parse.y

   1 %{
   2 #include <stdio.h>
   3
   4 #include "ast.h"
   5 #include "y.tab.h"
   6
   7 int yylex(void);
   8 extern YYLTYPE yylloc;
   9
  10 void yyerror(struct ast **result, const char *str)
  11 {
  12         fprintf(stderr, "%d-%d: %s\n", yylloc.first_line, yylloc.last_column, str);
  13         (void)result;
  14 }
  15
  16 int yywrap()
  17 {
  18         return 1;
  19 }
  20
  21 %}
  22
  23 %union {
  24         struct expr *expr;
  25         struct stmt *stmt;
  26         struct list *list;
  27         struct vardecl *vardecl;
  28         struct decl *decl;
  29         struct type *type;
  30         char *ident;
  31 }
  32
  33 %locations
  34 %token <ident> IDENT
  35 %token <expr> BOOL CHAR INTEGER STRING
  36 %token ARROW ASSIGN BCLOSE BINAND BINOR BOPEN CCLOSE COMMA CONS COPEN DIVIDE
  37 %token DOT ELSE ERROR IF INVERSE MINUS MODULO NIL PLUS POWER RETURN SEMICOLON
  38 %token SCLOSE SOPEN TIMES TBOOL TCHAR TINT TVOID VAR WHILE
  39
  40 %parse-param { struct ast **result }
  41
  42 %right BINOR
  43 %right BINAND
  44 %nonassoc EQ NEQ LEQ LE GEQ GE
  45 %right CONS
  46 %left PLUS MINUS
  47 %left TIMES DIVIDE MODULO
  48 %right POWER
  49
  50 %type <ast> start
  51 %type <decl> fundecl
  52 %type <expr> expr
  53 %type <list> args body decls fargs field fnargs nargs funtype vardecls bbody
  54 %type <stmt> stmt
  55 %type <type> type ftype
  56 %type <vardecl> vardecl
  57
  58 %%
  59
  60 start : decls { *result = ast($1); } ;
  61 decls
  62         : /* empty */ { $$ = NULL; }
  63         | decls vardecl { $$ = list_cons(decl_var($2), $1); }
  64         | decls fundecl { $$ = list_cons($2, $1); }
  65         ;
  66 vardecl
  67         : VAR IDENT ASSIGN expr SEMICOLON { $$ = vardecl(NULL, $2, $4); }
  68         | type IDENT ASSIGN expr SEMICOLON { $$ = vardecl($1, $2, $4); }
  69         ;
  70 fundecl
  71         : IDENT BOPEN args BCLOSE CONS CONS funtype ARROW ftype COPEN vardecls body CCLOSE
  72                 { $$ = decl_fun($1, $3, $7, $9, $11, $12); }
  73         | IDENT BOPEN args BCLOSE COPEN vardecls body CCLOSE
  74                 { $$ = decl_fun($1, $3, NULL, NULL, $6, $7); }
  75         ;
  76 vardecls
  77         : /* empty */ { $$ = NULL; }
  78         | vardecls vardecl { $$ = list_cons($2, $1); }
  79         ;
  80 funtype
  81         : /* empty */ { $$ = NULL; }
  82         | funtype ftype { $$ = list_cons($2, $1); }
  83         ;
  84 /* don't allow vardecls to be fully polymorph, this complicates parsing a lot */
  85 type
  86         : BOPEN ftype COMMA ftype BCLOSE { $$ = type_tuple($2, $4); }
  87         | SOPEN ftype SCLOSE { $$ = type_list($2); }
  88         | TBOOL { $$ = type_basic(btbool); }
  89         | TCHAR { $$ = type_basic(btchar); }
  90         | TINT { $$ = type_basic(btint); }
  91         | TVOID { $$ = type_basic(btvoid); }
  92         ;
  93 ftype
  94         : BOPEN ftype COMMA ftype BCLOSE { $$ = type_tuple($2, $4); }
  95         | SOPEN ftype SCLOSE { $$ = type_list($2); }
  96         | TBOOL { $$ = type_basic(btbool); }
  97         | TCHAR { $$ = type_basic(btchar); }
  98         | TINT { $$ = type_basic(btint); }
  99         | TVOID { $$ = type_basic(btvoid); }
 100     | IDENT { $$ = type_var($1); }
 101         ;
 102 args
 103         : /* empty */ { $$ = NULL; }
 104         | nargs
 105         ;
 106 nargs
 107         : nargs COMMA IDENT { $$ = list_cons($3, $1); }
 108         | IDENT { $$ = list_cons($1, NULL); }
 109         ;
 110 fargs
 111         : /* empty */ { $$ = NULL; }
 112         | fnargs
 113         ;
 114 fnargs
 115         : fnargs COMMA expr { $$ = list_cons($3, $1); }
 116         | expr { $$ = list_cons($1, NULL); }
 117         ;
 118 body
 119         : /* empty */ { $$ = NULL; }
 120         | body stmt { $$ = list_cons($2, $1); }
 121         ;
 122 field
 123         : /* empty */ { $$ = NULL; }
 124         | field DOT IDENT { $$ = list_cons($3, $1); }
 125         ;
 126 bbody
 127         : COPEN body CCLOSE { $$ = $2; }
 128         | stmt { $$ = list_cons($1, NULL); }
 129         ;
 130 stmt
 131         : IF BOPEN expr BCLOSE bbody { $$ = stmt_if($3, $5, NULL); }
 132         | IF BOPEN expr BCLOSE bbody ELSE bbody { $$ = stmt_if($3, $5, $7); }
 133         | WHILE BOPEN expr BCLOSE bbody { $$ = stmt_while($3, $5); }
 134         | IDENT field ASSIGN expr SEMICOLON { $$ = stmt_assign($1, $2, $4); }
 135         | RETURN expr SEMICOLON { $$ = stmt_return($2); }
 136         | RETURN SEMICOLON { $$ = stmt_return(NULL); }
 137         | vardecl { $$ = stmt_vardecl($1); }
 138         | expr SEMICOLON { $$ = stmt_expr($1); }
 139         ;
 140 expr
 141         : expr BINOR expr { $$ = expr_binop($1, binor, $3); }
 142         | expr BINAND expr { $$ = expr_binop($1, binand, $3); }
 143         | expr EQ expr { $$ = expr_binop($1, eq, $3); }
 144         | expr NEQ expr { $$ = expr_binop($1, neq, $3); }
 145         | expr LEQ expr { $$ = expr_binop($1, leq, $3); }
 146         | expr LE expr { $$ = expr_binop($1, le, $3); }
 147         | expr GEQ expr { $$ = expr_binop($1, geq, $3); }
 148         | expr GE expr { $$ = expr_binop($1, ge, $3); }
 149         | expr CONS expr { $$ = expr_binop($1, cons, $3); }
 150         | expr PLUS expr { $$ = expr_binop($1, plus, $3); }
 151         | expr MINUS expr { $$ = expr_binop($1, minus, $3); }
 152         | expr TIMES expr { $$ = expr_binop($1, times, $3); }
 153         | expr DIVIDE expr { $$ = expr_binop($1, divide, $3); }
 154         | expr MODULO expr { $$ = expr_binop($1, modulo, $3); }
 155         | expr POWER expr { $$ = expr_binop($1, power, $3); }
 156         | MINUS expr %prec TIMES { $$ = expr_unop(negate, $2); }
 157         | INVERSE expr %prec TIMES { $$ = expr_unop(inverse, $2); }
 158         | IDENT BOPEN fargs BCLOSE field { $$ = expr_funcall($1, $3, $5); }
 159         | BOPEN expr COMMA expr BCLOSE { $$ = expr_tuple($2, $4); }
 160         | BOPEN expr BCLOSE { $$ = $2; }
 161         | INTEGER
 162         | BOOL
 163         | CHAR
 164         | STRING
 165         | IDENT field { $$ = expr_ident($1, $2); }
 166         | NIL { $$ = expr_nil(); }
 167         ;