tanks

forf.h

  1#pragma once
  2
  3#include <inttypes.h>
  4#include <stdio.h>
  5
  6#define MAX_TOKEN_LEN 20
  7#define MAX_CMDSTACK 200
  8
  9struct forf_env;
 10
 11enum forf_value_type {
 12  forf_type_number,
 13  forf_type_proc,
 14  forf_type_stack_begin,
 15  forf_type_stack_end,
 16};
 17
 18enum forf_error_type {
 19  forf_error_none,
 20  forf_error_runtime,
 21  forf_error_parse,
 22  forf_error_underflow,
 23  forf_error_overflow,
 24  forf_error_type,
 25  forf_error_noproc,
 26  forf_error_divzero,
 27};
 28
 29extern char *forf_error_str[];
 30
 31typedef void(forf_proc)(struct forf_env *);
 32
 33struct forf_value {
 34  enum forf_value_type type;
 35  union {
 36    forf_proc *p;
 37    long i;
 38  } v;
 39};
 40
 41struct forf_stack {
 42  size_t size;
 43  size_t top;
 44  struct forf_value *stack;
 45};
 46
 47struct forf_memory {
 48  size_t size;
 49  long *mem;
 50};
 51
 52struct forf_lexical_env {
 53  char *name;
 54  forf_proc *proc;
 55};
 56
 57struct forf_env {
 58  enum forf_error_type error;
 59  struct forf_lexical_env *lenv;
 60  struct forf_stack *data;
 61  struct forf_stack *command;
 62  struct forf_memory *memory;
 63  void *udata;
 64};
 65
 66/*
 67 *
 68 * Main entry points
 69 *
 70 */
 71
 72/** Initialize a memory structure, given an array of longs */
 73void forf_memory_init(struct forf_memory *m, long *values, size_t size);
 74
 75/** Initialize a stack, given an array of values */
 76void forf_stack_init(struct forf_stack *s, struct forf_value *values,
 77                     size_t size);
 78
 79void forf_stack_reset(struct forf_stack *s);
 80void forf_stack_copy(struct forf_stack *dst, struct forf_stack *src);
 81int forf_stack_push(struct forf_stack *s, struct forf_value *v);
 82int forf_stack_pop(struct forf_stack *s, struct forf_value *v);
 83
 84/** Pop a number off the data stack */
 85long forf_pop_num(struct forf_env *env);
 86
 87/** Push a number onto the data stack */
 88void forf_push_num(struct forf_env *env, long i);
 89
 90/** Pop a whole stack */
 91struct forf_stack forf_pop_stack(struct forf_env *env);
 92
 93/** The base lexical environment */
 94extern struct forf_lexical_env forf_base_lexical_env[];
 95
 96/** Extend a lexical environment */
 97int forf_extend_lexical_env(struct forf_lexical_env *dest,
 98                            struct forf_lexical_env *src, size_t size);
 99
100/** Initialize a forf runtime environment.
101 *
102 * data, cmd, and mem should have already been initialized
103 */
104void forf_env_init(struct forf_env *env, struct forf_lexical_env *lenv,
105                   struct forf_stack *data, struct forf_stack *cmd,
106                   struct forf_memory *mem, void *udata);
107
108/** The type of a getch function (used for parsing) */
109typedef int(forf_getch_func)(void *);
110
111/** Parse something by calling getch(datum)
112 *
113 * Returns the character at which an error was encountered, or
114 * 0 for successful parse.
115 */
116int forf_parse_stream(struct forf_env *env, forf_getch_func *getch,
117                      void *datum);
118
119/** Parse a buffer */
120int forf_parse_buffer(struct forf_env *env, char *buf, size_t len);
121
122/** Parse a string */
123int forf_parse_string(struct forf_env *env, char *str);
124
125/** Parse a FILE * */
126int forf_parse_file(struct forf_env *env, FILE *f);
127
128/** Evaluate the topmost value on the command stack */
129int forf_eval_once(struct forf_env *env);
130
131/** Evaluate the entire command stack */
132int forf_eval(struct forf_env *env);