Initial commit: now Turing complete!

1 files changed, 126 insertions, 0 deletions

diff --git a/lith.h b/lith.h
new file mode 100644
index 0000000..fa0960c
--- /dev/null
+++ b/lith.h
@@ -0,0 +1,126 @@
+/* lith: library header */
+#ifndef lith_h
+#define lith_h
+
+#include <stddef.h>
+
+typedef struct lith_value lith_value;
+typedef struct lith_value lith_env;
+typedef struct lith_state lith_st;
+typedef struct lith_string lith_string;
+typedef enum lith_value_type lith_valtype;
+
+enum lith_error {
+    LITH_ERR_OK,
+    LITH_ERR_EOF,
+    LITH_ERR_SYNTAX,
+    LITH_ERR_NOMEM,
+    LITH_ERR_UNBOUND,
+    LITH_ERR_NARGS,
+    LITH_ERR_TYPE
+};
+
+enum lith_value_type {
+    LITH_TYPE_NIL,
+    LITH_TYPE_PAIR,
+    LITH_TYPE_BOOLEAN,
+    LITH_TYPE_INTEGER,
+    LITH_TYPE_NUMBER,
+    LITH_TYPE_STRING,
+    LITH_TYPE_SYMBOL,
+    LITH_TYPE_BUILTIN,
+    LITH_TYPE_CLOSURE,
+    
+    LITH_NTYPES /* number of types */
+};
+
+typedef lith_value *(*lith_builtin_function)(lith_st *, lith_value *);
+
+struct lith_value {
+    lith_valtype type;
+    union {
+        int boolean;
+        long integer;
+        double number;
+        struct lith_string { size_t len; char *buf; } string;
+        char *symbol;
+        struct { struct lith_value *car, *cdr; } pair;
+        lith_builtin_function function;
+    } value;
+};
+
+
+#define LITH_IS(p, q) ((p)->type == (q))
+#define LITH_IS_NIL(p) (LITH_IS(p, LITH_TYPE_NIL))
+
+#define LITH_SYM_EQ(S, s) !strcmp((S)->value.symbol, (s))
+
+#define LITH_CAR(p) ((p)->value.pair.car)
+#define LITH_CDR(p) ((p)->value.pair.cdr)
+#define LITH_CONS lith_make_pair
+
+struct lith_state {
+    enum lith_error error;
+    struct lith_error_state {
+        int success, manual;
+        char *msg, *sym, *name;
+        struct lith_error_state__argsize { size_t expected, got; int exact; } nargs;
+        struct lith_error_state__type { lith_valtype expected, got; size_t narg; } type;
+    } error_state;
+    char *types[LITH_NTYPES];
+    lith_value *nil;
+    lith_value *True, *False;
+    lith_value *symbol_table;
+    lith_env *global;
+    char *filename;
+};
+
+#define LITH_IS_ERR(L) ((L)->error != LITH_ERR_OK)
+#define LITH_TO_BOOL(B) ((!LITH_IS_NIL(B)) && !(LITH_IS(B, LITH_TYPE_BOOLEAN) && !((B)->value.boolean)))
+#define LITH_IN_BOOL(B) ((B) ? L->True : L->False)
+
+/* When a number is printed, how many digits you want after the decimal point */
+#ifndef LITH_NFP
+#define LITH_NFP 8
+#endif
+
+void lith_init(lith_st *);
+void lith_free(lith_st *);
+
+void lith_print_error(lith_st *, int);
+
+lith_value *lith_new_value(lith_st *);
+void lith_print_value(lith_value *);
+void lith_free_value(lith_value *);
+lith_value *lith_copy_value(lith_st *, lith_value *);
+
+lith_value *lith_make_integer(lith_st *, long);
+lith_value *lith_make_number(lith_st *, double);
+lith_value *lith_make_symbol(lith_st *, char *);
+lith_value *lith_make_string(lith_st *, char *, size_t);
+lith_value *lith_make_builtin(lith_st *, lith_builtin_function);
+lith_value *lith_make_closure(lith_st *, lith_env *, lith_value *, lith_value *);
+lith_value *lith_make_pair(lith_st *, lith_value *, lith_value *);
+
+lith_value *lith_get_symbol(lith_st *, char *);
+
+lith_value *lith_read_expr(lith_st *, char *, char **);
+
+lith_value *lith_eval_expr(lith_st *, lith_env *, lith_value *);
+
+lith_value *lith_apply(lith_st *, lith_value *f, lith_value *args);
+
+lith_env *lith_new_env(lith_st *, lith_env *);
+void lith_free_env(lith_env *);
+
+lith_value *lith_env_get(lith_st *, lith_env *, lith_value *);
+void lith_env_set(lith_st *, lith_env *, lith_value *, lith_value *);
+
+void lith_fill_env(lith_st *);
+
+int lith_expect_type(lith_st *, char *, size_t, lith_valtype, lith_value *);
+int lith_expect_nargs(lith_st *, char *, size_t, lith_value *, int);
+
+void lith_run_string(lith_st *, lith_env *, char *);
+
+#endif