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