buf_header.h

/*
* Declarations for a calculator fb3-1
*/
/* interface to the lexer */
extern int yylineno; /* from lexer */
void yyerror(char *s, ...);

/* symbol table */
struct symbol { /* a variable name */
    char *name;
    double value;
    struct ast *func; /* stmt for the function */
    struct symlist *syms; /* list of dummy args */
};
/* simple symtab of fixed size */

struct symbol *lookup(char*);
/* list of symbols, for an argument list */
struct symlist {
    struct symbol *sym;
    struct symlist *next;
};


struct symlist *newsymlist(struct symbol *sym, struct symlist *next);
void symlistfree(struct symlist *sl);

/* node types
* + - * / |
* 0-7 comparison ops, bit coded 04 equal, 02 less, 01 greater
* M unary minus
* L expression or statement list
* I IF statement
* W WHILE statement
* N symbol ref
* = assignment
* S list of symbols
* F built in function call
* C user function call
*/
enum bifs { /* built-in functions */
    B_sqrt = 1,
    B_exp,
    B_log,
    B_print,
    B_sin,
    B_cos,
    B_tan,
    B_asin,
    B_acos,
    B_atan,
    B_rand
};

enum bifs2 {
    B_pow = 1,
    B_atan2,
};

struct fncall2 {
    int nodetype;
    struct ast* l;
    struct ast *r;
    enum bifs2 functype;
};
/* nodes in the abstract syntax tree */
/* all have common initial nodetype */
struct ast {
    int nodetype;
    struct ast *l;
    struct ast *r;
};

struct fncall { /* built-in function */
    int nodetype; /* type F */
    struct ast *l; //exp or explist
    //struct ast *r;
    enum bifs functype;
};

struct ufncall { /* user function */
    int nodetype; /* type C */
    struct ast *l; /* list of arguments */
    struct symbol *s;
};

struct flow {
    int nodetype; /* type I or W */
    struct ast *cond; /* condition */
    struct ast *tl; /* then branch or do list */
    struct ast *el; /* optional else branch */
};

struct numval {
    int nodetype; /* type K */
    double number;
};

struct ast_string {
    int nodetype;
    char *value;
};

struct symref { /*references to sumbols*/
    int nodetype; /* type N */
    struct symbol *s;
};

struct symasgn {
    int nodetype; /* type = */
    struct symbol *s;
    struct ast *v; /* value */
};
/* build an AST */
struct ast *newast(int nodetype, struct ast *l, struct ast *r);
struct ast *newcmp(int cmptype, struct ast *l, struct ast *r);
struct ast *newfunc(int functype, struct ast *l);
struct ast *newfunc2(int functype, struct ast *l, struct ast *r);
struct ast *newcall(struct symbol *s, struct ast *l);
struct ast *newref(struct symbol *s);
struct ast *newasgn(struct symbol *s, struct ast *v);
struct ast *newnum(double d);
struct ast *newflow(int nodetype, struct ast *cond, struct ast *tl, struct ast *tr);
struct ast *newstring(const char *value);
/* define a function */
void dodef(struct symbol *name, struct symlist *syms, struct ast *stmts);
/* evaluate an AST */
double eval(struct ast *);
/* delete and free an AST */
void treefree(struct ast *);
/* interface to the lexer */
extern int yylineno; /* from lexer */
void yyerror(char *s, ...);