shell/math.h: update comments, rearrange struct members for smaller code

function                                             old     new   delta
arith_apply                                         1000     998      -2
evaluate_string                                     1414    1406      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-10)             Total: -10 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 5 insertions, 23 deletions

diff --git a/shell/math.c b/shell/math.c
index 56f866b..6196a6a 100644
--- a/shell/math.c
+++ b/shell/math.c
@@ -926,9 +926,9 @@ dbg("    numstack:%d val:%lld '%s'", (int)(numstackptr - numstack), numstackptr[
 arith_t FAST_FUNC
 arith(arith_state_t *math_state, const char *expr)
 {
+	math_state->evaluation_disabled = 0;
 	math_state->errmsg = NULL;
 	math_state->list_of_recursed_names = NULL;
-	math_state->evaluation_disabled = 0;
 	return evaluate_string(math_state, expr);
 }
 
diff --git a/shell/math.h b/shell/math.h
index 452ddad..9812184 100644
--- a/shell/math.h
+++ b/shell/math.h
@@ -6,7 +6,6 @@
  *
  * See math.c for internal documentation.
  */
-
 /* The math library has just one function:
  *
  * arith_t arith(arith_state_t *state, const char *expr);
@@ -22,7 +21,6 @@
  * "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
@@ -36,28 +34,12 @@
  * setvar() - set a variable to some value
  *
  *	If the arithmetic expansion does something like:
- *		$(( i = 1))
+ *		$((i = 1))
  *	then the math code will make a call like so:
- *		setvar("i", "1", 0);
+ *		setvar("i", "1");
  *	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
- *
- *	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]*
  */
-
 #ifndef SHELL_MATH_H
 #define SHELL_MATH_H 1
 
@@ -75,11 +57,11 @@ 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 struct arith_state_t {
+	uint64_t              evaluation_disabled;
 	const char           *errmsg;
+	void                 *list_of_recursed_names;
 	arith_var_lookup_t    lookupvar;
 	arith_var_set_t       setvar;
-	uint64_t              evaluation_disabled;
-	void                 *list_of_recursed_names;
 } arith_state_t;
 
 arith_t FAST_FUNC arith(arith_state_t *state, const char *expr);