commit 8efcd411fee4e7103cff7b027fca38290cdaa6f7
parent 90d016980f47fb4f760be2356e715f92af9a7af8
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 4 Feb 2015 10:52:32 -0200
own implementation for 'string.format("%a")' for C89 platforms
Diffstat:
M | lstrlib.c | | | 87 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- |
M | luaconf.h | | | 16 | ++++++++-------- |
2 files changed, 92 insertions(+), 11 deletions(-)
diff --git a/lstrlib.c b/lstrlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstrlib.c,v 1.221 2014/12/11 14:03:07 roberto Exp roberto $
+** $Id: lstrlib.c,v 1.223 2015/02/04 12:52:57 roberto Exp $
** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h
*/
@@ -797,6 +797,86 @@ static int str_gsub (lua_State *L) {
** =======================================================
*/
+#if !defined(lua_number2strx) /* { */
+
+/*
+** Hexadecimal floating-point formatter
+*/
+
+#include <math.h>
+
+#define SIZELENMOD (sizeof(LUA_NUMBER_FRMLEN)/sizeof(char))
+
+
+/*
+** Number of bits that goes into the first digit. It can be any value
+** between 1 and 4; the following definition tries to align the number
+** to nibble boundaries. The default is 1 bit, that aligns double
+** (1+52-bit mantissa) and quad precision (1+112-bit mantissa). For
+** float (24-bit mantissa) and 80-bit long double (64-bit mantissa), 4
+** does the alignment.
+*/
+#define L_NBFD ((sizeof(lua_Number) == 4 || sizeof(lua_Number) == 12) ? 4 : 1)
+
+
+/*
+** Add integer part of 'x' to buffer and return new 'x'
+*/
+static lua_Number adddigit (char *buff, int n, lua_Number x) {
+ double dd = l_mathop(floor)(x); /* get integer part from 'x' */
+ int d = (int)dd;
+ buff[n] = (d < 10 ? d + '0' : d - 10 + 'a'); /* add to buffer */
+ return x - dd; /* return what is left */
+}
+
+
+static int num2straux (char *buff, lua_Number x) {
+ if (x != x || x == HUGE_VAL || x == -HUGE_VAL) /* inf or NaN? */
+ return sprintf(buff, LUA_NUMBER_FMT, x); /* equal to '%g' */
+ else if (x == 0) { /* can be -0... */
+ sprintf(buff, LUA_NUMBER_FMT, x);
+ strcpy(buff + (buff[0] == '-' ? 1 : 0), "0x0p+0");
+ return strlen(buff);
+ }
+ else {
+ int e;
+ lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */
+ int n = 0; /* character count */
+ if (m < 0) { /* is number negative? */
+ buff[n++] = '-'; /* add signal */
+ m = -m; /* make it positive */
+ }
+ buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */
+ m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */
+ e -= L_NBFD; /* this digit goes before the radix point */
+ if (m > 0) { /* more digits? */
+ buff[n++] = '.'; /* add radix point */
+ do { /* add as many digits as needed */
+ m = adddigit(buff, n++, m * 16);
+ } while (m > 0);
+ }
+ n += sprintf(buff + n, "p%+d", e); /* add exponent */
+ return n;
+ }
+}
+
+
+static int lua_number2strx (lua_State *L, char *buff, const char *fmt,
+ lua_Number x) {
+ int n = num2straux(buff, x);
+ if (fmt[SIZELENMOD] == 'A') {
+ int i;
+ for (i = 0; i < n; i++)
+ buff[i] = toupper(uchar(buff[i]));
+ }
+ else if (fmt[SIZELENMOD] != 'a')
+ luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented");
+ return n;
+}
+
+#endif /* } */
+
+
/*
** Maximum size of each formatted item. This maximum size is produced
** by format('%.99f', minfloat), and is equal to 99 + 2 ('-' and '.') +
@@ -908,9 +988,10 @@ static int str_format (lua_State *L) {
nb = sprintf(buff, form, n);
break;
}
-#if defined(LUA_USE_AFORMAT)
case 'a': case 'A':
-#endif
+ addlenmod(form, LUA_NUMBER_FRMLEN);
+ nb = lua_number2strx(L, buff, form, luaL_checknumber(L, arg));
+ break;
case 'e': case 'E': case 'f':
case 'g': case 'G': {
addlenmod(form, LUA_NUMBER_FRMLEN);
diff --git a/luaconf.h b/luaconf.h
@@ -1,5 +1,5 @@
/*
-** $Id: luaconf.h,v 1.241 2015/01/16 17:15:52 roberto Exp roberto $
+** $Id: luaconf.h,v 1.242 2015/01/16 17:26:56 roberto Exp roberto $
** Configuration file for Lua
** See Copyright Notice in lua.h
*/
@@ -598,7 +598,7 @@
/*
@@ lua_strx2number converts an hexadecimal numeric string to a number.
-** In C99, 'strtod' does both conversions. Otherwise, you can
+** In C99, 'strtod' does that conversion. Otherwise, you can
** leave 'lua_strx2number' undefined and Lua will provide its own
** implementation.
*/
@@ -608,12 +608,13 @@
/*
-@@ LUA_USE_AFORMAT allows '%a'/'%A' specifiers in 'string.format'
-** Enable it if the C function 'printf' supports these specifiers.
-** (C99 demands it and Windows also supports it.)
+@@ lua_number2strx converts a float to an hexadecimal numeric string.
+** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
+** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
+** provide its own implementation.
*/
-#if !defined(LUA_USE_C89) || defined(LUA_USE_WINDOWS)
-#define LUA_USE_AFORMAT
+#if !defined(LUA_USE_C89)
+#define lua_number2strx(L,b,f,n) sprintf(b,f,n)
#endif
@@ -699,7 +700,6 @@
#define LUAL_BUFFERSIZE 8192
#else
#define LUAL_BUFFERSIZE ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer)))
-
#endif
/* }================================================================== */