1 typedef void (*Inst)(void); 2 #define STOP (Inst) 0 3 4 typedef struct Symbol Symbol; 5 typedef union Datum Datum; 6 typedef struct Formal Formal; 7 typedef struct Saveval Saveval; 8 typedef struct Fndefn Fndefn; 9 typedef union Symval Symval; 10 11 union Symval { /* value of a symbol */ 12 double val; /* VAR */ 13 double (*ptr)(double); /* BLTIN */ 14 Fndefn *defn; /* FUNCTION, PROCEDURE */ 15 char *str; /* STRING */ 16 }; 17 18 struct Symbol { /* symbol table entry */ 19 char *name; 20 long type; 21 Symval u; 22 struct Symbol *next; /* to link to another */ 23 }; 24 Symbol *install(char*, int, double), *lookup(char*); 25 26 union Datum { /* interpreter stack type */ 27 double val; 28 Symbol *sym; 29 }; 30 31 struct Saveval { /* saved value of variable */ 32 Symval val; 33 long type; 34 Saveval *next; 35 }; 36 37 struct Formal { /* formal parameter */ 38 Symbol *sym; 39 Saveval *save; 40 Formal *next; 41 }; 42 43 struct Fndefn { /* formal parameter */ 44 Inst *code; 45 Formal *formals; 46 int nargs; 47 }; 48 49 extern Formal *formallist(Symbol*, Formal*); 50 extern double Fgetd(int); 51 extern int moreinput(void); 52 extern void restore(Symbol*); 53 extern void restoreall(void); 54 extern void execerror(char*, char*); 55 extern void define(Symbol*, Formal*), verify(Symbol*); 56 extern Datum pop(void); 57 extern void initcode(void), push(Datum), xpop(void), constpush(void); 58 extern void varpush(void); 59 extern void eval(void), add(void), sub(void), mul(void), div(void), mod(void); 60 extern void negate(void), power(void); 61 extern void addeq(void), subeq(void), muleq(void), diveq(void), modeq(void); 62 63 extern Inst *progp, *progbase, prog[], *code(Inst); 64 extern void assign(void), bltin(void), varread(void); 65 extern void prexpr(void), prstr(void); 66 extern void gt(void), lt(void), eq(void), ge(void), le(void), ne(void); 67 extern void and(void), or(void), not(void); 68 extern void ifcode(void), whilecode(void), forcode(void); 69 extern void call(void), arg(void), argassign(void); 70 extern void funcret(void), procret(void); 71 extern void preinc(void), predec(void), postinc(void), postdec(void); 72 extern void execute(Inst*); 73 extern void printtop(void); 74 75 extern double Log(double), Log10(double), Gamma(double), Sqrt(double), Exp(double); 76 extern double Asin(double), Acos(double), Sinh(double), Cosh(double), integer(double); 77 extern double Pow(double, double); 78 79 extern void init(void); 80 extern int yyparse(void); 81 extern void execerror(char*, char*); 82 extern void *emalloc(unsigned); 83