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