/* The math library has just one function:
*
- * arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t *hooks);
+ * arith_t arith(arith_state_t *state, const char *expr);
*
- * The first argument is the math string to parse. All normal expansions must
- * be done already. i.e. no dollar symbols should be present.
+ * The expr argument is the math string to parse. All normal expansions must
+ * be done already. i.e. no dollar symbols should be present.
*
- * The second argument is a semi-detailed error description in case something
- * goes wrong in the parsing steps. Currently, those values are (for
- * compatibility, you should assume all negative values are errors):
- * 0 - no errors (yay!)
- * -1 - unspecified problem
- * -2 - divide by zero
- * -3 - exponent less than 0
- * -5 - expression recursion loop detected
+ * The state argument is a pointer to a struct of hooks for your shell (see below),
+ * and an error message string (NULL if no error).
*
- * The third argument is a struct pointer of hooks for your shell (see below).
- *
- * The function returns the answer to the expression. So if you called it
- * with the expression:
- * "1 + 2 + 3"
- * You would obviously get back 6.
+ * The function returns the answer to the expression. So if you called it
+ * with the expression:
+ * "1 + 2 + 3"
+ * you would obviously get back 6.
*/
/* To add support to a shell, you need to implement three functions:
*
- * lookupvar() - look up and return the value of a variable
+ * lookupvar() - look up and return the value of a variable
*
- * If the shell does:
- * foo=123
- * Then the code:
- * const char *val = lookupvar("foo");
- * Will result in val pointing to "123"
+ * If the shell does:
+ * foo=123
+ * Then the code:
+ * const char *val = lookupvar("foo");
+ * will result in val pointing to "123"
*
- * setvar() - set a variable to some value
+ * setvar() - set a variable to some value
*
- * If the arithmetic expansion does something like:
- * $(( i = 1))
- * Then the math code will make a call like so:
- * setvar("i", "1", 0);
- * The storage for the first two parameters are not allocated, so your
- * shell implementation will most likely need to strdup() them to save.
+ * If the arithmetic expansion does something like:
+ * $(( i = 1))
+ * then the math code will make a call like so:
+ * setvar("i", "1", 0);
+ * The storage for the first two parameters are not allocated, so your
+ * shell implementation will most likely need to strdup() them to save.
*
- * endofname() - return the end of a variable name from input
+ * endofname() - return the end of a variable name from input
*
- * The arithmetic code does not know about variable naming conventions.
- * So when it is given an experession, it knows something is not numeric,
- * but it is up to the shell to dictate what is a valid identifiers.
- * So when it encounters something like:
- * $(( some_var + 123 ))
- * It will make a call like so:
- * end = endofname("some_var + 123");
- * So the shell needs to scan the input string and return a pointer to the
- * first non-identifier string. In this case, it should return the input
- * pointer with an offset pointing to the first space. The typical
- * implementation will return the offset of first char that does not match
- * the regex (in C locale): ^[a-zA-Z_][a-zA-Z_0-9]*
+ * The arithmetic code does not know about variable naming conventions.
+ * So when it is given an experession, it knows something is not numeric,
+ * but it is up to the shell to dictate what is a valid identifiers.
+ * So when it encounters something like:
+ * $(( some_var + 123 ))
+ * It will make a call like so:
+ * end = endofname("some_var + 123");
+ * So the shell needs to scan the input string and return a pointer to the
+ * first non-identifier string. In this case, it should return the input
+ * pointer with an offset pointing to the first space. The typical
+ * implementation will return the offset of first char that does not match
+ * the regex (in C locale): ^[a-zA-Z_][a-zA-Z_0-9]*
*/
-/* To make your life easier when dealing with optional 64bit math support,
- * rather than assume that the type is "signed long" and you can always
- * use "%ld" to scan/print the value, use the arith_t helper defines. See
- * below for the exact things that are available.
- */
+#ifndef SHELL_MATH_H
+#define SHELL_MATH_H 1
-#ifndef _SHELL_MATH_
-#define _SHELL_MATH_
+PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
-#if ENABLE_SH_MATH_SUPPORT_64
+#if ENABLE_FEATURE_SH_MATH_64
typedef long long arith_t;
-#define arith_t_fmt "%lld"
-#define strto_arith_t strtoll
+#define ARITH_FMT "%lld"
+#define strto_arith_t strtoull
#else
typedef long arith_t;
-#define arith_t_fmt "%ld"
-#define strto_arith_t strtol
+#define ARITH_FMT "%ld"
+#define strto_arith_t strtoul
#endif
-typedef const char *(*arith_var_lookup_t)(const char *name);
-typedef void (*arith_var_set_t)(const char *name, const char *val, int flags);
-typedef char *(*arith_var_endofname_t)(const char *name);
-typedef struct arith_eval_hooks {
- arith_var_lookup_t lookupvar;
- arith_var_set_t setvar;
- arith_var_endofname_t endofname;
-} arith_eval_hooks_t;
+typedef const char* FAST_FUNC (*arith_var_lookup_t)(const char *name);
+typedef void FAST_FUNC (*arith_var_set_t)(const char *name, const char *val);
+//typedef const char* FAST_FUNC (*arith_var_endofname_t)(const char *name);
+
+typedef struct arith_state_t {
+ const char *errmsg;
+ arith_var_lookup_t lookupvar;
+ arith_var_set_t setvar;
+// arith_var_endofname_t endofname;
+ void *list_of_recursed_names;
+} arith_state_t;
+
+arith_t FAST_FUNC arith(arith_state_t *state, const char *expr);
-arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t*);
+POP_SAVED_FUNCTION_VISIBILITY
#endif
projects / oweals / busybox.git / blobdiff