%{
    #include <stdio.h>
%}

/* declared tokens */
%token INT
%token FLOAT
%token ID
%token SEMI
%token COMMA
%token ASSIGNOP
%token RELOP
%token PLUS
%token MINUS
%token STAR
%token DIV
%token AND
%token OR
%token DOT
%token NOT
%token TYPE
/* TYPE -> int | float见下面 */
%token LP
%token RP
%token LB
%token RB
%token LC
%token RC
%token STRUCT
%token RETURN
%token IF
%token ELSE
%token WHILE

%%
/*High-level Definitions */

Program : ExtDefList
    ;
ExtDefList : ExtDef ExtDefList
    | 
    ;
ExtDef : Specifier ExtDecList SEMI
    | Specifier SEMI
    | Specifier FunDec CompSt
    ;
ExtDecList : VarDec
    | VarDec COMMA ExtDecList
    ;

/*Specifier */

Specifier : TYPE
    | StructSpecifier
    ;
StructSpecifier : STRUCT OptTag LC DefList RC
    | STRUCT Tag
    ;
OptTag : ID
    | 
    ;
Tag : ID

/*Declarators */

VarDec : ID
    | VarDec LB INT RB
    ;
FunDec : ID LP VarList RP
    | ID LP RP
    ;
VarList : ParamDec COMMA VarList
    | ParamDec
    ;
ParamDec : Specifier VarDec
    ;

/*Statements */

CompSt : LC DefList StmtList RC
    ;
StmtList : Stmt StmtList
    | 
    ;
Stmt : Exp SEMI
    | CompSt
    | RETURN Exp SEMI
    | IF LP Exp RP Stmt
    | IF LP Exp RP Stmt ELSE Stmt
    | WHILE LP Exp RP Stmt
    ;

/*Local Definitions */

DefList : Def DefList
    | 
    ;
Def : Specifier DecList SEMI
    ;
DecList : Dec
    | Dec COMMA DecList
    ;
Dec : VarDec
    | VarDec ASSIGNOP Exp

/*Expressions */

Exp : Exp ASSIGNOP Exp
    | Exp AND Exp
    | Exp OR Exp
    | Exp RELOP Exp
    | Exp PLUS Exp
    | Exp MINUS Exp
    | Exp STAR Exp
    | Exp DIV Exp
    | LP Exp RP
    | MINUS Exp
    | NOT Exp
    | ID LP Args RP
    | ID LP RP
    | Exp LB Exp RB
    | Exp DOT ID
    | ID
    | INT
    | FLOAT
    ;
Args : Exp COMMA Args
    | Exp
    ;


%%