%{
open Ast
%}

%token LPAREN
%token RPAREN
%token <int> INTEGER
%token IF
%token DECISION
%token <string> STRING
%token CASE
%token ELSEIF
%token UNDERSCORE
%token ARM
%token EQUALS
%token AND
%token OR
%token VAR

%type <Ast.rule list> character
%start character

%%

character: LPAREN rulelist RPAREN       { List.rev $2 }
;

rulelist:
  /*empty*/                             { [] }
| rulelist rule                         { $2 :: $1 }
;

rule: LPAREN intlist stmt RPAREN        { (List.rev $2, $3) }
;

intlist:
  /*empty*/                             { [] }
| intlist INTEGER                       { $2 :: $1 }
;

stmt:
  LPAREN IF condition stmt LPAREN iftail RPAREN { Eif($3, $4, $6) }
| LPAREN DECISION newstate STRING RPAREN        { Edecision {next = $3;
                                                             utterance = $4} }
| LPAREN CASE variable LPAREN armlist RPAREN stmt RPAREN
                                                { Ecase($3, List.rev $5, $7) }
;

iftail:
  RPAREN stmt                                   { $2 }
| LPAREN ELSEIF condition stmt RPAREN iftail    { Eif($3, $4, $6) }
;

newstate:
  INTEGER                                       { NSfixed $1 }
| UNDERSCORE                                    { NSdefault }
;

armlist:
  /*empty*/                                     { [] }
| armlist LPAREN ARM LPAREN intlist RPAREN stmt RPAREN
                                                { (List.rev $5, $7) :: $1 }
;

condition:
  LPAREN EQUALS variable INTEGER RPAREN         { Cequals($3, $4) }
| LPAREN AND conditionlist RPAREN               { Cand(List.rev $3) }
| LPAREN OR conditionlist RPAREN                { Cor(List.rev $3) }
;

conditionlist:
  /*empty */                                    { [] }
| conditionlist condition                       { $2 :: $1 }
;

variable:
  LPAREN VAR STRING RPAREN                      { $3 }
;

%%