watcompiler.h

#include <stdint.h>

#define SEED 8699

/* symbol table */
struct symbol { /* a variable name */
  char *name;
  uint8_t offset;
};

/* node types
 * + - * / %
 * M unary minus
 * E expression list
 * C IF statement
 * L LOOP statement่
 * ์V symbol ref
 * = assignment
 * K constant
 * S literal string
 * A Expression
 */

/* node in the abstraction syntax tree */
/* all have common initial nodetype */
struct ast {
  int nodetype;
  struct ast *l;
  struct ast *r;
};

struct cond {
  int nodetype;      /* type C */
  struct ast *fStmt; /* condition */
  struct ast *sStmt;
  struct ast *tl; /* then branch or do list */
};

struct loop {
  int nodetype;     /* type L */
  struct ast *from; /* start number */
  struct ast *to;   /* end number */
  struct ast *tl;   /* then branch or do list */
};

struct lString {
  char *str;
  uint8_t label;
};

struct print {
  int nodetype;         /* type D H S */
  union arg {           /* argument of the print function */
    struct lString *ls; /* string argument */
    struct ast *exp;    /* expression argument */
  } arg;
};

struct numval {
  int nodetype; /* type N */
  int64_t number;
};

struct symref {
  int nodetype; /* type V */
  struct symbol *s;
};

struct symasgn {
  int nodetype; /* type = */
  struct symbol *s;
  struct ast *v; /* value */
};

/* simple symtab of fixed size */
struct symbol symtab[SEED];

struct symbol *lookup(char *);

/* build an ast */
struct ast *newNode(struct ast *l, struct ast *r, int nodetype);
struct ast *newPrintStmt(struct ast *exp, char *str, int nodetype);
struct ast *newVar(struct symbol *s);
struct ast *newAssign(struct symbol *s, struct ast *v);
struct ast *newNum(int64_t num);
struct ast *newIfe(struct ast *firstStmt, struct ast *secStmt, struct ast *tl);
struct ast *newVon(struct ast *from, struct ast *to, struct ast *tl);

/* evaluate an ast */
int64_t eval(struct ast *);
void asmGen(struct ast *);

/* delete and free an ast */
void freeNode(struct ast *);

/* interface to the lexer */
extern int yylineno; /* from lexer */
void yyerror(char *s, ...);