%{
(* START HEADER *)

[@@@warning "-42"]

open Region
open AST

(* END HEADER *)
%}

(* See [ParToken.mly] for the definition of tokens. *)

(* Entry points *)

%start contract interactive_expr
%type <AST.t> contract
%type <AST.expr> interactive_expr

%%

(* RULES *)

(* The rule [series(Item,TERM)] parses a non-empty list of [Item]
   separated by semicolons and optionally terminated by a semicolon,
   then the terminal TERM. *)

series(Item,TERM):
  Item after_item(Item,TERM) { $1,$2 }

after_item(Item,TERM):
  SEMI item_or_closing(Item,TERM) {
    match $2 with
      `Some (item, items, term, closing) ->
        ($1, item)::items, term, closing
    | `Closing closing ->
        [], Some $1, closing
  }
| TERM {
   [], None, $1
  }

item_or_closing(Item,TERM):
  TERM {
   `Closing $1
  }
| series(Item,TERM) {
    let item, (items, term, closing) = $1
    in `Some (item, items, term, closing)
  }

(* Compound constructs *)

par(X):
  LPAR X RPAR {
    let region = cover $1 $3
    and value  = {
      lpar   = $1;
      inside = $2;
      rpar   = $3}
    in {region; value}
  }

brackets(X):
  LBRACKET X RBRACKET {
    let region = cover $1 $3
    and value  = {
      lbracket = $1;
      inside   = $2;
      rbracket = $3}
    in {region; value}
  }

(* Sequences

   Series of instances of the same syntactical category have often to
   be parsed, like lists of expressions, patterns etc. The simplest of
   all is the possibly empty sequence (series), parsed below by
   [seq]. The non-empty sequence is parsed by [nseq]. Note that the
   latter returns a pair made of the first parsed item (the parameter
   [X]) and the rest of the sequence (possibly empty). This way, the
   OCaml typechecker can keep track of this information along the
   static control-flow graph. The rule [sepseq] parses possibly empty
   sequences of items separated by some token (e.g., a comma), and
   rule [nsepseq] is for non-empty such sequences. See module [Utils]
   for the types corresponding to the semantic actions of those rules.
 *)

(* Possibly empty sequence of items *)

seq(X):
  (**)     {     [] }
| X seq(X) { $1::$2 }

(* Non-empty sequence of items *)

nseq(X):
  X seq(X) { $1,$2 }

(* Non-empty separated sequence of items *)

nsepseq(X,Sep):
  X                    {                 $1,        [] }
| X Sep nsepseq(X,Sep) { let h,t = $3 in $1, ($2,h)::t }

(* Possibly empy separated sequence of items *)

sepseq(X,Sep):
  (**)           {    None }
| nsepseq(X,Sep) { Some $1 }

(* TODO *)
(*
sequence(Item,TERM):
  nsepseq(Item,TERM)      {}
| nseq(Item TERM {$1,$2}) {}
 *)

(* Inlines *)

%inline var         : Ident { $1 }
%inline type_name   : Ident { $1 }
%inline fun_name    : Ident { $1 }
%inline field_name  : Ident { $1 }
%inline struct_name : Ident { $1 }

(* Main *)

contract:
  nseq(declaration) EOF {
    {decl = $1; eof = $2}
  }

declaration:
  type_decl   {    TypeDecl $1 }
| const_decl  {   ConstDecl $1 }
| lambda_decl {  LambdaDecl $1 }

(* Type declarations *)

type_decl:
  Type type_name Is type_expr option(SEMI) {
    let stop =
      match $5 with
        Some region -> region
      |        None -> type_expr_to_region $4 in
    let region = cover $1 stop in
    let value = {
      kwd_type   = $1;
      name       = $2;
      kwd_is     = $3;
      type_expr  = $4;
      terminator = $5}
    in {region; value}}

type_expr:
  cartesian   {   TProd $1 }
| sum_type    {    TSum $1 }
| record_type { TRecord $1 }

cartesian:
  nsepseq(function_type,TIMES) {
    let region = nsepseq_to_region type_expr_to_region $1
    in {region; value=$1}}

function_type:
  core_type {
    $1
  }
| core_type ARROW function_type {
    let region = cover (type_expr_to_region $1)
                       (type_expr_to_region $3)
    in TFun {region; value = ($1, $2, $3)} }

core_type:
  type_name {
    TAlias $1
  }
| type_name type_tuple {
    let region = cover $1.region $2.region
    in TApp {region; value = $1,$2}
  }
| Map type_tuple {
    let region = cover $1 $2.region in
    let type_constr = {value="map"; region=$1}
    in TApp {region; value = type_constr, $2}
  }
| Set par(type_expr) {
    let total = cover $1 $2.region in
    let type_constr = {value="set"; region=$1} in
    let {region; value = {lpar; inside; rpar}} = $2 in
    let tuple = {region; value={lpar; inside=inside,[]; rpar}}
    in TApp {region=total; value = type_constr, tuple}
  }
| List par(type_expr) {
    let total = cover $1 $2.region in
    let type_constr = {value="list"; region=$1} in
    let {region; value = {lpar; inside; rpar}} = $2 in
    let tuple = {region; value={lpar; inside=inside,[]; rpar}}
    in TApp {region=total; value = type_constr, tuple}
  }
| par(type_expr) {
    TPar $1}

type_tuple:
  par(nsepseq(type_expr,COMMA)) { $1 }

sum_type:
  option(VBAR) nsepseq(variant,VBAR) {
    let region = nsepseq_to_region (fun x -> x.region) $2
    in {region; value = $2} }

variant:
  Constr Of cartesian {
    let region = cover $1.region $3.region
    and value = {constr = $1; kwd_of = $2; product = $3}
    in {region; value} }
  (* TODO: Unary constructors *)

record_type:
  Record series(field_decl,End) {
   let first, (others, terminator, closing) = $2 in
   let region = cover $1 closing
   and value  = {
     opening = Kwd $1;
     elements = Some (first, others);
     terminator;
     closing = End closing}
   in {region; value}
  }
| Record LBRACKET series(field_decl,RBRACKET) {
   let first, (others, terminator, closing) = $3 in
   let region = cover $1 closing
   and value  = {
     opening = KwdBracket ($1,$2);
     elements = Some (first, others);
     terminator;
     closing = RBracket closing}
   in {region; value} }

field_decl:
  field_name COLON type_expr {
    let stop   = type_expr_to_region $3 in
    let region = cover $1.region stop
    and value  = {field_name = $1; colon = $2; field_type = $3}
    in {region; value} }

(* Function and procedure declarations *)

lambda_decl:
  fun_decl   {   FunDecl $1 }
| proc_decl  {  ProcDecl $1 }
| entry_decl { EntryDecl $1 }

fun_decl:
  Function fun_name parameters COLON type_expr Is
    seq(local_decl)
    block
  With expr option(SEMI) {
    let stop =
      match $11 with
        Some region -> region
      |        None -> expr_to_region $10 in
    let region = cover $1 stop
    and value = {
      kwd_function = $1;
      name         = $2;
      param        = $3;
      colon        = $4;
      ret_type     = $5;
      kwd_is       = $6;
      local_decls  = $7;
      block        = $8;
      kwd_with     = $9;
      return       = $10;
      terminator   = $11}
    in {region; value}}

entry_decl:
  Entrypoint fun_name entry_params COLON type_expr Is
    seq(local_decl)
    block
  With expr option(SEMI) {
    let stop =
      match $11 with
        Some region -> region
      |        None -> expr_to_region $10 in
    let region = cover $1 stop
    and value = {
      kwd_entrypoint = $1;
      name           = $2;
      param          = $3;
      colon          = $4;
      ret_type       = $5;
      kwd_is         = $6;
      local_decls    = $7;
      block          = $8;
      kwd_with       = $9;
      return         = $10;
      terminator     = $11}
    in {region; value}}

entry_params:
  par(nsepseq(entry_param_decl,SEMI)) { $1 }

proc_decl:
  Procedure fun_name parameters Is
    seq(local_decl)
    block option(SEMI)
    {
     let stop =
       match $7 with
         Some region -> region
       |        None -> $6.region in
     let region = cover $1 stop
     and value = {
       kwd_procedure = $1;
       name          = $2;
       param         = $3;
       kwd_is        = $4;
       local_decls   = $5;
       block         = $6;
       terminator    = $7}
     in {region; value}}

parameters:
  par(nsepseq(param_decl,SEMI)) { $1 }

param_decl:
  Var var COLON param_type {
    let stop   = type_expr_to_region $4 in
    let region = cover $1 stop
    and value  = {
      kwd_var    = $1;
      var        = $2;
      colon      = $3;
      param_type = $4}
    in ParamVar {region; value}
  }
| Const var COLON param_type {
    let stop   = type_expr_to_region $4 in
    let region = cover $1 stop
    and value  = {
      kwd_const  = $1;
      var        = $2;
      colon      = $3;
      param_type = $4}
    in ParamConst {region; value}}

entry_param_decl:
  param_decl {
    match $1 with
      ParamConst const -> EntryConst const
    | ParamVar     var -> EntryVar   var
  }
| Storage var COLON param_type {
    let stop   = type_expr_to_region $4 in
    let region = cover $1 stop
    and value  = {
      kwd_storage  = $1;
      var          = $2;
      colon        = $3;
      storage_type = $4}
    in EntryStore {region; value}}

param_type:
  cartesian { TProd $1 }

block:
(*  Begin sequence(statement,SEMI) End { failwith "TODO" } *)
  Begin series(statement,End) {
   let first, (others, terminator, closing) = $2 in
   let region = cover $1 closing
   and value = {
     opening    = Begin $1;
     statements = first, others;
     terminator;
     closing    = End closing}
   in {region; value}
  }
| Block LBRACE series(statement,RBRACE) {
   let first, (others, terminator, closing) = $3 in
   let region = cover $1 closing
   and value = {
     opening    = Block ($1,$2);
     statements = first, others;
     terminator;
     closing    = Block closing}
   in {region; value}}

statement:
  instruction     { Instr $1 }
| open_data_decl  { Data  $1 }

open_data_decl:
  open_const_decl { LocalConst $1 }
| open_var_decl   { LocalVar   $1 }

open_const_decl:
  Const unqualified_decl(EQUAL) {
    let name, colon, const_type, equal, init, stop = $2 in
    let region = cover $1 stop
    and value = {
      kwd_const = $1;
      name;
      colon;
      const_type;
      equal;
      init;
      terminator = None}
    in {region; value}}

open_var_decl:
  Var unqualified_decl(ASS) {
    let name, colon, var_type, assign, init, stop = $2 in
    let region = cover $1 stop
    and value = {
      kwd_var = $1;
      name;
      colon;
      var_type;
      assign;
      init;
      terminator = None}
    in {region; value}}

local_decl:
  lambda_decl { LocalLam  $1 }
| data_decl   { LocalData $1 }

data_decl:
  const_decl { LocalConst $1 }
| var_decl   { LocalVar   $1 }

unqualified_decl(OP):
  var COLON type_expr OP extended_expr {
    let init, region =
      match $5 with
        `Expr e -> e, expr_to_region e
      | `EList kwd_nil ->
           EList (Nil kwd_nil), kwd_nil
      | `ENone region ->
           EConstr (NoneExpr region), region
    in $1, $2, $3, $4, init, region}

const_decl:
  open_const_decl SEMI {
    let const_decl : AST.const_decl = $1.value in
    {$1 with value = {const_decl with terminator = Some $2}}
  }
| open_const_decl { $1 }

var_decl:
  open_var_decl SEMI {
    let var_decl : AST.var_decl = $1.value in
    {$1 with value = {var_decl with terminator = Some $2}}
  }
| open_var_decl { $1 }

extended_expr:
  expr   { `Expr  $1 }

instruction:
  single_instr { Single $1 }
| block        { Block  $1 : instruction }

single_instr:
  conditional  {        Cond $1 }
| case_instr   {   CaseInstr $1 }
| assignment   {      Assign $1 }
| loop         {        Loop $1 }
| proc_call    {    ProcCall $1 }
| fail_instr   {        Fail $1 }
| Skip         {        Skip $1 }
| record_patch { RecordPatch $1 }
| map_patch    {    MapPatch $1 }
| set_patch    {    SetPatch $1 }
| map_remove   {   MapRemove $1 }
| set_remove   {   SetRemove $1 }

set_remove:
  Remove expr From Set path {
    let region = cover $1 (path_to_region $5) in
    let value  = {
      kwd_remove = $1;
      element    = $2;
      kwd_from   = $3;
      kwd_set    = $4;
      set        = $5}
    in {region; value}}

map_remove:
  Remove expr From Map path {
    let region = cover $1 (path_to_region $5) in
    let value  = {
      kwd_remove = $1;
      key        = $2;
      kwd_from   = $3;
      kwd_map    = $4;
      map        = $5}
    in {region; value}}

set_patch:
  Patch path With injection(Set,expr) {
    let region = cover $1 $4.region in
    let value  = {
      kwd_patch = $1;
      path      = $2;
      kwd_with  = $3;
      set_inj   = $4}
    in {region; value}}

map_patch:
  Patch path With map_injection {
    let region = cover $1 $4.region in
    let value  = {
      kwd_patch = $1;
      path      = $2;
      kwd_with  = $3;
      map_inj   = $4}
    in {region; value}}

injection(Kind,element):
  Kind series(element,End) {
    let first, (others, terminator, closing) = $2 in
    let region = cover $1 closing
    and value = {
      opening  = Kwd $1;
      elements = Some (first, others);
      terminator;
      closing = End closing}
    in {region; value}
  }
| Kind End {
    let region = cover $1 $2
    and value = {
      opening    = Kwd $1;
      elements   = None;
      terminator = None;
      closing    = End $2}
    in {region; value}
  }
| Kind LBRACKET series(element,RBRACKET) {
    let first, (others, terminator, closing) = $3 in
    let region = cover $1 closing
    and value = {
      opening  = KwdBracket ($1,$2);
      elements = Some (first, others);
      terminator;
      closing = RBracket closing}
    in {region; value}
  }
| Kind LBRACKET RBRACKET {
    let region = cover $1 $3
    and value = {
      opening    = KwdBracket ($1,$2);
      elements   = None;
      terminator = None;
      closing    = RBracket $3}
    in {region; value}}

map_injection:
  Map series(binding,End) {
    let first, (others, terminator, closing) = $2 in
    let region = cover $1 closing
    and value = {
      opening  = Kwd $1;
      elements = Some (first, others);
      terminator;
      closing = End closing}
    in {region; value}
  }
| Map End {
    let region = cover $1 $2
    and value = {
      opening    = Kwd $1;
      elements   = None;
      terminator = None;
      closing    = End $2}
    in {region; value}
  }
| Map LBRACKET series(binding,RBRACKET) {
    let first, (others, terminator, closing) = $3 in
    let region = cover $1 closing
    and value = {
      opening  = KwdBracket ($1,$2);
      elements = Some (first, others);
      terminator;
      closing = RBracket closing}
    in {region; value}
  }
| Map LBRACKET RBRACKET {
    let region = cover $1 $3
    and value = {
      opening    = KwdBracket ($1,$2);
      elements   = None;
      terminator = None;
      closing    = RBracket $3}
    in {region; value}}

binding:
  expr ARROW expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {
      source = $1;
      arrow  = $2;
      image  = $3}
    in {region; value}}

record_patch:
  Patch path With record_expr {
    let region = cover $1 $4.region in
    let value  = {
      kwd_patch  = $1;
      path       = $2;
      kwd_with   = $3;
      record_inj = $4}
    in {region; value}}

fail_instr:
  Fail expr {
    let region = cover $1 (expr_to_region $2)
    and value  = {kwd_fail = $1; fail_expr = $2}
    in {region; value}}

proc_call:
  fun_call { $1 }

conditional:
  If expr Then if_clause option(SEMI) Else if_clause {
    let region = cover $1 (if_clause_to_region $7) in
    let value = {
      kwd_if     = $1;
      test       = $2;
      kwd_then   = $3;
      ifso       = $4;
      terminator = $5;
      kwd_else   = $6;
      ifnot      = $7}
    in {region; value} }

if_clause:
  instruction {
    ClauseInstr $1
  }
| LBRACE series(statement,RBRACE) {
   let first, (others, terminator, closing) = $2 in
   let region = cover $1 closing in
   let value = {
     lbrace = $1;
     inside = (first, others), terminator;
     rbrace = closing} in
   ClauseBlock {value; region} }

case_instr:
  case(instruction) { $1 instr_to_region }

case(rhs):
  Case expr Of option(VBAR) cases(rhs) End {
    fun rhs_to_region ->
      let region = cover $1 $6 in
      let value  = {
        kwd_case  = $1;
        expr      = $2;
        opening   = Kwd $3;
        lead_vbar = $4;
        cases     = $5 rhs_to_region;
        closing   = End $6}
      in {region; value}
  }
| Case expr Of LBRACKET option(VBAR) cases(rhs) RBRACKET {
    fun rhs_to_region ->
      let region = cover $1 $7 in
      let value  = {
        kwd_case  = $1;
        expr      = $2;
        opening   = KwdBracket ($3,$4);
        lead_vbar = $5;
        cases     = $6 rhs_to_region;
        closing   = RBracket $7}
      in {region; value}}

cases(rhs):
  nsepseq(case_clause(rhs),VBAR) {
    fun rhs_to_region ->
      let mk_clause pre_clause = pre_clause rhs_to_region in
      let value  = Utils.nsepseq_map mk_clause $1 in
      let region = nsepseq_to_region (fun x -> x.region) value
      in {region; value}}

case_clause(rhs):
  pattern ARROW rhs {
    fun rhs_to_region ->
      let start  = pattern_to_region $1 in
      let region = cover start (rhs_to_region $3)
      and value  = {pattern=$1; arrow=$2; rhs=$3}
      in {region; value}}

assignment:
  lhs ASS rhs {
    let stop   = rhs_to_region $3 in
    let region = cover (lhs_to_region $1) stop
    and value  = {lhs = $1; assign = $2; rhs = $3}
    in {region; value}}

rhs:
  expr   {     Expr $1 }

lhs:
  path       {    Path $1 }
| map_lookup { MapPath $1 }

loop:
  while_loop { $1 }
| for_loop   { $1 }

while_loop:
  While expr block {
    let region = cover $1 $3.region
    and value  = {
      kwd_while = $1;
      cond      = $2;
      block     = $3}
    in While {region; value}}

for_loop:
  For var_assign Down? To expr option(step_clause) block {
    let region = cover $1 $7.region in
    let value = {
      kwd_for = $1;
      assign  = $2;
      down    = $3;
      kwd_to  = $4;
      bound   = $5;
      step    = $6;
      block   = $7}
    in For (ForInt {region; value})
  }
| For var option(arrow_clause) In expr block {
    let region = cover $1 $6.region in
    let value = {
      kwd_for = $1;
      var     = $2;
      bind_to = $3;
      kwd_in  = $4;
      expr    = $5;
      block   = $6}
    in For (ForCollect {region; value})}

var_assign:
  var ASS expr {
    let region = cover $1.region (expr_to_region $3)
    and value  = {name = $1; assign = $2; expr = $3}
    in {region; value}}

step_clause:
  Step expr { $1,$2 }

arrow_clause:
  ARROW var { $1,$2 }

(* Expressions *)

interactive_expr:
  expr EOF { $1 }

expr:
  case(expr) { ECase ($1 expr_to_region) }
| annot_expr  { $1                        }

annot_expr:
  LPAR disj_expr COLON type_expr RPAR {
    let start  = expr_to_region $2
    and stop   = type_expr_to_region $4 in
    let region = cover start stop
    and value  = ($2 , $4) in
    (EAnnot {region; value})
  }
| disj_expr { $1 }

disj_expr:
  disj_expr Or conj_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3} in
    ELogic (BoolExpr (Or {region; value}))
  }
| conj_expr { $1 }

conj_expr:
  conj_expr And set_membership {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (BoolExpr (And {region; value}))
  }
| set_membership { $1 }

set_membership:
  core_expr Contains set_membership {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop in
    let value  = {
      set          = $1;
      kwd_contains = $2;
      element      = $3}
    in ESet (SetMem {region; value})
  }
| comp_expr { $1 }

comp_expr:
  comp_expr LT cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Lt {region; value}))
  }
| comp_expr LEQ cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Leq {region; value}))
  }
| comp_expr GT cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Gt {region; value}))
  }
| comp_expr GEQ cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Geq {region; value}))
  }
| comp_expr EQUAL cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Equal {region; value}))
  }
| comp_expr NEQ cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in ELogic (CompExpr (Neq {region; value}))
  }
| cat_expr { $1 }

cat_expr:
  cons_expr CAT cat_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EString (Cat {region; value})
  }
| cons_expr { $1 }

cons_expr:
  add_expr CONS cons_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EList (Cons {region; value})
  }
| add_expr { $1 }

add_expr:
  add_expr PLUS mult_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EArith (Add {region; value})
  }
| add_expr MINUS mult_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EArith (Sub {region; value})
  }
| mult_expr { $1 }

mult_expr:
  mult_expr TIMES unary_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EArith (Mult {region; value})
  }
| mult_expr SLASH unary_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EArith (Div {region; value})
  }
| mult_expr Mod unary_expr {
    let start  = expr_to_region $1
    and stop   = expr_to_region $3 in
    let region = cover start stop
    and value  = {arg1 = $1; op = $2; arg2 = $3}
    in EArith (Mod {region; value})
  }
| unary_expr { $1 }

unary_expr:
  MINUS core_expr {
    let stop   = expr_to_region $2 in
    let region = cover $1 stop
    and value  = {op = $1; arg = $2}
    in EArith (Neg {region; value})
  }
| Not core_expr {
    let stop   = expr_to_region $2 in
    let region = cover $1 stop
    and value  = {op = $1; arg = $2} in
    ELogic (BoolExpr (Not {region; value}))
  }
| core_expr { $1 }

core_expr:
  Int              { EArith (Int $1)              }
| Nat              { EArith (Nat $1)              }
| Mtz              { EArith (Mtz $1)              }
| var              { EVar $1                      }
| String           { EString (String $1)          }
| Bytes            { EBytes $1                    }
| C_False          { ELogic (BoolExpr (False $1)) }
| C_True           { ELogic (BoolExpr (True  $1)) }
| C_Unit           { EUnit $1                     }
| tuple_expr       { ETuple $1                    }
| list_expr        { EList $1                     }
| C_None           { EConstr (NoneExpr $1)        }
| fun_call         { ECall $1                     }
| map_expr         { EMap $1                      }
| set_expr         { ESet $1                      }
| record_expr      { ERecord $1                   }
| projection       { EProj $1                     }
| Constr arguments {
    let region = cover $1.region $2.region in
    EConstr (ConstrApp {region; value = $1,$2})
  }
| C_Some arguments {
    let region = cover $1 $2.region in
    EConstr (SomeApp {region; value = $1,$2})}

set_expr:
  injection(Set,expr) { SetInj $1 }

map_expr:
  map_lookup    { MapLookUp $1 }
| map_injection {    MapInj $1 }

map_lookup:
  path brackets(expr) {
    let region = cover (path_to_region $1) $2.region in
    let value  = {path=$1; index=$2}
    in {region; value}}

path:
  var        { Name $1 }
| projection { Path $1 }

projection:
  struct_name DOT nsepseq(selection,DOT) {
    let stop   = nsepseq_to_region selection_to_region $3 in
    let region = cover $1.region stop
    and value  = {
      struct_name = $1;
      selector    = $2;
      field_path  = $3}
    in {region; value}}

selection:
  field_name { FieldName $1 }
| Int        { Component $1 }

record_expr:
  Record series(field_assignment,End) {
    let first, (others, terminator, closing) = $2 in
    let region = cover $1 closing
    and value = {
      opening = Kwd $1;
      elements = Some (first, others);
      terminator;
      closing = End closing}
    in {region; value}
  }
| Record LBRACKET series(field_assignment,RBRACKET) {
   let first, (others, terminator, closing) = $3 in
   let region = cover $1 closing
   and value  = {
     opening = KwdBracket ($1,$2);
     elements = Some (first, others);
     terminator;
     closing = RBracket closing}
   in {region; value} }

field_assignment:
  field_name EQUAL expr {
    let region = cover $1.region (expr_to_region $3)
    and value = {
      field_name = $1;
      equal      = $2;
      field_expr = $3}
    in {region; value}}

fun_call:
  fun_name arguments {
    let region = cover $1.region $2.region
    in {region; value = $1,$2}}

tuple_expr:
  tuple_inj { TupleInj $1 }

tuple_inj:
  par(nsepseq(expr,COMMA)) { $1 }

arguments:
  tuple_inj { $1 }

list_expr:
  injection(List,expr) { List $1 }
| Nil                  {  Nil $1 }

(* Patterns *)

pattern:
  nsepseq(core_pattern,CONS) {
    let region = nsepseq_to_region pattern_to_region $1
    in PCons {region; value=$1}}

core_pattern:
  var        {    PVar $1 }
| WILD       {   PWild $1 }
| Int        {    PInt $1 }
| String     { PString $1 }
| C_Unit     {   PUnit $1 }
| C_False    {  PFalse $1 }
| C_True     {   PTrue $1 }
| C_None     {   PNone $1 }
| list_patt  {   PList $1 }
| tuple_patt {  PTuple $1 }
| constr_patt { PConstr $1 }
| C_Some par(core_pattern) {
    let region = cover $1 $2.region
    in PSome {region; value = $1,$2}}

list_patt:
  injection(List,core_pattern) { Sugar $1 }
| Nil                          {  PNil $1 }
| par(cons_pattern)            {   Raw $1 }

cons_pattern:
  core_pattern CONS pattern { $1,$2,$3 }

tuple_patt:
  par(nsepseq(core_pattern,COMMA)) { $1 }

constr_patt:
  Constr core_pattern {
    let second =
      let region = pattern_to_region $2 in
      {region; value=$2}
    in
    let region = cover $1.region second.region in
    let value = ($1 , second) in
    {region; value}}