tiger/src/lib/tiger/tiger_parser.mly

   1 %{
   2   open Printf
   3 %}
   4
   5 /* Declarations */
   6 %token AND
   7 %token ARRAY
   8 %token ASSIGN
   9 %token BREAK
  10 %token COLON
  11 %token COMMA
  12 %token DIVIDE
  13 %token DO
  14 %token DOT
  15 %token ELSE
  16 %token END
  17 %token EOF
  18 %token EQ
  19 %token FOR
  20 %token FUNCTION
  21 %token GE
  22 %token GT
  23 %token <string> ID
  24 %token IF
  25 %token IN
  26 %token <int> INT
  27 %token LBRACE
  28 %token LBRACK
  29 %token LE
  30 %token LET
  31 %token LPAREN
  32 %token LT
  33 %token MINUS
  34 %token NEQ
  35 %token NIL
  36 %token OF
  37 %token OR
  38 %token PLUS
  39 %token RBRACE
  40 %token RBRACK
  41 %token RPAREN
  42 %token SEMICOLON
  43 %token <string> STRING
  44 %token THEN
  45 %token TIMES
  46 %token TO
  47 %token TYPE
  48 %token VAR
  49 %token WHILE
  50
  51 /* from lowest precedence */
  52 %left THEN
  53 %left ELSE
  54 %nonassoc ASSIGN
  55 %left OF DO
  56 %left OR
  57 %left AND
  58 %nonassoc EQ NEQ GT LT GE LE
  59 %left PLUS MINUS
  60 %left TIMES DIVIDE
  61 %nonassoc UMINUS
  62 /* to highest precedence */
  63
  64 %type <string> program
  65
  66 %start program
  67
  68 %%
  69
  70 program:
  71   | exp EOF
  72     {
  73       sprintf "program[%s]" $1
  74     }
  75   ;
  76
  77 exp:
  78   | NIL
  79     {
  80       "nil[]"
  81     }
  82   | INT
  83     {
  84       sprintf "int[%d]" $1
  85     }
  86   | MINUS exp %prec UMINUS
  87     {
  88       sprintf "negation[%s]" $2
  89     }
  90   | ID LBRACK exp RBRACK OF exp
  91     {
  92       let type_id = $1 in
  93       let number_of_elements = $3 in
  94       let initial_value = $6 in
  95       sprintf
  96         "array[type[%s], size[%s], val[%s]]"
  97         type_id number_of_elements initial_value
  98     }
  99   | ID LBRACE rec_field_assignments RBRACE
 100     {
 101       let type_id = $1 in
 102       let rec_field_assignments = $3 in
 103       sprintf
 104         "record[type[%s], rec_field_assignments[%s]]"
 105         type_id rec_field_assignments
 106     }
 107   | lvalue
 108     {
 109       $1
 110     }
 111   | lvalue ASSIGN exp
 112     {
 113       sprintf "assign[%s := %s]" $1 $3
 114     }
 115   | STRING
 116     {
 117       sprintf "string[%S]" $1
 118     }
 119   | ID LPAREN RPAREN
 120     {
 121       let id = $1 in
 122       sprintf "fun_call[%s, []]" id
 123     }
 124   | ID LPAREN fun_args RPAREN
 125     {
 126       let id = $1 in
 127       let fun_args = $3 in
 128       sprintf "fun_call[%s, %s]" id fun_args
 129     }
 130   | exp op exp
 131     {
 132       sprintf "op[%s %s %s]" $1 $2 $3
 133     }
 134   | IF exp THEN exp ELSE exp
 135     {
 136       let e1 = $2 in
 137       let e2 = $4 in
 138       let e3 = $6 in
 139       sprintf "if_then_else[%s, then[%s], else[%s]]" e1 e2 e3
 140     }
 141   | IF exp THEN exp
 142     {
 143       sprintf "if_then[%s, then[%s]]" $2 $4
 144     }
 145   | WHILE exp DO exp
 146     {
 147       sprintf "while[%s, do[%s]]" $2 $4
 148     }
 149   | FOR ID ASSIGN exp TO exp DO exp
 150     {
 151       let id = $2 in
 152       let e1 = $4 in
 153       let e2 = $6 in
 154       let e3 = $8 in
 155       sprintf "for[%s := %s, to[%s], do[%s]]" id e1 e2 e3
 156     }
 157   | BREAK
 158     {
 159       "break[]"
 160     }
 161   | LPAREN exps RPAREN
 162     {
 163       sprintf "exps[%s]" $2
 164     }
 165   | LET decs IN exps END
 166     {
 167       let decs = $2 in
 168       let exps = $4 in
 169       sprintf "let[decs[%s], in[exps[%s]]]" decs exps
 170     }
 171   | LPAREN RPAREN
 172     {
 173       (* Perhaps "void"? *)
 174       "unit[]"
 175     }
 176   ;
 177
 178 rec_field_assignments:
 179   | ID EQ exp
 180     {
 181       let id = $1 in
 182       let exp = $3 in
 183       sprintf "%S = %s" id exp
 184     }
 185   | ID EQ exp COMMA rec_field_assignments
 186     {
 187       let id = $1 in
 188       let exp = $3 in
 189       let rec_field_assignments = $5 in
 190       sprintf "%S = %s, %s" id exp rec_field_assignments
 191     }
 192   ;
 193
 194 exps:
 195   | exp
 196     {
 197       let exp = $1 in
 198       sprintf "%s" exp
 199     }
 200   | exp SEMICOLON exps
 201     {
 202       let exp = $1 in
 203       let exps = $3 in
 204       sprintf "%s; %s" exp exps
 205     }
 206   ;
 207
 208 decs:
 209   | dec
 210     {
 211       sprintf "%s" $1
 212     }
 213   | dec decs
 214     {
 215       sprintf "%s %s" $1 $2
 216     }
 217   ;
 218
 219 dec:
 220   /* Tydec */
 221   | TYPE ID EQ ID
 222     {
 223       let type_id_new = $2 in
 224       let type_id_orig = $4 in
 225       sprintf "tydec_alias[from[%s], to[%s]]" type_id_new type_id_orig
 226     }
 227   | TYPE ID EQ LBRACE RBRACE
 228     {
 229       let type_id = $2 in
 230       sprintf "tydec_empty_record[%s]" type_id
 231     }
 232   | TYPE ID EQ LBRACE tyfields RBRACE
 233     {
 234       let type_id = $2 in
 235       let tyfields = $5 in
 236       sprintf "tydec_record[%s, fields[%s]]" type_id tyfields
 237     }
 238   | TYPE ID EQ ARRAY OF ID
 239     {
 240       let type_id = $2 in
 241       let element_type_id = $6 in
 242       sprintf "tydec_array[%s, elements_of_type[%s]]" type_id element_type_id
 243     }
 244
 245   /* Vardec */
 246   | VAR ID ASSIGN exp
 247     {
 248       let id = $2 in
 249       let exp = $4 in
 250       sprintf "vardec[%s, exp[%s]]" id exp
 251     }
 252   | VAR ID COLON ID ASSIGN exp
 253     {
 254       let id = $2 in
 255       let type_id = $4 in
 256       let exp = $6 in
 257       sprintf "vardec[%s, type_id[%s], exp[%s]]" id type_id exp
 258     }
 259
 260   /* Fundec */
 261   | FUNCTION ID LPAREN RPAREN EQ exp
 262     {
 263       let id       = $2 in
 264       let exp      = $6 in
 265       sprintf "fundec[%s, arguments[], exp[%s]]" id exp
 266     }
 267   | FUNCTION ID LPAREN tyfields RPAREN EQ exp
 268     {
 269       let id       = $2 in
 270       let tyfields = $4 in
 271       let exp      = $7 in
 272       sprintf "fundec[%s, arguments[%s], exp[%s]]" id tyfields exp
 273     }
 274   | FUNCTION ID LPAREN tyfields RPAREN COLON ID EQ exp
 275     {
 276       let id       = $2 in
 277       let tyfields = $4 in
 278       let type_id  = $7 in
 279       let exp      = $9 in
 280       sprintf
 281         "fundec[%s, tyfields[%s], type_id[%s], exp[%s]]"
 282         id tyfields type_id exp
 283     }
 284   ;
 285
 286 tyfields:
 287   | ID COLON ID
 288     {
 289       let id_1 = $1 in
 290       let id_2 = $3 in
 291       sprintf "%s : %s" id_1 id_2
 292     }
 293   | ID COLON ID COMMA tyfields
 294     {
 295       let id_1 = $1 in
 296       let id_2 = $3 in
 297       let tyfield = sprintf "%s : %s" id_1 id_2 in
 298       let tyfields = $5 in
 299       sprintf "%s, %s" tyfield tyfields
 300     }
 301   ;
 302
 303 fun_args:
 304   | exp
 305     {
 306       $1
 307     }
 308   | exp COMMA fun_args
 309     {
 310       sprintf "%s, %s" $1 $3
 311     }
 312   ;
 313
 314 op:
 315   | PLUS   {"+"}
 316   | MINUS  {"-"}
 317   | TIMES  {"*"}
 318   | DIVIDE {"/"}
 319   | EQ     {"="}
 320   | NEQ    {"<>"}
 321   | GT     {">"}
 322   | LT     {"<"}
 323   | GE     {">="}
 324   | LE     {"<="}
 325   | AND    {"&"}
 326   | OR     {"|"}
 327   ;
 328
 329 lvalue:
 330   | ID lvalue_part
 331     {
 332       let id = $1 in
 333       let part = $2 in
 334       sprintf "lvalue[%s, part[%s]]" id part
 335     }
 336   ;
 337
 338 lvalue_part:
 339   | {"epsilon[]"}
 340   | lvalue_subscript {$1}
 341   | lvalue_field_access {$1}
 342   ;
 343
 344 lvalue_subscript:
 345   | LBRACK exp RBRACK
 346     {
 347       let exp = $2 in
 348       sprintf "subscript[%s]" exp
 349     }
 350   ;
 351
 352 lvalue_field_access:
 353   | DOT ID
 354     {
 355       let field = $2 in
 356       sprintf "field_access[%s]" field
 357     }
 358   ;
 359
 360 %%