parse.y

   1 %{
   2 #include <stdio.h>
   3
   4 #include "ast.h"
   5 #include "parse.h"
   6
   7 int yylex(void);
   8 extern YYLTYPE yylloc;
   9
  10 void yyerror(struct ast **result, const char *str)
  11 {
  12         (void)result;
  13         fprintf(stderr, "%d-%d: %s\n", yylloc.first_line, yylloc.last_column, str);
  14 }
  15
  16 int yywrap()
  17 {
  18         return 1;
  19 }
  20
  21 %}
  22
  23 %define parse.lac full
  24 %define parse.error verbose
  25
  26 %union {
  27         struct expr *expr;
  28         struct stmt *stmt;
  29         struct list *list;
  30         struct vardecl *vardecl;
  31         struct decl *decl;
  32         struct type *type;
  33         char *ident;
  34 }
  35
  36 %locations
  37 %token <ident> IDENT
  38 %token <expr> BOOL CHAR INTEGER STRING
  39 %token ARROW ASSIGN BCLOSE BINAND BINOR BOPEN CCLOSE COMMA CONS COPEN DIVIDE
  40 %token DOT ELSE ERROR IF INVERSE MINUS MODULO NIL PLUS POWER RETURN SEMICOLON
  41 %token SCLOSE SOPEN TIMES TBOOL TCHAR TINT TVOID VAR WHILE
  42
  43 %parse-param { struct ast **result }
  44
  45 %right BINOR
  46 %right BINAND
  47 %nonassoc EQ NEQ LEQ LE GEQ GE
  48 %right CONS
  49 %left PLUS MINUS
  50 %left TIMES DIVIDE MODULO
  51 %right POWER
  52
  53 %type <ast> start
  54 %type <decl> fundecl
  55 %type <expr> expr
  56 %type <list> args body decls fargs field fnargs nargs funtype bbody
  57 %type <stmt> stmt
  58 %type <type> type ftype
  59 %type <vardecl> vardecl
  60
  61 %%
  62
  63 start : decls { *result = ast($1); } ;
  64 decls
  65         : /* empty */ { $$ = NULL; }
  66         | decls vardecl { $$ = list_cons(decl_var($2), $1); }
  67         | decls fundecl { $$ = list_cons($2, $1); }
  68         ;
  69 vardecl
  70         : VAR IDENT ASSIGN expr SEMICOLON { $$ = vardecl(NULL, $2, $4); }
  71         | type IDENT ASSIGN expr SEMICOLON { $$ = vardecl($1, $2, $4); }
  72         ;
  73 fundecl
  74         : IDENT BOPEN args BCLOSE COPEN body CCLOSE
  75                 { $$ = decl_fun($1, $3, NULL, NULL, $6); }
  76         | IDENT BOPEN args BCLOSE CONS CONS funtype ARROW ftype COPEN body CCLOSE
  77                 { $$ = decl_fun($1, $3, $7, $9, $11); }
  78         ;
  79 funtype
  80         : /* empty */ { $$ = NULL; }
  81         | funtype ftype { $$ = list_cons($2, $1); }
  82         ;
  83 /* don't allow vardecls to be fully polymorph, this complicates parsing a lot */
  84 type
  85         : BOPEN ftype COMMA ftype BCLOSE { $$ = type_tuple($2, $4); }
  86         | SOPEN ftype SCLOSE { $$ = type_list($2); }
  87         | TBOOL { $$ = type_basic(btbool); }
  88         | TCHAR { $$ = type_basic(btchar); }
  89         | TINT { $$ = type_basic(btint); }
  90         | TVOID { $$ = type_basic(btvoid); }
  91         ;
  92 ftype
  93         : type
  94     | IDENT { $$ = type_var($1); }
  95         ;
  96 args
  97         : /* empty */ { $$ = NULL; }
  98         | nargs
  99         ;
 100 nargs
 101         : nargs COMMA IDENT { $$ = list_cons($3, $1); }
 102         | IDENT { $$ = list_cons($1, NULL); }
 103         ;
 104 fargs
 105         : /* empty */ { $$ = NULL; }
 106         | fnargs
 107         ;
 108 fnargs
 109         : fnargs COMMA expr { $$ = list_cons($3, $1); }
 110         | expr { $$ = list_cons($1, NULL); }
 111         ;
 112 body
 113         : /* empty */ { $$ = NULL; }
 114         | body stmt { $$ = list_cons($2, $1); }
 115         ;
 116 field
 117         : /* empty */ { $$ = NULL; }
 118         | field DOT IDENT { $$ = list_cons($3, $1); }
 119         ;
 120 bbody
 121         : COPEN body CCLOSE { $$ = $2; }
 122         | stmt { $$ = list_cons($1, NULL); }
 123         ;
 124 stmt
 125         : IF BOPEN expr BCLOSE bbody { $$ = stmt_if($3, $5, NULL); }
 126         | IF BOPEN expr BCLOSE bbody ELSE bbody { $$ = stmt_if($3, $5, $7); }
 127         | WHILE BOPEN expr BCLOSE bbody { $$ = stmt_while($3, $5); }
 128         | IDENT field ASSIGN expr SEMICOLON { $$ = stmt_assign($1, $2, $4); }
 129         | RETURN expr SEMICOLON { $$ = stmt_return($2); }
 130         | RETURN SEMICOLON { $$ = stmt_return(NULL); }
 131         | vardecl { $$ = stmt_vardecl($1); }
 132         | expr SEMICOLON { $$ = stmt_expr($1); }
 133         ;
 134 expr
 135         : expr BINOR expr { $$ = expr_binop($1, binor, $3); }
 136         | expr BINAND expr { $$ = expr_binop($1, binand, $3); }
 137         | expr EQ expr { $$ = expr_binop($1, eq, $3); }
 138         | expr NEQ expr { $$ = expr_binop($1, neq, $3); }
 139         | expr LEQ expr { $$ = expr_binop($1, leq, $3); }
 140         | expr LE expr { $$ = expr_binop($1, le, $3); }
 141         | expr GEQ expr { $$ = expr_binop($1, geq, $3); }
 142         | expr GE expr { $$ = expr_binop($1, ge, $3); }
 143         | expr CONS expr { $$ = expr_binop($1, cons, $3); }
 144         | expr PLUS expr { $$ = expr_binop($1, plus, $3); }
 145         | expr MINUS expr { $$ = expr_binop($1, minus, $3); }
 146         | expr TIMES expr { $$ = expr_binop($1, times, $3); }
 147         | expr DIVIDE expr { $$ = expr_binop($1, divide, $3); }
 148         | expr MODULO expr { $$ = expr_binop($1, modulo, $3); }
 149         | expr POWER expr { $$ = expr_binop($1, power, $3); }
 150         | MINUS expr %prec TIMES { $$ = expr_unop(negate, $2); }
 151         | INVERSE expr %prec TIMES { $$ = expr_unop(inverse, $2); }
 152         | IDENT BOPEN fargs BCLOSE field { $$ = expr_funcall($1, $3, $5); }
 153         | BOPEN expr COMMA expr BCLOSE { $$ = expr_tuple($2, $4); }
 154         | BOPEN expr BCLOSE { $$ = $2; }
 155         | INTEGER
 156         | BOOL
 157         | CHAR
 158         | STRING
 159         | IDENT field { $$ = expr_ident($1, $2); }
 160         | NIL { $$ = expr_nil(); }
 161         ;