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