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 exp:
  73   | NIL
  74     {
  75       "nil[]"
  76     }
  77   | INT
  78     {
  79       sprintf "int[%d]" $1
  80     }
  81   | MINUS exp %prec UMINUS
  82     {
  83       sprintf "negation[%s]" $2
  84     }
  85   | ID LBRACK exp RBRACK OF exp
  86     {
  87       let type_id = $1 in
  88       let exp_1 = $3 in
  89       let exp_2 = $6 in
  90       sprintf "array[type[%s], size[%s], val[%s]]" type_id exp_1 exp_2
  91     }
  92   | ID LBRACE rec_field_assignments RBRACE
  93     {
  94       let type_id = $1 in
  95       let rec_field_assignments = $3 in
  96       sprintf
  97         "record[type[%s], rec_field_assignments[%s]]"
  98         type_id rec_field_assignments
  99     }
 100   | lvalue
 101     {
 102       $1
 103     }
 104   | lvalue ASSIGN exp
 105     {
 106       sprintf "assign[%s := %s]" $1 $3
 107     }
 108   | STRING
 109     {
 110       sprintf "string[%S]" $1
 111     }
 112   | ID LPAREN RPAREN
 113     {
 114       let id = $1 in
 115       sprintf "fun_call[%s, []]" id
 116     }
 117   | ID LPAREN fun_args RPAREN
 118     {
 119       let id = $1 in
 120       let fun_args = $3 in
 121       sprintf "fun_call[%s, %s]" id fun_args
 122     }
 123   | exp op exp
 124     {
 125       sprintf "op[%s %s %s]" $1 $2 $3
 126     }
 127   | IF exp THEN exp ELSE exp
 128     {
 129       let e1 = $2 in
 130       let e2 = $4 in
 131       let e3 = $6 in
 132       sprintf "if_then_else[%s, then[%s], else[%s]]" e1 e2 e3
 133     }
 134   | IF exp THEN exp
 135     {
 136       sprintf "if_then[%s, then[%s]]" $2 $4
 137     }
 138   | WHILE exp DO exp
 139     {
 140       sprintf "while[%s, do[%s]]" $2 $4
 141     }
 142   | FOR ID ASSIGN exp TO exp DO exp
 143     {
 144       let id = $2 in
 145       let e1 = $4 in
 146       let e2 = $6 in
 147       let e3 = $8 in
 148       sprintf "for[%s := %s, to[%s], do[%s]]" id e1 e2 e3
 149     }
 150   | BREAK
 151     {
 152       "break[]"
 153     }
 154   | LPAREN exps RPAREN
 155     {
 156       sprintf "exps[%s]" $2
 157     }
 158   | LET decs IN exps END
 159     {
 160       let decs = $2 in
 161       let exps = $4 in
 162       sprintf "let[decs[%s], in[exps[%s]]]" decs exps
 163     }
 164   | LPAREN RPAREN
 165     {
 166       (* Perhaps "void"? *)
 167       "unit[]"
 168     }
 169
 170 rec_field_assignments:
 171   | ID EQ exp
 172     {
 173       let id = $1 in
 174       let exp = $3 in
 175       sprintf "%S = %s" id exp
 176     }
 177   | ID EQ exp COMMA rec_field_assignments
 178     {
 179       let id = $1 in
 180       let exp = $3 in
 181       let rec_field_assignments = $5 in
 182       sprintf "%S = %s, %s" id exp rec_field_assignments
 183     }
 184
 185 exps:
 186   | exp
 187     {
 188       sprintf "%s" $1
 189     }
 190   | exp SEMICOLON exps
 191     {
 192       sprintf "%s; %s" $1 $3
 193     }
 194
 195 decs:
 196   | dec
 197     {
 198       sprintf "%s" $1
 199     }
 200   | dec decs
 201     {
 202       sprintf "%s %s" $1 $2
 203     }
 204
 205 dec:
 206   /* Tydec */
 207   | TYPE ID EQ ID
 208     {
 209       let type_id_new = $2 in
 210       let type_id_orig = $4 in
 211       sprintf "tydec_alias[from[%s], to[%s]]" type_id_new type_id_orig
 212     }
 213   | TYPE ID EQ LBRACE RBRACE
 214     {
 215       let type_id = $2 in
 216       sprintf "tydec_empty_record[%s]" type_id
 217     }
 218   | TYPE ID EQ LBRACE tyfields RBRACE
 219     {
 220       let type_id = $2 in
 221       let tyfields = $5 in
 222       sprintf "tydec_record[%s, fields[%s]]" type_id tyfields
 223     }
 224   | TYPE ID EQ ARRAY OF ID
 225     {
 226       let type_id = $2 in
 227       let element_type_id = $6 in
 228       sprintf "tydec_array[%s, elements_of_type[%s]]" type_id element_type_id
 229     }
 230
 231   /* Vardec */
 232   | VAR ID ASSIGN exp
 233     {
 234       let id = $2 in
 235       let exp = $4 in
 236       sprintf "vardec[%s, exp[%s]]" id exp
 237     }
 238   | VAR ID COLON ID ASSIGN exp
 239     {
 240       let id = $2 in
 241       let type_id = $4 in
 242       let exp = $6 in
 243       sprintf "vardec[%s, type_id[%s], exp[%s]]" id type_id exp
 244     }
 245
 246   /* Fundec */
 247   | FUNCTION ID LPAREN RPAREN EQ exp
 248     {
 249       let id       = $2 in
 250       let exp      = $6 in
 251       sprintf "fundec[%s, arguments[], exp[%s]]" id exp
 252     }
 253   | FUNCTION ID LPAREN tyfields RPAREN EQ exp
 254     {
 255       let id       = $2 in
 256       let tyfields = $4 in
 257       let exp      = $7 in
 258       sprintf "fundec[%s, arguments[%s], exp[%s]]" id tyfields exp
 259     }
 260   | FUNCTION ID LPAREN tyfields RPAREN COLON ID EQ exp
 261     {
 262       let id       = $2 in
 263       let tyfields = $4 in
 264       let type_id  = $7 in
 265       let exp      = $9 in
 266       sprintf
 267         "fundec[%s, tyfields[%s], type_id[%s], exp[%s]]"
 268         id tyfields type_id exp
 269     }
 270
 271 tyfields:
 272   | ID COLON ID
 273     {
 274       let id_1 = $1 in
 275       let id_2 = $3 in
 276       sprintf "%s : %s" id_1 id_2
 277     }
 278   | ID COLON ID COMMA tyfields
 279     {
 280       let id_1 = $1 in
 281       let id_2 = $3 in
 282       let tyfield = sprintf "%s : %s" id_1 id_2 in
 283       let tyfields = $5 in
 284       sprintf "%s, %s" tyfield tyfields
 285     }
 286
 287 fun_args:
 288   | exp
 289     {
 290       $1
 291     }
 292   | exp COMMA fun_args
 293     {
 294       sprintf "%s, %s" $1 $3
 295     }
 296
 297 op:
 298   | PLUS   {"+"}
 299   | MINUS  {"-"}
 300   | TIMES  {"*"}
 301   | DIVIDE {"/"}
 302   | EQ     {"="}
 303   | NEQ    {"<>"}
 304   | GT     {">"}
 305   | LT     {"<"}
 306   | GE     {">="}
 307   | LE     {"<="}
 308   | AND    {"&"}
 309   | OR     {"|"}
 310
 311 lvalue:
 312   | ID
 313     {
 314       let id = $1 in
 315       sprintf "lvalue[%s]" id
 316     }
 317   | lvalue DOT ID
 318     {
 319       let record = $1 in
 320       let field = $3 in
 321       sprintf "get_record_field[%s, %s]" record field
 322     }
 323   | lvalue LBRACK exp RBRACK
 324     {
 325       let array = $1 in
 326       let subscript = $3 in
 327       sprintf "get_array_subscript[%s, %s]" array subscript
 328     }
 329
 330 %%