,62 @@
+(*****************************************************************************)
+(*                                                                           *)
+(* Open Source License                                                       *)
+(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
+(*                                                                           *)
+(* Permission is hereby granted, free of charge, to any person obtaining a   *)
+(* copy of this software and associated documentation files (the "Software"),*)
+(* to deal in the Software without restriction, including without limitation *)
+(* the rights to use, copy, modify, merge, publish, distribute, sublicense,  *)
+(* and/or sell copies of the Software, and to permit persons to whom the     *)
+(* Software is furnished to do so, subject to the following conditions:      *)
+(*                                                                           *)
+(* The above copyright notice and this permission notice shall be included   *)
+(* in all copies or substantial portions of the Software.                    *)
+(*                                                                           *)
+(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
+(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
+(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL   *)
+(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
+(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING   *)
+(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER       *)
+(* DEALINGS IN THE SOFTWARE.                                                 *)
+(*                                                                           *)
+(*****************************************************************************)
+
+open Tezos_micheline
+
+type 'l node = ('l, string) Micheline.node
+
+type error += Unexpected_macro_annotation of string
+type error += Sequence_expected of string
+type error += Invalid_arity of string * int * int
+
+val expand : 'l node -> 'l node tzresult
+val expand_rec : 'l node -> 'l node * error list
+
+val expand_caddadr : 'l node -> 'l node option tzresult
+val expand_set_caddadr : 'l node -> 'l node option tzresult
+val expand_map_caddadr : 'l node -> 'l node option tzresult
+val expand_dxiiivp : 'l node -> 'l node option tzresult
+val expand_pappaiir : 'l node -> 'l node option tzresult
+val expand_duuuuup : 'l node -> 'l node option tzresult
+val expand_compare : 'l node -> 'l node option tzresult
+val expand_asserts : 'l node -> 'l node option tzresult
+val expand_unpappaiir : 'l node -> 'l node option tzresult
+val expand_if_some : 'l node -> 'l node option tzresult
+val expand_if_right : 'l node -> 'l node option tzresult
+
+val unexpand : 'l node -> 'l node
+val unexpand_rec : 'l node -> 'l node
+
+val unexpand_caddadr : 'l node -> 'l node option
+val unexpand_set_caddadr : 'l node -> 'l node option
+val unexpand_map_caddadr : 'l node -> 'l node option
+val unexpand_dxiiivp : 'l node -> 'l node option
+val unexpand_pappaiir : 'l node -> 'l node option
+val unexpand_duuuuup : 'l node -> 'l node option
+val unexpand_compare : 'l node -> 'l node option
+val unexpand_asserts : 'l node -> 'l node option
+val unexpand_unpappaiir : 'l node -> 'l node option
+val unexpand_if_some : 'l node -> 'l node option
+val unexpand_if_right : 'l node -> 'l node option
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/v1.ml
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/v1.ml
@ -0,0 +1,91 @@
+(*****************************************************************************)
+(*                                                                           *)
+(* Open Source License                                                       *)
+(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
+(*                                                                           *)
+(* Permission is hereby granted, free of charge, to any person obtaining a   *)
+(* copy of this software and associated documentation files (the "Software"),*)
+(* to deal in the Software without restriction, including without limitation *)
+(* the rights to use, copy, modify, merge, publish, distribute, sublicense,  *)
+(* and/or sell copies of the Software, and to permit persons to whom the     *)
+(* Software is furnished to do so, subject to the following conditions:      *)
+(*                                                                           *)
+(* The above copyright notice and this permission notice shall be included   *)
+(* in all copies or substantial portions of the Software.                    *)
+(*                                                                           *)
+(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
+(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
+(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL   *)
+(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
+(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING   *)
+(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER       *)
+(* DEALINGS IN THE SOFTWARE.                                                 *)
+(*                                                                           *)
+(*****************************************************************************)
+
+open Memory_proto_alpha
+open Tezos_micheline
+open Micheline_parser
+open Micheline
+
+type parsed =
+  { source : string ;
+    unexpanded : string canonical ;
+    expanded : Michelson_v1_primitives.prim canonical ;
+    expansion_table : (int * (Micheline_parser.location * int list)) list ;
+    unexpansion_table : (int * int) list }
+
+(* Unexpanded toplevel expression should be a sequence *)
+let expand_all source ast errors =
+  let unexpanded, loc_table =
+    extract_locations ast in
+  let expanded, expansion_errors =
+    Michelson_v1_macros.expand_rec (root unexpanded) in
+  let expanded, unexpansion_table =
+    extract_locations expanded in
+  let expansion_table =
+    let sorted =
+      List.sort (fun (_, a) (_, b) -> compare a b) unexpansion_table in
+    let grouped =
+      let rec group = function
+        | acc, [] -> acc
+        | [], (u, e) :: r ->
+            group ([ (e, [ u ]) ], r)
+        | ((pe, us) :: racc as acc), (u, e) :: r ->
+            if e = pe then
+              group (((e, u :: us) :: racc), r)
+            else
+              group (((e, [ u ]) :: acc), r) in
+      group ([], sorted) in
+    List.map2
+      (fun (l, ploc) (l', elocs) ->
+         assert (l = l') ;
+         (l, (ploc, elocs)))
+      (List.sort compare loc_table)
+      (List.sort compare grouped) in
+  match Alpha_environment.wrap_error (Michelson_v1_primitives.prims_of_strings expanded) with
+  | Ok expanded ->
+      { source ; unexpanded ; expanded ;
+        expansion_table ; unexpansion_table },
+      errors @ expansion_errors
+  | Error errs ->
+      { source ; unexpanded ;
+        expanded = Micheline.strip_locations (Seq ((), [])) ;
+        expansion_table ; unexpansion_table },
+      errors @ expansion_errors @ errs
+
+let parse_toplevel ?check source =
+  let tokens, lexing_errors = Micheline_parser.tokenize source in
+  let asts, parsing_errors = Micheline_parser.parse_toplevel ?check tokens in
+  let ast =
+    let start = min_point asts and stop = max_point asts in
+    Seq ({ start ; stop }, asts) in
+  expand_all source ast (lexing_errors @ parsing_errors)
+
+let parse_expression ?check source =
+  let tokens, lexing_errors = Micheline_parser.tokenize source in
+  let ast, parsing_errors = Micheline_parser.parse_expression ?check tokens in
+  expand_all source ast (lexing_errors @ parsing_errors)
+
+let expand_all ~source ~original =
+  expand_all source original []
--- a/vendors/ligo-utils/tezos-utils/michelson-parser/v1.mli
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/v1.mli
@ -0,0 +1,51 @@
+(*****************************************************************************)
+(*                                                                           *)
+(* Open Source License                                                       *)
+(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
+(*                                                                           *)
+(* Permission is hereby granted, free of charge, to any person obtaining a   *)
+(* copy of this software and associated documentation files (the "Software"),*)
+(* to deal in the Software without restriction, including without limitation *)
+(* the rights to use, copy, modify, merge, publish, distribute, sublicense,  *)
+(* and/or sell copies of the Software, and to permit persons to whom the     *)
+(* Software is furnished to do so, subject to the following conditions:      *)
+(*                                                                           *)
+(* The above copyright notice and this permission notice shall be included   *)
+(* in all copies or substantial portions of the Software.                    *)
+(*                                                                           *)
+(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
+(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
+(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL   *)
+(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
+(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING   *)
+(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER       *)
+(* DEALINGS IN THE SOFTWARE.                                                 *)
+(*                                                                           *)
+(*****************************************************************************)
+
+open Memory_proto_alpha
+open Alpha_context
+
+open Tezos_micheline
+
+(** The result of parsing and expanding a Michelson V1 script or data. *)
+type parsed =
+  {
+    source : string ;
+    (** The original source code. *)
+    unexpanded : string Micheline.canonical ;
+    (** Original expression with macros. *)
+    expanded : Script.expr ;
+    (** Expression with macros fully expanded. *)
+    expansion_table :
+      (int * (Micheline_parser.location * int list)) list ;
+    (** Associates unexpanded nodes to their parsing locations and
+        the nodes expanded from it in the expanded expression. *)
+    unexpansion_table : (int * int) list ;
+    (** Associates an expanded node to its source in the unexpanded
+        expression. *)
+  }
+
+val parse_toplevel : ?check:bool -> string -> parsed Micheline_parser.parsing_result
+val parse_expression : ?check:bool -> string -> parsed Micheline_parser.parsing_result
+val expand_all : source:string -> original:Micheline_parser.node -> parsed Micheline_parser.parsing_result
--- a/vendors/ligo-utils/tezos-utils/tezos-utils.opam
+++ b/vendors/ligo-utils/tezos-utils/tezos-utils.opam
@ -0,0 +1,51 @@
+opam-version: "2.0"
+name: "tezos-utils"
+version: "dev"
+synopsis: "LIGO Tezos specific Utilities, to be used by other libraries"
+maintainer: "Galfour <ligolang@gmail.com>"
+authors: "Galfour <ligolang@gmail.com>"
+license: "MIT"
+homepage: "https://gitlab.com/ligolang/ligo-utils"
+bug-reports: "https://gitlab.com/ligolang/ligo-utils/issues"
+depends: [
+  "dune"
+  "base"
+  "base"
+  "bigstring"
+  "calendar"
+  "cohttp-lwt-unix"
+  "cstruct"
+  "ezjsonm"
+  "hex"
+  "hidapi"
+  "ipaddr"
+  "irmin"
+  "js_of_ocaml"
+  "lwt"
+  "lwt_log"
+  "mtime"
+  "ocplib-endian"
+  "ocp-ocamlres"
+  "re"
+  "rresult"
+  "stdio"
+  "uri"
+  "uutf"
+  "zarith"
+  "ocplib-json-typed"
+  "ocplib-json-typed-bson"
+  "tezos-crypto"
+  "tezos-stdlib-unix"
+  "tezos-data-encoding"
+  "tezos-protocol-environment"
+  "tezos-protocol-alpha"
+  "michelson-parser"
+  "simple-utils"
+  # from ppx_let:
+  "ocaml" {>= "4.04.2" & < "4.08.0"}
+  "dune"   {build & >= "1.5.1"}
+  "ppxlib" {>= "0.5.0"}
+]
+build: [
+  ["dune" "build" "-p" name]
+]
--- a/vendors/ligo-utils/tezos-utils/tezos_utils.ml
+++ b/vendors/ligo-utils/tezos-utils/tezos_utils.ml
@ -0,0 +1,8 @@
+module Stdlib_unix = Tezos_stdlib_unix
+module Data_encoding = Tezos_data_encoding
+module Crypto = Tezos_crypto
+module Signature = Tezos_base.TzPervasives.Signature
+module Time = Tezos_base.TzPervasives.Time
+module Micheline = Tezos_micheline
+module Michelson = X_michelson
+module Error_monad = X_error_monad
--- a/vendors/ligo-utils/tezos-utils/x_error_monad.ml
+++ b/vendors/ligo-utils/tezos-utils/x_error_monad.ml
@ -0,0 +1,25 @@
+module Error_monad = Tezos_error_monad.Error_monad
+
+let to_string err =
+  let json = Error_monad.json_of_error err in
+  Tezos_data_encoding.Json.to_string json
+
+let print err =
+  Format.printf "%s\n" @@ to_string err
+
+let force_ok ?(msg = "") = function
+  | Ok x -> x
+  | Error errs ->
+    Format.printf "Errors :\n";
+    List.iter print errs ;
+    raise @@ Failure ("force_ok : " ^ msg)
+
+let is_ok = function
+  | Ok _ -> true
+  | Error _ -> false
+
+let force_ok_str ?(msg = "") = function
+  | Ok x -> x
+  | Error err ->
+    Format.printf "Error : %s\n" err;
+    raise @@ Failure ("force_ok : " ^ msg)
--- a/vendors/ligo-utils/tezos-utils/x_michelson.ml
+++ b/vendors/ligo-utils/tezos-utils/x_michelson.ml
@ -0,0 +1,94 @@
+open Tezos_micheline
+open Micheline
+
+include Michelson_primitives
+
+type michelson = (int, prim) node
+type t = michelson
+
+let prim ?(annot=[]) ?(children=[]) p : michelson =
+  Prim (0, p, children, annot)
+
+let annotate annot = function
+  | Prim (l, p, c, []) -> Prim (l, p, c, [annot])
+  | _ -> raise (Failure "annotate")
+
+let seq s : michelson = Seq (0, s)
+
+let i_comment s : michelson = prim ~annot:["\"" ^ s ^ "\""] I_NOP
+
+let contract parameter storage code =
+  seq [
+    prim ~children:[parameter] K_parameter ;
+    prim ~children:[storage] K_storage ;
+    prim ~children:[code] K_code ;
+  ]
+
+let int n : michelson = Int (0, n)
+let string s : michelson = String (0, s)
+let bytes s : michelson = Bytes (0, s)
+
+let t_unit = prim T_unit
+let t_string = prim T_string
+let t_pair a b = prim ~children:[a;b] T_pair
+let t_lambda a b = prim ~children:[a;b] T_lambda
+
+let d_unit = prim D_Unit
+let d_pair a b = prim ~children:[a;b] D_Pair
+
+let i_dup = prim I_DUP
+let i_car = prim I_CAR
+let i_cdr = prim I_CDR
+let i_pair = prim I_PAIR
+let i_swap = prim I_SWAP
+let i_piar = seq [ i_swap ; i_pair ]
+let i_push ty code = prim ~children:[ty;code] I_PUSH
+let i_push_unit = i_push t_unit d_unit
+let i_push_string str = i_push t_string (string str)
+let i_none ty = prim ~children:[ty] I_NONE
+let i_nil ty = prim ~children:[ty] I_NIL
+let i_some = prim I_SOME
+let i_lambda arg ret body = prim ~children:[arg;ret;body] I_LAMBDA
+let i_empty_map src dst = prim ~children:[src;dst] I_EMPTY_MAP
+let i_drop = prim I_DROP
+let i_exec = prim I_EXEC
+
+let i_if a b = prim ~children:[seq [a] ; seq[b]] I_IF
+let i_if_none a b = prim ~children:[seq [a] ; seq[b]] I_IF_NONE
+let i_if_left a b = prim ~children:[seq [a] ; seq[b]] I_IF_LEFT
+let i_failwith = prim I_FAILWITH
+let i_assert_some = i_if_none (seq [i_push_string "ASSERT_SOME" ; i_failwith]) (seq [])
+let i_assert_some_msg msg = i_if_none (seq [msg ; i_failwith]) (seq [])
+
+let dip code : michelson = prim ~children:[seq [code]] I_DIP
+let i_unpair = seq [i_dup ; i_car ; dip i_cdr]
+let i_unpiar = seq [i_dup ; i_cdr ; dip i_car]
+
+let rec strip_annots : michelson -> michelson = function
+  | Seq(l, s) -> Seq(l, List.map strip_annots s)
+  | Prim (l, p, lst, _) -> Prim (l, p, List.map strip_annots lst, [])
+  | x -> x
+
+let rec strip_nops : michelson -> michelson = function
+  | Seq(l, s) -> Seq(l, List.map strip_nops s)
+  | Prim (l, I_NOP, _, _) -> Seq (l, [])
+  | Prim (l, p, lst, a) -> Prim (l, p, List.map strip_nops lst, a)
+  | x -> x
+
+let pp ppf (michelson:michelson) =
+  let open Micheline_printer in
+  let canonical = strip_locations michelson in
+  let node = printable string_of_prim canonical in
+  print_expr ppf node
+
+let pp_stripped ppf (michelson:michelson) =
+  let open Micheline_printer in
+  let michelson' = strip_nops @@ strip_annots michelson in
+  let canonical = strip_locations michelson' in
+  let node = printable string_of_prim canonical in
+  print_expr ppf node
+
+let pp_naked ppf m =
+  let naked = strip_annots m in
+  pp ppf naked
+
				`@ -0,0 +1 @@`
				`(executables (names test) (preprocess (pps ppx_let_generalized)))`