Re: Exposing `scm_i_mem2number ()'

[ludovic.courtes@laas.fr (Ludovic Courtès)]

Hi,

ludovic.courtes@laas.fr (Ludovic Courtès) writes:

> libguile/
>
> 2006-02-16  Ludovic Courtès  <ludovic.courtes@laas.fr>
>
> 	* numbers.c (scm_i_mem2number): Renamed to
> 	`scm_c_locale_string_to_number ()'.
> 	Updated callers.
>     
> 	* numbers.h: Updated function declaration.
>
> 	* print.c: Updated callers.
>
> 	* read.c: Likewise.
>
>
> doc/ref/
>
> 2006-02-16  Ludovic Courtès  <ludovic.courtes@laas.fr>
>
> 	* api-data.texi (Conversion): Documented
> 	`scm_c_locale_string_to_number ()'.

Below is an updated version of this patch.  It basically augments the
documentation of `scm_c_locale_string_to_number ()' to make it clear
that the word `locale' is about encoding, _not_ number representation.

While writing it, it occurred to me that R5RS does not make it clear
whether `string->number' converts from a number's external
representation or not.  I.e., it is not clear whether the two following
forms are equivalent:

  1.  (string->number str)

  2.  (with-input-from-string str read)

I believe most implementations and users assume that they are but I
couldn't find any evidence about it.  Opinions?

Thanks,
Ludovic.


--- orig/doc/ref/api-data.texi
+++ mod/doc/ref/api-data.texi
@@ -1031,6 +1031,18 @@
 @code{string->number} returns @code{#f}.
 @end deffn
 
+@deffn {C Function} scm_c_locale_string_to_number (string, len, radix)
+Like @code{scm_string_to_number ()}, return a number (a Scheme object)
+whose representation is expressed by the given C string @var{string}
+of size @var{len} octets (@var{string} does not need to be
+null-terminated).  @var{radix} must be of type @code{unsigned int}.
+
+Note that the word @code{locale} in the function name only means that
+@var{string} is encoded using the current locale encoding.  The number
+representation itself, as a string, is locale-independent: it is the
+@emph{external representation} of a number, as defined by R5RS
+@inforef{External representation, , r5rs}.
+@end deffn
 
 @node Complex
 @subsubsection Complex Number Operations


--- orig/libguile/numbers.c
+++ mod/libguile/numbers.c
@@ -2937,7 +2937,8 @@
 enum t_radix {NO_RADIX=0, DUAL=2, OCT=8, DEC=10, HEX=16};
 
 SCM
-scm_i_mem2number (const char* mem, size_t len, unsigned int default_radix)
+scm_c_locale_string_to_number (const char* mem, size_t len,
+			       unsigned int default_radix)
 {
   unsigned int idx = 0;
   unsigned int radix = NO_RADIX;
@@ -3043,9 +3044,9 @@
   else
     base = scm_to_unsigned_integer (radix, 2, INT_MAX);
 
-  answer = scm_i_mem2number (scm_i_string_chars (string),
-			     scm_i_string_length (string),
-			     base);
+  answer = scm_c_locale_string_to_number (scm_i_string_chars (string),
+					  scm_i_string_length (string),
+					  base);
   scm_remember_upto_here_1 (string);
   return answer;
 }


--- orig/libguile/numbers.h
+++ mod/libguile/numbers.h
@@ -215,7 +215,8 @@
 SCM_API int scm_print_real (SCM sexp, SCM port, scm_print_state *pstate);
 SCM_API int scm_print_complex (SCM sexp, SCM port, scm_print_state *pstate);
 SCM_API int scm_bigprint (SCM exp, SCM port, scm_print_state *pstate);
-SCM_API SCM scm_i_mem2number (const char *mem, size_t len, unsigned int radix);
+SCM_API SCM scm_c_locale_string_to_number (const char *mem, size_t len,
+					   unsigned int radix);
 SCM_API SCM scm_string_to_number (SCM str, SCM radix);
 SCM_API SCM scm_bigequal (SCM x, SCM y);
 SCM_API SCM scm_real_equalp (SCM x, SCM y);


--- orig/libguile/print.c
+++ mod/libguile/print.c
@@ -153,8 +153,8 @@
 
 #ifdef GUILE_DEBUG /* Used for debugging purposes */
 
-SCM_DEFINE (scm_current_pstate, "current-pstate", 0, 0, 0, 
-           (),
+SCM_DEFINE (scm_current_pstate, "current-pstate", 0, 0, 0,
+	    (void),
 	    "Return the current-pstate -- the car of the\n"
 	    "@code{print_state_pool}.  @code{current-pstate} is only\n"
 	    "included in @code{--enable-guile-debug} builds.")
@@ -327,7 +327,7 @@
   if (len == 0 || str[0] == '\'' || str[0] == '`' || str[0] == ','
       || quote_keywordish_symbol (str, len)
       || (str[0] == '.' && len == 1)
-      || scm_is_true (scm_i_mem2number(str, len, 10)))
+      || scm_is_true (scm_c_locale_string_to_number (str, len, 10)))
     {
       scm_lfwrite ("#{", 2, port);
       weird = 1;


--- orig/libguile/read.c
+++ mod/libguile/read.c
@@ -506,7 +506,8 @@
 	       * does only consist of octal digits.  Finally, it should be
 	       * checked whether the resulting fixnum is in the range of
 	       * characters.  */
-	      p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 8);
+	      p = scm_c_locale_string_to_number (scm_i_string_chars (*tok_buf),
+						 j, 8);
 	      if (SCM_I_INUMP (p))
 		return SCM_MAKE_CHAR (SCM_I_INUM (p));
 	    }
@@ -644,7 +645,7 @@
 	/* Shortcut:  Detected symbol '+ or '- */
 	goto tok;
 
-      p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 10);
+      p = scm_c_locale_string_to_number (scm_i_string_chars (*tok_buf), j, 10);
       if (scm_is_true (p))
 	return p;
       if (c == '#')



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