Added special-case handling to %E, added +inf and -inf handling, test cases

2 files changed, 23 insertions, 6 deletions

diff --git a/printf.c b/printf.c
index 0ee5c3e..62cc52c 100644
--- a/printf.c
+++ b/printf.c
@@ -316,6 +316,7 @@ static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t
 

 

 #if defined(PRINTF_SUPPORT_FLOAT)

+#include <math.h>

 #if defined(PRINTF_SUPPORT_EXPONENTIAL)

 // forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT

 static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags);

@@ -330,10 +331,13 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
   // powers of 10

   static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };

 

-  // test for NaN

-  if (value != value) {

-    return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);	// ensure value is padded as required

-  }

+  // test for special values

+  if (value != value)

+    return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);

+  if (value < -DBL_MAX)

+    return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags);

+  if (value > DBL_MAX)

+	return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4 : 3, width, flags);

 

   // test for very large values

   // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad

@@ -448,9 +452,12 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
 }

 

 #if defined(PRINTF_SUPPORT_EXPONENTIAL)

-#include <math.h>

 static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)

 {

+  // check for special values

+  if ((value != value)||(value > DBL_MAX)||(value < -DBL_MAX))

+	return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);

+  

   // determine the sign

   bool negative = value < 0;

   if (negative) value = -value;

diff --git a/test/test_suite.cpp b/test/test_suite.cpp
index 875fa82..27efa4e 100644
--- a/test/test_suite.cpp
+++ b/test/test_suite.cpp
@@ -1045,9 +1045,19 @@ TEST_CASE("length", "[]" ) {
 TEST_CASE("float", "[]" ) {

   char buffer[100];

 

-  test::sprintf(buffer, "%8f", NAN);   // using the NAN macro of math.h

+  // test special-case floats using math.h macros

+  test::sprintf(buffer, "%8f", NAN);

   REQUIRE(!strcmp(buffer, "     nan"));

 

+  test::sprintf(buffer, "%8f", INFINITY);

+  REQUIRE(!strcmp(buffer, "     inf"));

+

+  test::sprintf(buffer, "%-8f", -INFINITY);

+  REQUIRE(!strcmp(buffer, "-inf    "));

+

+  test::sprintf(buffer, "%+8e", INFINITY);

+  REQUIRE(!strcmp(buffer, "    +inf"));

+  

   test::sprintf(buffer, "%.4f", 3.1415354);

   REQUIRE(!strcmp(buffer, "3.1415"));